WILDLIFE RESEARCH REPORTS
This series comprises reports of research relating to birds, mammals,
and other wildlife and their ecology, and specialized bibliographies
on these, issued for wildlife research and management specialists. The
Service distributes these reports to official agencies, to libraries,
and to researchers in fields related to the Service's work.
Library of Congress Cataloging in Publication Data
Conservation of marine birds of northern North America.
(Wildlife research report: 11)
Supt. of Docs. no.: I 49.47/4:11
1. Sea birds--North America--Congresses. 2. Sea birds--Northwest,
Pacific--Congresses. 3. Birds, Protection of--North
America--Congresses. 4. Birds, Protection of--Northwest,
Pacific--Congresses. 5. Birds--North America--Congresses. 6.
Birds--Northwest, Pacific--Congresses. I. Bartonek, James C. II.
Natural Resources Council of America. III. United States. Fish and
Wildlife Service. IV. Series.
QL681.C59 333.9'5 79-607005
Use of trade names does not imply U.S. Government endorsement of
commercial products.
CONSERVATION OF MARINE BIRDS OF NORTHERN NORTH AMERICA
[Illustration]
CONSERVATION OF MARINE BIRDS OF NORTHERN NORTH AMERICA
Papers from the International Symposium held at the Seattle Hyatt
House, Seattle, Washington, 13-15 May 1975
Edited by
James C. Bartonek and David N. Nettleship
Sponsored by
Natural Resources Council of America
National Audubon Society
National Wildlife Federation
U.S. Department of the Interior, Fish and Wildlife Service
UNITED STATES DEPARTMENT OF THE INTERIOR
FISH AND WILDLIFE SERVICE
Wildlife Research Report 11
Washington, D.C. • 1979
Dedicated to the Memory
of
Robert D. Bergman, Leonard A. Boughton, and J. Larry Haddock, Wildlife
Biologists of the Fish and Wildlife Service, and Robert Johnson, Pilot
of the Office of Aircraft Services, all of the U.S. Department of the
Interior, who perished in the Gulf of Alaska on 30 September 1974 while
conducting aerial surveys of marine birds,
and to
Einar Brun, Professor of Zoology in Tromsø University and a contributor
to these proceedings, who perished in the Vega Sea on 13 July 1976 when
returning from making aerial surveys of marine birds.
Contents
Page
Foreword, by Harvey K. Nelson vii
Introduction, by Lynn A. Greenwalt ix
Marine Environment of Birds 1
Long-term Climatic and Oceanographic Cycles Regulating Seabird
Distributions and Numbers, by M. T. Myres 3
Sea Ice as a Factor in Seabird Distribution and Ecology in the Beaufort,
Chukchi, and Bering Seas, by George J. Divoky 9
Status of Marine Bird Populations 19
Distribution and Status of Marine Birds Breeding Along the
Coasts of the Chukchi and Bering Seas, by James C. Bartonek and
Spencer G. Sealy 21
Breeding Distribution and Status of Marine Birds in the Aleutian
Islands, Alaska, by Palmer C. Sekora, G. Vernon Byrd, and Daniel
D. Gibson 33
The Historical Status of Nesting Seabirds of the Northern and Western
Gulf of Alaska, by LeRoy W. Sowl 47
Status and Distribution of Breeding Seabirds of Southeastern Alaska,
British Columbia, and Washington, by David A. Manuwal and
R. Wayne Campbell 73
The Biology and Ecology of Marine Birds in the North 93
Trophic Relations of Seabirds in the Northeastern Pacific Ocean
and Bering Sea, by David G. Ainley and Gerald A. Sanger 95
Population Dynamics in Northern Marine Birds, by William H. Drury 123
Time-energy Use and Life History Strategies of Northern Seabirds,
by Erica H. Dunn 141
Zoogeography and Taxonomic Relationships of Seabirds in
Northern North America, by M. D. F. Udvardy 167
Conflicts Between the Conservation of Marine Birds and Uses of
Other Resources 171
Social and Economic Values of Marine Birds, by David R. Cline,
Cynthia Wentworth, and Thomas W. Barry 173
Resource Development Along Coasts and on the Ocean Floor: Potential
Conflicts with Marine Bird Conservation, by Donald E. McKnight
and C. Eugene Knoder 183
Mortality to Marine Birds Through Commercial Fishing, by Warren B. King,
R. G. B. Brown, and Gerald A. Sanger 195
Interactions Among Marine Birds and Commercial Fish in the Eastern
Bering Sea, by Richard R. Straty and Richard E. Haight 201
Interrelations Between Seabirds and Introduced Animals,
by Robert D. Jones, Jr., and G. Vernon Byrd 221
Oil Vulnerability Index for Marine Oriented Birds, by James G. King
and Gerald A. Sanger 227
Programs and Authorities Related to Marine Bird Conservation 241
Programs and Authorities Related to Marine Bird Conservation in
Washington State, by Ralph W. Larson 243
Programs and Authorities of the Province of British Columbia
Related to Marine Bird Conservation, by W. T. Munro and R. Wayne
Campbell 247
Petroleum Industry's Role in Marine Bird Conservation, by Keith
G. Hay 251
Conservation of Marine Birds in Other Lands 259
Conservation of Marine Birds in New Zealand, by Gordon R. Williams 261
Marine Birds in the Danish Monarchy and Their Conservation,
by Finn Salomonsen 267
Present Status and Trends in Population of Seabirds in Norway,
by Einar Brun 289
Symposium Summary 303
Conservation of Marine Birds of Northern North America--a Summary,
by Ian C. T. Nisbet 305
Appendix. Papers and oral summaries presented at the symposium but which
do not appear in this publication 319
Foreword
The international symposium "Conservation of Marine Birds of Northern
North America" was convened because of a growing awareness that not
all was well with our marine birds. The symposium provided a forum
for scientists, governmental administrators, conservationists, and
laypeople to discuss the diverse topics and issues that we must all
understand if we are to act both responsively and responsibly to assure
that marine birds will not be lost through our neglect.
The symposium was cosponsored by the Natural Resources Council of
America, National Audubon Society, National Wildlife Federation,
and the U.S. Department of the Interior, Fish and Wildlife Service;
additional support was provided by the Canadian Wildlife Service,
the International Association of Game, Fish, and Conservation
Commissioners, the Pacific Seabird Group, the Sierra Club, the
Smithsonian Institution, the Wildlife Management Institute, and the
Wildlife Society.
Persons interested and knowledgeable in the many and varied
aspects of marine bird conservation were invited to participate
in this symposium. There were 139 registered and several score of
unregistered participants in attendance. Major topics treated were:
(1) socioeconomic considerations and conservation of marine birds; (2)
the marine environment of birds; (3) status of marine bird populations
on land and sea; (4) the biology and ecology of marine birds in the
North; (5) conflicts between the conservation of marine birds and
uses of other resources; (6) programs and authorities related to the
conservation of marine birds; and (7) conservation of marine birds in
other lands.
The objective of the symposium was to identify problems and the needed
information and programs necessary for the conservation of marine birds
of northern North America. For the purpose of this symposium the term
"northern North America" referred to the coasts of Washington, British
Columbia, Alaska, Yukon Territory, and Northwest Territories and the
adjacent North Pacific and Arctic Oceans. "Marine bird" was defined as
being any bird using marine or estuarine waters. Speakers were asked
to describe the status of information or the state of the art as it
pertained to their topic within the limitations set by the objective
of the symposium. Examples from other regions and of bird species
not found in the regions of concern were to be used for comparative
purposes when little pertinent information was known for regions or
species of concern. Speakers were asked to identify the gaps in the
knowledge and methodology that are most critical to their topic.
I believe that this symposium was particularly successful in that it
provided a timely forum for many scientists who were about to embark on
studies of marine birds in those areas of Alaska and California being
considered for outer continental shelf oil and gas exploration and
development. These published proceedings may be of lesser importance
from that standpoint because some data, particularly those on
populations, are out of date. However, I believe that the proceedings
will long be of importance to biologists and administrators alike in
charting their respective courses to ultimately assure conservation of
this valuable avian resource.
Many people from many organizations and agencies worked hard to put
together the symposium in the relatively short time of about 8 months.
Nathaniel P. Reed was the person primarily responsible for bringing
this symposium to fruition. The Steering Committee was composed of
Daniel A. Poole, John S. Gottschalk, David N. Nettleship, Amos S. Eno,
C. Eugene Knoder, Warren G. King, Louis Clapper, Robert Hughes, Fred G.
Evenden, James C. Bartonek, and me. James C. Bartonek, Warren G. King,
David N. Nettleship (Co-chairmen), C. Eugene Knoder, David A. Manuwal,
William H. Drury, and Spencer G. Sealy served on the Program Committee.
David A. Manuwal and Terence R. Wahl arranged trips for persons to
observe pelagic birds off the Washington coast and other birds on
Skagit Flats. C. Eugene Knoder handled financial matters. John A. Sayre
and Richard Bauer made arrangements for facilities and entertainment.
Elaine Rhode prepared the program and abstracts for printing. John
Pitcher kindly contributed the artwork used in this publication as well
as that used in the program and abstracts.
George Reiger made general introductions to the symposium; Spencer
G. Sealy, Daniel W. Anderson, and I served as Session Chairmen; and
James C. Bartonek served as General Chairman. Elvis J. Stahr was guest
speaker at the symposium banquet.
Most credit for the success of this symposium goes to the 52 persons
who as authors, coauthors, or summarizers of sessions presented
much meaningful information in their presentations, during recorded
discussions, and during many informal occasions. I wish to make special
recognition of Ian C. T. Nisbet for his skillful summary of the
symposium.
Editorial assistance in preparing the proceedings was provided by
Judith Brogan.
Harvey K. Nelson
_Chairman of Symposium and
Director of Wildlife Resources_
Introduction
Migratory birds make up a resource that is shared by many people
of many nations. Public awareness of marine birds--their manifold
values, ecological requirements, and problems--is prerequisite to
their protection. I am proud that the Fish and Wildlife Service can
further this needed awareness by publishing these proceedings of the
international symposium "Conservation of Marine Birds of Northern North
America."
Lynn A. Greenwalt, _Director
Fish and Wildlife Service_
MARINE ENVIRONMENT OF BIRDS
Long-term Climatic and Oceanographic Cycles Regulating Seabird
Distributions and Numbers
by
M. T. Myres
Department of Biology, University of Calgary
Calgary, Alberta, Canada T2N 1N4
Abstract
Seabird ornithologists have generally paid
little attention to the possible roles played
by long-term climatic cycles or air-ocean
interactions on population changes at
established colonies or on the processes of
colony establishment or extinction. Yet, a
rapidly expanding literature in the physical
sciences suggests that seabird numbers are not
naturally stable at particular colonies for any
great length of time. It is suggested that the
establishment of new colonies at one end of
the range may counter the decline of colonies
at the other end. Perhaps these changes in
small marginal colonies are important, and they
may be more indicative and significant (when
detected and explained) than are much larger
changes in numbers in bigger reproductive units
in the center of a species' range. Fluctuations
in seabird numbers must in future be first
considered as possible responses either to
short-term, or turnarounds in longer term,
natural climatic or oceanographic cycles, or to
trends ranging in length from a few years to at
least several decades.
During the last 30 years extensive literature in the fields of physical
and biological oceanography has accumulated that is not readily
accessible to the nonprofessional student of seabirds and not as
widely understood by career seabird ornithologists as it should be.
This literature in oceanography and marine fisheries is as extensive
in Russian and Japanese together as in the main languages of Western
Europe combined; this abundance compounds the problem of becoming
familiar with it if, as a student of seabirds, one's interest in the
literature is initially somewhat marginal. Nevertheless, to achieve the
best possible appreciation of the oceanographic influences affecting
seabirds, particularly in the north Pacific Ocean and its adjacent
embayment seas, it is necessary to make the effort.
Because of the rigor of carrying out their primary duties while at sea,
only a very few North American and European oceanographers or fishery
biologists have found time to interest themselves in seabirds and then,
with a few notable individual exceptions, only as an off-duty pastime.
The reason is not far to seek. It is far less important to examine the
ecology of organisms at the next highest level of the food chain to the
ones that are the primary concern than it is to examine the next lowest
level (the food of the fishes or, in the case of phytoplankton, the
physical and chemical environment in which the organisms grow best).
Seabirds are at the very top of the marine food chain, and they are not
wholly aquatic in any case since they mainly travel through the air
rather than the water and reproduce on land rather than in the sea.
Only with the relatively recent recognition that seabirds contribute to
the recycling of nutrients back into the ocean to an important degree,
have seabirds gained a new scientific constituency.
At about the same time, governments have begun to recognize that
seabirds are relatively easily examined indicators of the presence of
unseen chemical pollutants in coastal seas, perhaps primarily for the
very same reasons that they were previously so largely ignored; namely,
that they are at the top of the food chains (and so accumulate the
most-persistent and least-degradable pollutants) and that the on-land
failures in their reproductive biology are readily visible.
During the last 10 years, it has become evident that yet another
fundamental science is even more basic to the achievement of a balanced
and in-depth understanding of the influence of the environment
upon seabirds--the combined field of astrophysics, geophysics, and
climatology. New developments in this field (when they are not
published in _Nature_ or _Science_) appear in journals that are less
familiar to seabird ornithologists than those in which the fishery
biologists and biological oceanographers publish their findings.
Unfortunately, important advances in understanding the dynamics and
energy transport mechanisms of both the atmosphere and the water masses
of the oceans are not being picked up by students of seabirds because
of the natural lag in communication that occurs between disparate
disciplines. Only in the last few years have oceanographers and
climatologists been invited to address gatherings of ornithologists,
and the modesty with which they have sometimes done so has limited the
impact of their offerings.
At this symposium, it was left to a biologist with no pretentions in
either physics or mathematics to demonstrate the need for seabird
ornithologists to understand basic environmental processes well beyond
their usual range of interests. I did so with a series of slides taken
from this "other" literature, and I had intended to include in the
published version of this paper an extensive bibliography, subdivided
into category groupings, so that seabird ornithologists could make
their own selection of the points in the spectrum at which they most
needed information.
Unfortunately, limitations upon space in this volume, daily additions
to the exploding literature, and my own inability to keep up with
understanding this have forced me to omit any references and not to
attempt to expound detailed specific physical mechanisms.
Thus unencumbered here, I shall briefly outline instead what I perceive
to be some of the significance for seabird ornithology and conservation
of the rapidly expanding understanding of the oceans, the air-sea
interface, atmospheric dynamics, and influences upon the world's
climate of extraterrestrial events.
Small-scale or Short-term Influences
There is no need to dwell on the well-known events that could be
mentioned under this heading. Seabird ornithologists are familiar
with the fact that the atmosphere is the medium of seabirds both when
searching the ocean for feeding areas and when on migration, and also
a violent enemy, as when particular storms cause occasional "wrecks"
of seabirds inland from coastlines. As a refinement of the former,
Manikowski of Poland suggests that seabirds respond to the passage of
weather systems, so that their distribution over the open ocean may
be constantly changing. Whereas some species may attempt to avoid the
stormy conditions of low-pressure areas (cyclonic conditions), others
more highly specialized for exploiting the aerodynamic properties of
wind over a moving water surface may possibly, instead, try to avoid
large high-pressure regions (anticyclonic conditions with little or
no wind). My student, Juan Guzman, is attempting to determine whether
this may be so; if it is, it might be possible, for example, to predict
some things about the distribution patterns and population structure of
southern hemisphere shearwaters while they are visiting the oceans of
the northern hemisphere during the nonbreeding season.
In comparison with the "wrecks" brought about by storms, which are of
short duration and not usually very serious, seabird ornithologists are
also familiar with relatively brief and localized disasters caused by
changes in the ocean itself. The best-known example is a slight change
in the boundary of an ocean current (or other shift in the position of
a distinctive water mass) that results in the failure of food fishes to
appear as they normally would, close to breeding sites of conspicuous
colonial seabirds, such as the periodic shift in the El Niño off the
west coast of South America. A scarcely studied refinement of this
type of event would be the effects of less-pronounced oceanic changes
that might reduce the planktonic food supply of nocturnally active,
burrow-nesting seabirds. In such instances, the effects might also be a
breeding failure for only one or two seasons; in all probability such
events occur, but whether they are as likely to be detected by us is
problematical. However, the populations of most seabirds are probably
already adapted to survive short-term crises of this type because,
having long adult life spans, reproductive adults that fail to raise
young one year may mostly live to succeed in doing so in the next or
succeeding year, when the oceanic "anomaly" has disappeared. What
constitutes an "anomaly" will be considered again shortly.
A third critical condition for seabirds may be local or widespread,
temporary or final, or some combination of these. A single local spill,
or outfall, of a chemical pollutant will be short term if we can take
steps to alleviate the consequences or stem the flow. Alternately, we
may consider it to be long term if we take the view that it is one
additional act of violence resulting from the "progress" of Industrial
Man, and that it is never going to shift into reverse gear. We may
say that the effect on seabird populations of spills of oil products
or chemical pollutants in coastal waters of a region will be a "final
solution" for any that become wholly extinct before the oil wells go
dry or the industries fail. On the other hand, the effect will have
been merely a perturbation of the population if the species survives
and outlives these activities. Recent upturns in populations of
peregrine falcons _(Falco peregrinus)_ and pelicans _(Pelecanus sp.)_
in certain places where environmental controls have been enacted give
us hope that crises of several years' duration can be withstood by
at least those species that once were common in relation to their
respective food sources or available safe breeding habitats. The really
critical features to document are the means whereby abandoned breeding
sites are reoccupied and the time it takes.
It must never be forgotten that we know almost nothing about the
ecology of subadult or nonreproductive adult seabirds during the years
they are at sea unconfined by membership in a breeding unit and that
we know almost nothing about the activities of pelagic seabirds in the
nonbreeding season. These birds may be far from land and hard to study,
but what happens during those phases of their lives is basic to the
composition of the colony and condition of the birds when breeding.
A start would be to learn everything that is known and is being
discovered about the oceans by oceanographers and, thus forearmed, go
looking for the seabirds with certain questions clearly in mind.
Detecting the Effects of Long-term Cycles
A scientist's working life lasts only a few decades, and few studies of
seabirds by a single author or agency have been continued for longer
than 5-10 years on any one problem. Further, while we as individuals
may live to be equally active in a certain field of research 20 years
hence, our collective conscience and collective muscle consist of
several levels of government that tend to exhibit 4- or 5-year changes
of direction and priorities. Certainly, the civil service may live
on as an inertial recorder of collective experience. Certainly, too,
those who live under one form or another of dictatorship or, as in some
Canadian provinces, where conservative patterns of voting occur, may
experience a continuity of research and development and conservation
policies that exceed the 4- to 5-year turnaround pattern that is most
common. Yet, even these more continuous systems may come to an end
quite suddenly because of economic or political happenstance.
The point of this digression is to show that seabird ornithologists
must not rely on government programs to provide continuous data over
a long period of years--not, at least, in most countries. Monitoring
the biological circumstances of seabirds is not the same as recording
the temperature regularly by machine at a weather station, since this
activity is unlikely to be terminated unless the society collapses
altogether. We may know that in some countries the amateur naturalist
exists in such numbers that records of seabirds will continue to be
made whatever the circumstances. Nevertheless, planning of censuses
that will be repeated every 10 years is best assured if government
and career biologists combine with the amateur element, so that any
one of them can continue the work if any other element should be
incapacitated. At any one time, either the amateur or the government
or the university personnel may be the prime mover, and each of these
forms now exists in various countries.
What the scientific literature in the fields of the geophysical,
atmospheric, and oceanographic disciplines demonstrates is that natural
climatic oscillations probably range in length from the 11-year sunspot
cycle through several decades (or a human lifetime) to several hundred
years. So, when our children are the new trustees of seabird colonies
20 or 40 years hence, they must interpret their data using the full
range of physical as well as biological data that we can leave for
them. Indeed, the information is, I believe, already available over
a long enough period (since 1940 at least) to allow some speculative
interpretations of what may have been happening to our seabird
populations, whether or not we knew or had any evidence of it.
I have already suggested that extraterrestrial events, particularly
the 11-year sunspot cycle, are increasingly believed to influence the
atmosphere of this planet. The Chinese and Japanese have remarkably
precise records of the northern limits of certain agricultural crops
at particular times, the phenology of flowering, and the freezing of
lakes. These demonstrate long-term trends in overall climate in eastern
Asia that extend over hundreds of years. The climate of Japan is
influenced by the high-pressure area in winter over mainland East Asia.
There is evidence that severe ice conditions in the Bering Sea during
the early 1970's may have been due to an eastward shifting of this
high-pressure area. Again, the water mass of the Kuroshio Extension and
the West Wind Drift takes several years to travel across the Pacific
Ocean, and there is an established temperature variation that travels
like a slow wave with it. Off Japan, the Kuroshio Current periodically
develops meanders which slow the speed of the eastward flow. Cold and
warm "pools" of water approach the west coast of Canada and the western
United States from time to time.
Ocean currents are driven by the atmospheric motion above them, which
consists of several convective cells between the equator and each pole.
The outcome is zonal winds, such as the trade winds and the westerlies.
However, as the influence of the sun on the atmosphere is variable, the
input of heat and the extent of the major high-pressure areas vary,
as does the path of the jet stream. The recent droughts in northern
Africa and unusually heavy rains in Australia are both linked to a
southward shift of the Intertropical Convergence Zone in the atmosphere
and a "corrugation" of the wind circulation from a more normal zonal
(latitudinal) path. These shifts in the atmospheric circulation are
almost certainly transmitted also to the ocean currents and the marine
ecosystem, with the influence being felt for a long period of years.
One of the oceanic domains of the North Pacific is the transitional
domain, which lies east-west where the West Wind Drift impinges upon
the coasts of British Columbia and Washington State. It is precisely
in this sector that there was a well-documented "temperature anomaly"
in 1957-58. Since an anomaly implies something completely out of the
ordinary, I seriously question the appropriateness of the term for an
event that may or may not be recurrent (at the time it was a pronounced
variation from the oceanographic records accumulated up to that time,
but the period had not been a very long one). It is no coincidence that
the numbers of albatrosses recorded at Ocean Weather Station "Papa" was
higher during this warm-water "anomaly" than subsequently (indeed, an
18-year record of the seabirds recorded at "Papa" also exhibits other
interesting fluctuations from the base-line data in certain years).
Recent analyses of sediments from off the coast of California have
demonstrated long-term fluctuations in sardine populations extending
back at least 1,800 years, with increases lasting 20-150 years and
spaced 20-200 years apart. The number of anchovies declined steadily.
Yet until now, El Niño events have been treated as anomalies in
that region as well as off the coast of Peru. Just as we recognize
that different species of fish follow the warm water north on such
occasions, we must also recognize the rather distinct seabird species
assemblage that is trapped, as it were, in the Gulf of California.
Clearly, like the termination point of the West Wind Drift at about the
45-55° parallel, the coast of Baja California and southern California
State, from the 25-35° parallel where the California Current begins to
swing away from the coast to the west as the North Equatorial Current,
is another zone of instability.
I think that it is no accident that the southern limit of several
northern species of North Pacific seabirds ends in southeastern Alaska
or northern British Columbia, and that the northern limit of the
ranges of several other species occurs in Washington State or southern
British Columbia. Indeed, the west coast of Vancouver Island is not
rich in species, and several of those that exist are not present in
great numbers. This is a region of rather more variable conditions than
elsewhere, and species evidently find that it is difficult to colonize
and it quickly becomes unsuitable again. Since 1940, indeed, there has
been a parallel decline in the annual mean sea-surface temperature
at a number of coastal recording stations in British Columbia, and
this seems to have been a rebound from a less well-documented rise
in sea-surface temperatures during the 20 years before that, which
culminated in a peak around 1940. Salinity has likewise trended
downwards during the last 30 years. The seabird colony size data before
1960 are so nonquantitative that it is impossible to be sure what
changes in seabird populations and breeding sites may have taken place
in response to these physical changes.
The lesson is that we must now examine all future census and
distribution data with trends in sea-surface temperature and salinity
in mind as two of several likely factors influencing them. We must no
more ignore data outside our own field than a salmon ecologist might.
Conclusions
We know little of the accuracy of censuses of seabird numbers made
between 1850 and 1950. There has been a tendency to assume that
numbers of seabirds at long-established colonies have been relatively
unchanging, even though the expansion of some species into previously
unrecorded breeding sites in low numbers is well documented.
Contraction of breeding ranges, likewise, has most commonly been
attributed to the influence of man. Recent literature from the physical
sciences, on the contrary, suggests that seabird numbers at particular
colonies are most unlikely to have been stable for any great length
of time, at least at high or middle latitudes and particularly at
points where boundaries between currents impinge on continental coasts.
Indeed, some early estimates of colony sizes may not have been as much
in error as we may have assumed, neither when apparently too large nor
when apparently unlocated by previous visitors.
The halving of a large colony over a period of 20 to 50 years in
the middle of the range of a species and the establishment and
disappearance of smaller breeding groups at opposite extremes of the
range (both latitudinally and longitudinally), may equally reflect
natural long-term climatic or oceanographic changes and may naturally
be reversed at some time in the future, perhaps within half a century.
The implication for conservation of seabird colonies that are at the
contracting end of a species' range is that cultural rather than
biological criteria may be the best determinants.
Sea Ice as a Factor in Seabird Distribution and Ecology in the
Beaufort, Chukchi, and Bering Seas
by
George J. Divoky[1]
U.S. Fish and Wildlife Service
Fairbanks, Alaska
Abstract
Arctic sea ice has a variety of effects on
seabirds. Although the decrease in surface area
available for feeding and roosting is probably
the major restrictive effect, also important
are productivity of water covered by ice and
the reduced prey abundance in nearshore areas
due to ice scour. The most important benefit
that sea ice provides to seabirds is the
plankton bloom that occurs in the ice in the
spring. In the Beaufort and Chukchi seas this
bloom supports an under-ice fauna that is an
important food source for seabirds.
Sea ice is a major factor in the distribution and ecology of many of
the birds treated in this symposium. Sea ice is defined here as ice
formed by the freezing of seawater and includes both free floating pack
ice and the more stable shorefast ice. Since icebergs are composed of
ice of land origin, they are not discussed.
Before discussing the specific relationship of birds and sea ice in
the Beaufort, Chukchi, and Bering seas, I list the general effects
that arctic ice can have on seabirds. For purposes of discussion these
effects can be divided into negative effects, or disadvantages, and
positive effects, or advantages.
General Effects of Ice on Birds
_Negative Effects_
Sea Ice Decreases the Surface Area of Water
The decrease in the surface area of water is the simplest and most
immediate effect that sea ice has on birds. Ice acts as a barrier that
restricts the availability of food in the water. Surface feeders are
the most severely affected since, in general, ice cover of 50% reduces
the possible feeding area by half. The effect on diving species is not
as severe since, if open water is scattered throughout the ice, diving
species still have access to much of the prey in the water column and
benthos. When open water is scarce, however, diving species can become
concentrated in the available water, resulting in intense competition
for available prey. In certain situations the open water is used only
as a migratory pathway, but open water is necessary for birds that must
roost or feed.
Sea Ice Reduces Primary Productivity in the Water Column
Ice inhibits phytoplankton blooms in the water column, thus decreasing
the biological productivity of ice-covered waters. This inhibition
occurs in two ways:
• _By decreasing light penetration of the water column._--Much of the
sunlight reaching the ice is reflected by the ice and by snow on the
ice. The amount of light reaching the water depends on the angle of
the light, thickness of ice, and amount of snow cover. When the layer
of under-ice algae forms, it absorbs light and further reduces the
amount of light reaching the water (Bunt 1963). This reduction in light
reduces the depth of the euphotic zone.
• _By increasing the stability of the water column._--Increased
stability of the water column reduces the upwelling of nutrient-rich
waters into the euphotic zone. Ice stabilizes the water column
primarily by preventing wind-driven movement of surface waters and by
forming a layer of meltwater at the surface in the spring and summer
(Dunbar 1968).
Sea Ice Reduces Benthic and Intertidal Biota
Benthic flora and fauna can be reduced by the presence of ice in two
ways: In shallow water ice can freeze to the bottom for much of the
year and prevent the establishment of plant and animal populations;
and when ice floes are pushed together, they form underwater ice keels
that can scour the bottom when the ice moves. Both of these events not
only act directly to decrease benthic populations but also disturb the
sediment, making it less suitable for colonization. In areas with heavy
ice scour, sessile benthic populations can be greatly reduced, although
motile species may move into scoured areas during the ice-free period
in summer. In addition to preventing the establishment of sessile
benthic animal populations, ice scour also prevents the establishment
of beds of kelp and eelgrass _(Zostera marina)_, thus decreasing the
diversity and productivity of arctic inshore waters. Both kelp and
eelgrass beds are important feeding sites for birds in areas south of
the region affected by ice scour.
Sea Ice Allows Terrestrial Predators Access to Breeding Sites
The formation of ice between the mainland and offshore islands
allows the arctic fox _(Alopex lagopus)_ and other predators access
to the islands used by breeding birds. Foxes can become permanently
established on islands that have food sources during the period when
birds are absent from the island. Often, however, there is little to
attract foxes to the islands other than breeding birds. Because moats
form around many islands before the breeding birds arrive, foxes
are primarily a problem when moat formation is incomplete or when
the breakup of ice is late. Arctic foxes are found on the pack ice
throughout the summer and thus can visit islands that are separated
from the mainland by open water but are adjacent to the pack ice.
_Advantages_
Sea Ice Provides a Matrix and Substrate for an Ice-associated Plankton
Bloom and an Associated Under-ice Fauna
The first detailed studies on the blooms of diatoms that occur in the
lower levels of ice were done by Appollonio (1961). The importance
of this bloom in the energy budgets of arctic and subarctic seas has
only recently been realized (Alexander 1974; McRoy and Goering 1974).
In areas where ice is present throughout the year, the plankton bloom
supports a population of under-ice invertebrates. These populations
have been little studied but apparently consist primarily of copepods
and amphipods (Mohr and Geiger 1968). Feeding on the invertebrates
associated with the ice are two species of fish, polar cod _(Arctogadus
glacialis)_ and arctic cod _(Boreogadus saida)_. Andriashev (1968)
used the term cryopelagic to describe such fish, which are found in
the midwater zone but also are associated with ice during some part of
their life cycle.
The underside of multi-year ice has numerous ridges and pockets that
provide a heterogeneous environment for the under-ice fauna. This
environment is protected from disturbance from currents and wave action
by ice keels acting as barriers, which also provide shelter from
predators in the same manner as a coral reef. The overall effect of
the under-ice flora and fauna is to increase the diversity of surface
waters in arctic seas by creating an inverted benthic biota.
Sea Ice Provides Hauling Out Space for Marine Mammals
The mammals that inhabit the ice in the Chukchi and Bering seas and
their adaptations to the pack ice environment were discussed by Fay
(1974). Many of these species frequently haul out on the ice, where
they provide food in the form of feces, placentas, and carcasses.
Sea Ice Provides Roosting Sites
Ice provides a hard substrate that allows seabirds to leave the
water to roost. This allows such species as the _Larus_ gulls, which
typically roost on hard substrates, to occur in large numbers well
offshore.
Sea Ice Reduces Wind Chill
The unevenness of the upper surface of the ice reduces the speed of
winds directly over the ice, thus providing a microhabitat and reducing
the amount of wind chill for birds sitting on and next to the ice.
Sea Ice Decreases Wave Action
Ice floating on the water reduces the surface disturbance of the
water. Although swells pass through areas with much ice cover, waves
do not. In addition, surface waters on the lee side of ice floes and
cakes usually have little surface disturbance. Surface feeders may be
able to locate prey more easily because of these reductions in surface
disturbance.
Specific Effects of Ice on Birds in the Western Arctic
The retreat of the pack ice each spring and the formation of new ice
each fall greatly affect a large area of the Arctic Ocean off the coast
of Alaska and much of the Bering Sea. Specific ways in which birds
are affected by ice in the western Arctic are discussed on a seasonal
basis. All observations are my own, unless otherwise stated.
Winter
Chukchi and Beaufort Seas
From late November to mid-April, ice cover of the Chukchi and Beaufort
seas is almost complete. The only areas where birds can be expected
to winter in these seas are the chronic lead systems. Such lead
systems are found off Wainwright and Point Barrow and south of the
Point Hope-Cape Thompson area (Shapiro and Burns 1975). Only the black
guillemot _(Cepphus grylle)_ is known to regularly winter offshore
from Wainwright and Point Barrow (Gabrielson and Lincoln 1959; Nelson
1969). In the Point Hope-Cape Thompson area, glaucous gulls _(Larus
hyperboreus)_, the common murre _(Uria aalge)_, and the thick-billed
murre _(U. lomvia)_ occur throughout the winter (Swartz 1967). It is
likely that black guillemots are also found in this area.
The lack of chronic lead systems in the Beaufort Sea precludes the
presence of wintering seabirds. The one species that may be found
wintering in the Beaufort is the Ross' gull _(Rhodostethia rosea)_.
Ross' gull is believed to winter primarily in the Arctic Ocean (Bailey
1948). The number of sightings that have been obtained in both the
eastern and western Arctic indicate that the species may winter over
much of the Arctic Ocean. It may thus be expected to occur in both the
Chukchi and Beaufort seas during winter.
Ice cover--not prey abundance--plays the major role in severely
limiting bird numbers in the Arctic Ocean in winter. Prey is known
to be abundant in parts of the Arctic Ocean during the period of
ice cover. In the Chukchi Sea, Eskimos fishing through the ice can
catch 23 kg of arctic cod per person per day (D.C. Foote, unpublished
data). Eskimos jig for the fish at considerable depths, and the cod
do not appear to be as common directly below the ice as they are in
summer. The effects of new ice (which forms on the underside of the
ice during the winter) on the under-ice fauna are not known. The
abundance of amphipods in ice-covered waters in winter is demonstrated
by the experience of the Greeley Expedition in the eastern arctic.
They discovered that any scrap of food thrown into a lead was quickly
consumed by amphipods. Nets were made to catch the amphipods and the
availability of this food source played a major part in the survival of
the expedition (Schmitt 1965).
Aside from the food found in leads in the ice, the only food available
to birds in the Beaufort and Chukchi seas in winter is carrion and the
feces of mammals found on the pack ice. The presence of the arctic
foxes on the pack ice during the winter demonstrates the availability
of scavenging opportunities on the ice. Arctic foxes on the pack ice
live on feces and the remains of seals killed by polar bears _(Ursus
maritimus)_. Polar bear and seals are both common in the Beaufort and
Chukchi seas in winter, but no scavenging seabirds are found there in
the winter. It was thought that the ivory gull _(Pagaphila eburnea)_
was associated with marine mammals during the winter, but they are now
known to winter at the Bering Sea ice edge, where they feed on fish and
crustaceans (Divoky 1976). The only birds associated with polar bear
kills in the Chukchi Sea in March are ravens, _Corvus corax_ (T. J.
Ely, Jr., personal communication).
Bering Sea
Ice begins to cover the northern Bering Sea in November and reaches its
maximum by February, when it usually extends as far south as the edge
of the continental shelf, and covers nearly 75% of the surface of the
Bering Sea (Lisityn 1969). Coverage can vary greatly from year to year.
In certain years Bristol Bay may be completely covered and in others
ice is found only in the northern part of the Bay. Almost all ice in
the Bering Sea is first-year ice. This ice tends to be flat on the top
and underside and in general lacks the extensive keels and pressure
ridges found on multi-year ice.
The Bering Sea ice has a number of large-scale features of importance
to birds. The "front" is a zone of ice south of the consolidated pack
that is composed of small floes, ice pans, and brash ice. This zone is
prevented from forming large floes by the action of swells from the
open water to the south. The front continually changes in width. When
winds are from the south, it is compressed into a narrow band; when
winds are from the north, it is a broad zone composed of bands of ice
interspersed with open water.
Polynias (areas of open water) are found immediately south of the large
islands in the northern Bering Sea. They are formed by the southward
movement of ice caused by the prevailing winds. This movement causes
ice to be pushed away from the south side of islands, leaving areas
of open water. Large polynias are associated with St. Lawrence, St.
Matthew, and Nunivak islands and with the south side of the Seward
Peninsula (Shapiro and Burns 1975).
The most biologically active area of the Bering Sea in winter is
the ice front. Studies of primary productivity in April show that
production at the surface in the ice front is high (1.98 mg C/m³
per h). Surface waters directly under the pack ice have much lower
production (0.29 mg C/m³ per h), and that in the water south of the
ice is lower yet. At this time production within the ice is very high
(more than 5 mg C/m³ per h) (McRoy and Goering 1974). Because this
phytoplankton bloom is trapped in the ice, it is not available to
grazers. Thus, before the spring melt the ice front is the only area
where a large quantity of phytoplankton is available to higher levels
of the marine food chain.
The winter distribution of birds in the Bering Sea correlates well with
the findings on primary productivity. Densities south of the ice and
the continental shelf average less than 10 birds/km². At the ice front
during one cruise in March, densities exceeded 500 birds/km². Densities
at the ice front increase from south to north; they drop in the region
where the ice front grades into more consolidated pack ice, and are
less than 0.1 bird/km² in the consolidated pack.
The most numerous species at the ice front are common and thick-billed
murres, which constitute more than 90% of all birds seen. Irving et
al. (1970) were the first to report on the large number of murres at
the ice front. Feeding flocks of 25,000 individuals have been observed
at the front, in which densities were as high as 10,000 birds/km². No
other diving species is common at the ice front. The parakeet auklet
_(Cyclorhynchus psittaculus)_ is seen on most cruises, but only during
a small percentage of observation periods and always in low numbers.
Black guillemots are common north of the ice front and stragglers
are occasionally seen at the front. Pigeon guillemots _(Cepphus
columbus)_, least auklets _(Aethia pusilla)_, and crested auklets _(A.
cristatella)_ are irregular visitors to the front.
Surface feeding species commonly found at the ice front include
the northern fulmar _(Fulmarus glacialis)_ and five species of
gulls. The fulmar is common south of the ice and is found only in
the southern portion of the front. Three species of _Larus_ are
found at the ice front. The most common is the glaucous-winged gull
_(Larus glaucescens)_; the glaucous gull is less frequently seen. The
slaty-backed gull _(L. schistisagus)_, a species that breeds in Asia,
is most common west of St. Matthew Island (McRoy et al. 1971). The
black-legged kittiwake _(Rissa tridactyla)_ is common in open water
south of the ice but is also found throughout the entire width of
the front. The ivory gull is unique in that it is found only at the
ice front in winter. In addition to these species, the fork-tailed
storm-petrel _(Oceanodroma furcata)_ is a regular but uncommon visitor
to the ice front in winter. Densities of surface feeding species at the
ice front are low when compared to the high densities of murres, and do
not regularly exceed 10 birds/km².
The primary food consumed by birds at the ice front is pollock
_(Theragra chalcogramma)_. An amphipod _(Parathemisto libellula)_ and
the euphausiids are less important. Examination of the stomach contents
of birds and fish show that large feeding flocks are usually associated
with schools of pollock feeding on _P. libellula_ and euphausiids.
The habitat of the consolidated pack in the Bering Sea is markedly
different from that at the ice front. Whereas the front is
characterized by bands of ice interspersed with open water and ice
coverage rarely exceeding 4 oktas (4/8), the consolidated pack consists
primarily of large expanses of unbroken ice. Small leads are formed
by the shifting of the ice caused by currents and wind. Ice coverage
is usually 7 to 8 oktas. The southern part of the consolidated pack,
which grades into the ice front, has frequent leads. Most of the
species found at the ice front can be found in the southern part of the
consolidated pack, but murres are most common. Their numbers decrease,
however, in the more northerly pack, where leads are less frequent.
Black guillemots, in contrast, increase with increasing ice cover, and
reach their greatest abundance in the small leads constantly forming
and refreezing deep within the ice. Because they exploit this habitat,
they are dependent on the formation of lead systems. I have often seen
leads a quarter mile wide refrozen to the point where new ice covered
all but a small patch of open water; black guillemots were frequently
crowded into this open water. Before the lead closes completely
the guillemots must fly to an open lead. When winds are light and
temperatures low, lead systems fail to form as rapidly as usual, and
when they do they refreeze quickly, causing a loss of the preferred
habitat of wintering black guillemots. A severe winter in the White Sea
in 1965-66 decreased the amount of open water and caused an increased
black guillemot mortality (Bianchi and Karpovitsch 1969). On a windless
day in March I conducted bird observations in the Bering Sea ice where
no leads or open water were encountered. The only bird seen was a black
guillemot flying over the ice. In situations such as this, where black
guillemots are prospecting for open water, they may use the "water sky"
and steam fog associated with leads as visual aids. "Water sky" is the
reflection of the dark water in the clouds over the lead, and contrasts
sharply with the "ice sky." The presence of "water sky" allows birds to
detect open water from a distance of many miles.
Aside from birds found in and near island-associated polynias, only
murres and black guillemots are regularly found on the consolidated
pack ice in winter.
The polynia associated with islands in the consolidated pack provide
refuge(s) for seabirds. Fay and Cade (1959) found the polynias south of
St. Lawrence to be most important to oldsquaws _(Clangula hyemalis)_.
King eiders _(Somateria spectabilis)_, common eiders _(S. mollisima)_,
and oldsquaws are common in the St. Matthew Island polynias (McRoy et
al. 1971). Because these polynias are in shallow-water areas, they
provide feeding opportunities for benthic feeding species.
_Spring_
Chukchi and Beaufort Seas
In April and May a lead system develops from the Bering Strait north
to Cape Lisburne and then northeast to Point Barrow. The lead is a
flaw lead that occurs between the shorefast ice and the free-floating
pack. It is a major migration route for a number of species of birds,
primarily eiders. East of Point Barrow in the Beaufort Sea, no similar
well-defined large lead exists. Consequently, there is a greater chance
of bird mortality occurring in the Beaufort Sea than in the Chukchi
Sea because the early migrants are unable to find open water. In 1960,
10% of all the king eiders that migrate through the Beaufort Sea
died during a late freeze (Barry 1968). Additional records of eider
mortality due to late breakup or sudden freezes were presented by
Palmer (1976).
In late May, rivers that empty into the northern Chukchi and Beaufort
seas begin to flow. The shorefast ice is still present at this time
and the rivers flow over the ice. For large rivers, such as the
Colville and the Sagavanirktok, the area of ice covered by water is
considerable. Openings in the ice develop sometime after the river
runoff starts and the river water drains through the ice.
This river overflow plays an important role in the breeding biology of
certain island nesting species, since the overflow surrounds islands
and prevents arctic foxes from reaching the islands. The overflow also
allows birds to sit in the water near breeding sites. It is not known
whether river overflow contains prey items available to birds. After
the overflow drains through the ice, the shorefast ice that has been
covered with river overflow decomposes quickly, and patches of open
water occur early in areas just seaward of major river deltas. For this
reason the largest breeding colonies on barrier islands in the northern
Chukchi and Beaufort seas are all found near the mouths of large
rivers. Islands away from rivers become isolated from the pack ice by
moats, which are caused by the absorption of solar radiation by the
islands and the melting of the ice immediately adjacent to them. Moat
formation is not as predictable and uniform as river overflow.
Bering Sea
When the ice in the Bering Sea begins to melt in April, the edge of the
pack does not recede northward as is frequently thought. Rather, there
is a general decomposition of ice throughout the pack. The leads that
are constantly forming in the ice no longer freeze. As melt continues
and ice becomes rotten, leads form with increasing frequency. This
manner of ice decomposition is important to birds. The leads that
form deep in the pack ice provide feeding and roosting areas near the
large seabird colonies found north of the ice edge, and are used by
certain tundra-nesting ocean migrants such as eiders, red phalaropes
_(Phalaropus fulicarius)_, and jaegers (_Stercorarius_ spp.). If
ice decomposition is retarded by persistent low temperatures, the
initiation of breeding may be delayed at northern Bering Sea colonies
and for some tundra species.
At the time of decomposition the large standing stock of phytoplankton
present in the pack ice is released into the water. No information is
available on fish and invertebrate populations that are associated
with the decomposing ice. The quantity of organic carbon released
is considerable, although it is not known what fish or invertebrate
populations are supported by this plankton as soon as it is released.
For birds breeding in areas where ice is present in the initial stages
of breeding, the phytoplankton released by the disintegrating ice could
play an important part in the birds' energy budgets.
_Summer_
Chukchi and Beaufort Seas
In the northern Chukchi and Beaufort seas the nearshore marine
environment is dominated by sea ice in June and July. In June the
coastal areas are characterized by a snow-free tundra teeming with
nesting waterfowl and shorebirds next to an expanse of sea ice almost
completely devoid of bird life. In areas where river outflow does not
occur, the use of nearshore waters usually begins when a moat forms
along the shoreline. Amphipods and other invertebrates are found in
this moat, especially at stream mouths. Limited but regular use of the
moat occurs, primarily by loons (_Gavia_ spp.), oldsquaws, and arctic
terns _(Sterna paradisaea)_.
As the snow on top of the shorefast ice begins to melt, ponds form on
top of the ice. As melt proceeds, these melt ponds merge into long,
parallel channels and may cover well over 50% of the ice surface. Only
when thaw holes form and the melt ponds are connected to the water
under the ice is food present in the channels. Amphipods are then
seen swimming in these channels. Bird use of these channels is not
extensive.
It is usually late July before the nearshore ice begins its rapid
decomposition. Ice in the lagoons is the first to melt. Ice seaward of
the barrier islands decomposes more slowly because of the presence of
keels and pressure ridges. As the ice melts, the in-ice algal bloom is
released into the water. These algae are important because they provide
at least 25 to 30% of the productivity in coastal waters and allow the
biological growing season to begin before the open-water plankton bloom
occurs (Alexander 1974). In nearshore areas close to Barrow, large
populations of mysids and amphipods are associated with the decomposing
ice. At least in certain areas, these ice-associated zooplankton
populations are a major food source for nearshore migrants, especially
red phalaropes, arctic terns, and Sabine's gulls _(Xema sabini)_.
The effects of ice scour on the shoreline and the nearshore bottom of
the Chukchi and Beaufort seas is demonstrated by the absence of sessile
benthic fauna and flora. The effect this absence has on birds is seen
in the feeding habits of nearshore birds. Oldsquaws and eiders, which
frequently feed on molluscs, feed instead on motile benthos species
such as mysids, amphipods, and isopods. The emperor goose _(Philacte
canagica)_ is absent from the northern Chukchi and Beaufort seas,
apparently due to the absence of eelgrass beds. Ice scour is the major
cause of the absence of eelgrass in northern Alaska (C. P. McRoy,
personal communication).
The offshore ice in the Chukchi decomposes more rapidly than that in
the Beaufort, largely because Bering Sea water enters the Chukchi
through the Bering Strait (Coachman and Barnes 1961). By late July the
Chukchi is usually ice free as far north as Icy Cape. In the Beaufort,
however, ice decomposition occurs slowly through June and July, and
only in August does a definite strip of open water develop between
the shore and the edge of the pack ice. The amount of open water
varies greatly from year to year. In certain years the Beaufort is not
navigable due to the lack of open water.
Aerial censusing in June and July shows that bird densities on the
offshore ice are extremely low. In August and September, when shipboard
censusing can be conducted, densities on the pack ice in both seas are
about 10 birds/km². Unlike the Bering Sea, where densities south of
the ice are much less than on the ice, bird densities south of the ice
in the Beaufort and Chukchi seas are slightly higher in the open water
south of the ice, averaging about 20 birds/km². In the Chukchi the
principal species encountered on the ice are the black-legged kittiwake
and the thick-billed murre. In the Beaufort, red phalaropes, oldsquaws,
and glaucous gulls are the most common species.
Numerous arctic cod are associated with the underside of the summer
pack ice. Shipboard censusing in the ice is complicated when cod are
stranded on ice floes, as the ice shifts under the weight of the ship.
Gulls, arctic terns, and jaegers gather behind the ship to feed on
these fish; mixed flocks of more than 100 birds are common. In the
absence of a ship to provide the disturbance needed to make large
numbers of cod available, these birds are dependent on locating the
fish in the surface waters next to ice floes. Because cod frequently
swim over underwater ice shelves they are highly visible from above and
should be easily accessible to aerial feeders.
_Fall_
Chukchi and Beaufort Seas
By the time ice formation begins in late September or early October,
most seabirds have left the Arctic on their southward migration. The
principal exception is the oldsquaw, which does not begin its migration
until September. Some oldsquaws remain in nearshore waters until they
are driven out by the formation of new ice. In contrast to the spring
mortality, there are few records of extensive bird mortality in the
fall due to lack of open water. One instance was reported for 1975,
when nearshore waters froze early and flightless eiders were seen
sitting on the ice near Pt. Lay in the Chukchi Sea. The birds were in
a weakened condition, apparently due to their inability to obtain food
(W. J. Wiseman, personal communication).
In the offshore waters the species associated with the pack ice in
September are the same as those in August. In late September, however,
ivory and Ross' gulls become the most common species at the ice edge in
the Chukchi. Glaucous gulls and black guillemots are also associated
with the advancing ice edge (Watson and Divoky 1972). Except for the
Ross' gull, which apparently winters in the arctic basin, these species
remain with the ice as it advances into the Bering Sea.
Bering Sea
Little is known about bird distribution in the Bering Sea during ice
formation because cruises in rapidly forming ice are potentially
hazardous. It is not known if the large numbers of birds found at the
ice edge in March are present in December and January.
Discussion
The principal effect of the arctic pack ice is to lower biological
productivity and bird densities in the areas it covers. Unlike the
antarctic pack ice, which supports a large biomass of pagophilic
species, the number of pagophilic species supported by the arctic pack
ice is small. Only the ivory gull, Ross' gull, and black guillemot
have specific adaptations to the ice environment. The Ross' gull and
guillemot winter in the pack ice, and the ivory gull is associated with
ice throughout the year. The total biomass of these species is low.
Other species which are regularly associated with the arctic pack, such
as murres and black-legged kittiwakes, are also found in large numbers
away from the ice. In addition, these species are usually associated
with ice for limited periods during the year--murres primarily in
winter and spring and kittiwakes primarily in summer.
The difference in the antarctic and arctic pack ice systems is largely
due to the antarctic pack ice being surrounded by ocean, whereas
the arctic pack ice is, in general, surrounded by land. The high
productivity associated with the antarctic pack ice is due primarily
to the mixing that occurs at the edge of the pack ice. There is little
opportunity for mixing to occur next to the arctic pack ice, except
where it is next to large expanses of boreal waters. This occurs in the
Bering Sea in winter and spring, in the North Atlantic, and to a minor
extent in the Chukchi Sea in summer and fall (Dunbar 1968). The limited
geographic range and seasonal nature of high productivity at the arctic
pack ice edge has been a major factor in preventing a well-developed
pagophilic avifauna.
The importance of the in-ice algal bloom and its associated under-ice
fauna is not yet clear. It is probably most important in areas such
as the Beaufort Sea, where productivity in the water column is low.
Although considerable numbers of seabirds are regularly found in the
summer pack ice feeding on arctic cod and zooplankton associated
with the ice, bird densities south of the ice are usually greater
than those in the ice. The only species that appear to depend on the
ice-associated fauna for much of their food are the three pagophilic
species mentioned above.
References
Alexander, V. 1974. Primary productivity regimes of the nearshore
Beaufort Sea, with reference to potential roles of ice biota.
Pages 609-632 _in_ J. C. Reed and J. E. Sater, eds. The coast and
shelf of the Beaufort Sea. Arctic Institute of North America,
Arlington, Virginia.
Andriashev, A. P. 1968. The problem of the life community
associated with the antarctic fast ice. Pages 147-155 _in_ R.
I. Currie, ed. Symposium on antarctic oceanography. Scott Polar
Research Institute, Cambridge.
Appollonio, S. 1961. The chlorophyll content of arctic sea ice.
Arctic 14:197-200.
Bailey, A. M. 1948. Birds of arctic Alaska. Colo. Mus. Nat. Hist.
Popular Ser. 8. 317 pp.
Barry, T. W. 1968. Observations on natural mortality and native
use of eider ducks along the Beaufort Sea coast. Can. Field-Nat.
82(2): 140-144.
Bianchi, V. V., and V. N. Karpovitsch. 1969. The influence of
abnormal ice-cover of the White Sea and Murman in 1966 upon
birds and mammals. (In Russian, English summary.) Zool. Zh.
48(6):871-875.
Bunt, J. S. 1963. Diatoms of antarctic sea ice as agents of primary
production. Nature (Lond.) 199:1255-1257.
Coachman, L. K., and C. A. Barnes. 1961. The contribution of Bering
Sea water to the Arctic Ocean. Arctic 15:147-161.
Divoky, G. J. 1976. The pelagic feeding habits of Ivory and Ross'
Gulls. Condor 78:85-90.
Dunbar, M. J. 1968. Ecological development in polar regions: a
study in evolution. Prentice-Hall, Englewood Cliffs, N.J. 119 pp.
Fay, F. H. 1974. The role of ice in the ecology of marine mammals
of the Bering Sea. Pages 383-399 _in_ D. W. Hood and E. J. Kelly,
eds. Oceanography of the Bering Sea. Univ. Alaska Inst. Mar. Sci.
Occas. Publ. 2.
Fay, F. H., and T. J. Cade. 1959. An ecological analysis of the
avifauna of St. Lawrence Island, Alaska. Univ. Calif. Publ. Zool.
63:73-150.
Gabrielson, I. N., and F. C. Lincoln. 1959. The birds of Alaska.
The Stackpole Company, Harrisburg, Pennsylvania, and Wildlife
Management Institute, Washington, D.C. 922 pp.
Irving, L., C. P. McRoy, and J. J. Burns. 1970. Birds observed
during a cruise in the ice-covered Bering Sea in March 1968.
Condor 72:110-112.
Lisityn, A. P. 1969. Recent sedimentation in the Bering Sea
(Transl. from Russian.) Israel Program for Scientific
Translations, Jerusalem. 614 pp.
McRoy, C. P., and S. R. Goering. 1974. The influence of ice on the
primary productivity of the Bering Sea. Pages 403-421 _in_ D. W.
Hood and E. J. Kelly, eds. Oceanography of the Bering Sea. Univ.
Alaska Inst. Mar. Sci. Occas. Publ. 2.
McRoy, C. P., S. W. Stoker, G. E. Hall, and E. Muktoyuk. 1971.
Winter observations of mammals and birds, St. Matthew Island.
Arctic 24:63-65.
Mohr, J. L., and S. R. Geiger. 1968. Arctic Basin faunal
precis-animals taken mainly from arctic drifting stations and
their significance for biogeography and water-mass recognition.
Pages 297-313 _in_ J. E. Sater, coordinator. Arctic drifting
stations. Arctic Institute of North America.
Nelson, R. K. 1969. Hunters of the northern ice. University of
Chicago Press, Chicago, Ill. 429 pp.
Palmer, R. S. 1976. Handbook of North American birds. Vol. 3. Yale
University Press, New Haven, Conn. 560 pp.
Schmitt, W. L. 1965. Crustaceans. University of Michigan Press, Ann
Arbor. 204 pp.
Shapiro, L. H., and J. J. Burns. 1975. Major late-winter features
of ice in northern Bering and Chukchi seas as determined from
satellite imagery. Univ. Alaska Geophys. Inst. Rep. 75-78.
Swartz, L. G. 1967. Distribution and movements of birds in the
Bering and Chukchi seas. Pacific Sci. 21:332-347.
Watson, G. E., and G. J. Divoky. 1972. Pelagic bird and mammal
observations in the eastern Chukchi Sea, early fall 1970. U.S.
Coast Guard Oceanogr. Rep. 50:111-172.
FOOTNOTES:
[1] Present address: Point Reyes Bird Observatory, 4990 State Route 1,
Stinson Beach, California 94970.
STATUS OF MARINE BIRD POPULATIONS
Distribution and Status of Marine Birds Breeding Along the Coasts of
the Chukchi and Bering Seas
by
James C. Bartonek[2]
U.S. Fish and Wildlife Service
Fairbanks, Alaska
and
Spencer G. Sealy
University of Manitoba
Winnipeg, Manitoba, Canada
Abstract
The Alaska coast fronting on the Chukchi
and Bering seas, exclusive of the Aleutian
Islands, supports seven complexes of marine
bird colonies numbering more than 1 million
birds each, nine colonies of 100,000 to almost
1 million birds, and many smaller colonies.
Colonies are found on most headlands and
islands and are dominated numerically by
alcids and kittiwakes (_Rissa_ sp.). Estuarine
habitats (mainly the lowlands of northern
Seward Peninsula, Yukon-Kuskokwim delta, and
the north side of the Alaska Peninsula) are
extremely important for breeding and migrating
marine waterfowl, shorebirds, gulls (_Larus_
sp.), and terns (_Sterna_ sp.). Information on
population size and distribution of breeding
marine birds within this area is extensive for
only a few of the more heavily hunted species
of waterfowl. Except for the intensive and
systematic censusing of a few colonies in this
region, population data on cliff-, burrow-, and
crevice-nesting birds are such that all but
gross changes in numbers may go unnoticed, and
if noticed they could not be measured.
Habitats for breeding marine birds are found along much of the 4,100-km
coastline of Alaska that fronts on the Chukchi and Bering seas.
Seasonal sea ice and an extensive outer continental shelf are dominant
features that contribute to the productivity of these marine waters,
which sustain populations of fishes, birds, and mammals that are of
considerable and diverse values to man (Kelley and Hood 1974).
Our purpose in this paper is to describe the distribution, abundance,
and relative status of some of the nearly 100 species of marine birds
breeding within this region and the information base from which
the descriptions are derived. Although the selection is admittedly
arbitrary, we discuss mainly the colonial nesting species because they
are generally in greater jeopardy from lost breeding habitat and from
catastrophes than are the species that are widely dispersed or solitary
in nesting. Because we believe matters affecting the conservation of
marine birds will be geographically oriented, we discuss the status
and distribution of breeding birds on that basis, rather than by
the more traditional taxonomic approach. We use the terms "colony"
and "colonies" somewhat loosely and interchangeably to include any
aggregation of birds of the same or different species nesting in
proximity to each other, even those on the same island or headland,
although populations may be miles apart and occupy different kinds of
habitats. The nature of this paper and the scale of our maps do not
allow for detailed resolution of each colony's location (for the most
part this information is not available), but rather facilitates a
general impression of status.
Most place-names used by us are shown in Fig. 1; the others may be
located by referring to Orth's (1967) gazetteer on Alaska.
Information Base
There is no adequate catalog of marine bird colonies and other avian
habitats for the Bering-Chukchi region or for Alaska as a whole.
King and Lensink (1971) described the waterfowl populations and
major lowland habitats of the State and listed only a few of the
many colonies of cliff-nesting birds. LeResche and Hinman (1973)
identified a few additional colonies, provided fragmentary information
on composition and abundance at some of these sites, and delineated
areas of wetland habitats on maps in their statewide atlas on wildlife.
General and occasionally site-specific information on the location,
but rarely on population size and composition, of colonies can be
gleaned from the 321 species accounts presented by Gabrielson and
Lincoln (1959) and from the general works by Bent (1919, 1921, 1922,
1923, 1925, 1927, 1929), Dement'ev and Gladkov (1951), Dement'ev et al.
(1951, 1952), Palmer (1962), Fisher (1952), Tuck (1960), and others.
The birds on the Asiatic side of these waters, which are not treated in
this paper, were described by Portenko (1973).
Information on the status of waterfowl in the region is generally more
detailed than that for most other groups of birds because waterfowl
have been the object of systematic surveys since the late 1940's as
part of the continent-wide effort to manage populations for sport
hunting. Because the emphasis of these surveys has been directed toward
the species of ducks important to hunters in the "lower 48" States,
data are not adequate to measure changes in populations for most sea
ducks and marine geese nesting in this region. These surveys have,
however, enabled biologists to delineate waterfowl habitats and make
reasonable estimates of populations for some of the more abundant and
conspicuous species (King and Lensink 1971; U.S. Fish and Wildlife
Service [FWS] 1973_c_; U.S. National Park Service [NPS] 1973).
_Chukchi Sea Coast_
A disproportionate percentage of ornithological investigations in
arctic Alaska have centered about Barrow, where ornithologists were
attracted because of the propensity of vagrant birds to collect
there and because of the above average facilities, conveniences,
and transportation afforded first by the whaling station, then by
the military, and later by a research laboratory. Recent petroleum
development near Prudhoe Bay has resulted in a somewhat commensal
eastward shift in ornithological studies.
Bailey (1948), Gabrielson and Lincoln (1959), and Pitelka (1974)
reviewed much of the published information on arctic avifauna,
including that of the Chukchi coast. Selkregg [1975] mapped various
avian habitats, ascribed either relative or absolute values for the
population size of certain groups of birds, and included a selected
bibliography that did not entirely duplicate those provided by the
other reviewers. Watson and Divoky (1975) described the avifauna of
Alaska's Beaufort Sea coast, which is much the same as that of the
Chukchi coast from Point Barrow south to Cape Lisburne (both coasts are
of low relief).
Intensive studies near Barrow have done much to characterize the
behavior, productivity, and ecological requirements of calidridine
sandpipers (Pitelka 1959; Pitelka et al. 1974; Holmes 1970, 1971)
and, to partly explain the cyclical relationships between jaegers
(_Stercorarius_ spp.) and their prey (e.g., Pitelka et al. 1955; Maher
1974). Quantitative estimates of certain bird populations at Cape
Thompson (Swartz 1966; Williamson et al. 1966), Little Diomede (Kenyon
and Brooks 1960), and on the coastal lowlands of the Seward Peninsula
(King and Lensink 1971; U.S. NPS 1973), and for black guillemots
_(Cepphus grylle)_ throughout the region (Divoky et al. 1974) are among
the best data on status of marine birds for any locality in Alaska.
Grinnell (1900_a_) described the birds he observed in the Kotzebue
Sound area.
[Illustration: Fig. 1. Place-names in the region of the Chukchi and
Bering seas.]
Cursory aerial surveys conducted by J. C. Bartonek, J. G. King, and
D. R. Cline (U.S. FWS 1973_a_; U.S. NPS 1973; this paper) in 1972 and
1973 provided information on the location and relative size of most, if
not all, colonies of cliff-nesting marine birds between Point Barrow
and the Bering Strait, including those at Cape Lisburne, at Motherhood
Point, Nine-mile Point, Cape Deceit, Towalevic Point, Sullivan Bluff,
all on the northern base of the Seward Peninsula, and at Fairway
Rock. The relative size of populations of most species was probably
underestimated because the burrow-and crevice-nesting species were
largely unseen.
_Bering Sea_
Aside from work by Gabrielson and Lincoln (1959) and the early but
understandably incomplete accounts by Nelson (1883, 1887) and Turner
(1886), no comprehensive description of the avifauna of the Alaskan
coast of the Bering Sea exists. Many studies adequately describe local
avifauna, and some of them are exemplary assessments of the status of
populations.
Most of the coastline suitable for cliff-nesting marine birds and most
of the smaller nearshore islands from the Bering Strait south to the
tip of the Alaska Peninsula were reconnoitered piecemeal from aircraft
between 1970 and 1973 by J. C. Bartonek, J. G. King, D. R. Cline, C. D.
Evans, and M. L. Plenert (U.S. FWS 1973_a_, 1973_b_; this paper). In
late June 1973 Bartonek, Cline, and Plenert made brief reconnaissances
on foot of King, Besboro, and Shaiak islands. Bartonek and J. G.
Divoky, traveling by boat and occasionally on foot, reconnoitered
colonies at Cape Seniavin, a portion of the Walrus Islands group,
Shaiak Island, and the coastline from Cape Peirce around Cape Newenham
to Security Cove (U.S. FWS 1973_a_, 1973_b_; this paper). Although
these cursory surveys (especially those from aircraft) tended to
identify nesting sites of cliff-nesting birds while missing sites used
by burrow-and crevice-nesting species, information was obtained on the
location and relative size of many previously unreported colonies.
The mainland and island colonies in Norton Sound have received little
notice in the published literature. Bailey (1943, 1948), although
working mainly at Little Diomede and in Arctic and Lopp lagoons on
the north side of the Seward Peninsula, mentioned the birds at Wales
Mountain and Tin City. Nelson (1883, 1887) traveled throughout the
region studying the avifauna and the anthropology of Eskimos. Grinnell
(1900_b_) at Nome, McGregor (1902) along the Koyuk River, Hersey (1917)
and Turner (1886) near St. Michael, and Cade (1952) at Sledge Island
provide fragmentary examples of the area's marine bird populations.
Colonies at King, Besboro, Egg, and Sledge islands, near York
Mountains, and at Bluff were described in proposals for new National
Wildlife Refuges (U.S. FWS 1973_a_).
Sealy et al. (1971) reviewed the literature and discussed the various
zoogeographic relationships among the avifauna of St. Lawrence Island.
Fay and Cade (1959) estimated numbers and biomass of all birds on St.
Lawrence Island but did not identify locations and sizes of particular
populations; consequently, replication of their estimates is precluded.
An exemplary study by Bédard (1969) identified the locations and
sizes of all populations of crested auklets _(Aethia cristatella)_,
least auklets _(A. pusilla)_, and parakeet auklets _(Cyclorrhynchus
psittacula)_ on the island. Sealy (1973) identified breeding sites of
horned puffins _(Fratercula corniculata)_ there and throughout the
species' range. Thompson (1967) listed the birds observed at Northeast
Cape and on nearby Punuk Islands.
Annotated accounts have been published on the breeding avifauna of St.
Matthew, Hall, and Pinnacle islands by Elliott (1882), Hanna (1917),
Bent (1919), and Gabrielson and Lincoln (1959). Klein (1959) presented
quantitative data on the birds he observed incidental to his study of
reindeer _(Rangifer tarandus)_.
The avifauna of the Yukon-Kuskokwim delta, which is rich both in
numbers and diversity, has been treated extensively in the literature.
Nelson (1883, 1887), Turner (1886), Conover (1926), Brandt (1943),
Gabrielson and Lincoln (1959), Williamson (1957), Kessel et al.
(1964), Harris (1966), Dau (1972), and Holmes and Black (1973) all
described the avifauna in the same general area of the delta, i.e.,
the eroding portion in the general vicinity of Hooper and Hazen bays.
The avifauna of the aggrading portion of the Yukon delta and of the
Kuskokwim's mouth have not been accorded similar attention. Populations
of waterfowl nesting on the delta and their wintering affinities were
described by King and Lensink (1971) and U.S. FWS (1973_c_).
Studies of particular species of marine birds on the delta (again, all
in the general vicinity of Hooper and Hazen bays) were reported by
Hansen and Nelson (1957) and Shepherd (1960) for black brant _(Branta
bernicla)_, by Headley (1967) and Eisenhauer and Kirkpatrick (1977) for
emperor geese _(Anser canagica)_, by Dau (1974) and Mickelson (1975)
for spectacled eiders _(Somateria fischeri)_, by Petersen (1976) for
red-throated loons _(Gavia stellata)_, and by Holmes (1970, 1971, 1972)
for dunlins _(Calidris alpina)_ and western sandpipers _(C. mauri)_.
Birds of Nunivak Island were reported by Swarth (1934), but the
importance of the island to marine birds was not put into proper
perspective until the Nunivak National Wildlife Refuge was evaluated
for designation as a wilderness area (U.S. FWS 1972).
The Pribilof Islands have served as a focal point for ornithological
investigations of the Bering Sea in much the same way that Barrow
has for the Arctic. The avifauna of the Pribilofs has been described
by Coues (1874), Elliott (1882), Palmer (1899), Hanna (1918), Preble
and McAtee (1923), Gabrielson and Lincoln (1959), Kenyon and Phillips
(1965), and a host of others that mainly added new species to the
record list. Although most of these ornithologists marveled at the
numbers of birds, information is lacking from which most changes in
populations can be noted. (An exception is the record of common and
thick-billed murres, _Uria aalge_ and _U. lomvia_, which formerly
nested in such abundance on Walrus Island that annually several tons of
eggs were gathered for consumption by residents of the islands [Palmer
1899], but were greatly reduced in numbers by the summer of 1973, when
J. C. Bartonek, J. G. King, G. J. Divoky, and D. T. Montgomery observed
only a few thousand murres on a small portion of the island. Most
of the suitable nesting sites, especially the flat areas often used
by common murres, were occupied by Steller's sea lions, _Eumetopias
jubata_, which, apparently because of reduced hunting pressure,
occupied the island and displaced the murres.)
For some unexplained reason the numerous and large marine bird colonies
along the north side of Bristol Bay appear to have been largely
overlooked until recent years (Bartonek and Gibson 1972). Gabrielson
and Lincoln (1959) summarized the few observations by Osgood (1904)
and Turner (1886) in this area, but obviously were unaware that, in
aggregate, these colonies rival those of the Pribilofs. Dick and Dick
(1971) made an exemplary study of marine birds and their numbers
at Cape Peirce and on nearby Shaiak Island. Murie (1959) provided
annotated remarks on marine birds of Amak Island, but not of nearby
Sealion Rocks.
Status and Distribution
Seven groups of colonies of cliff-, burrow-, and crevice-nesting birds
are found on the headlands and islands in the coastal region, each
numbering more than 1 million birds; nine colonies range downward to
100,000 birds; and a host of others range downward to 1,000 birds (Fig.
2). Un-estimated numbers of other marine birds nest on the lowlands
about Kotzebue Sound, the Yukon-Kuskokwim delta, and Bristol Bay, but
are not shown in Fig. 2. The occurrence at colonies of 20 of the nearly
100 species of marine birds is shown in Fig. 3; their relative numbers
at these sites are not shown because data are generally lacking.
[Illustration: Fig. 2. Relative numbers of marine birds at colonies in
different localities, without regard to species composition or breeding
status.]
[Illustration: Fig. 3. Location of known breeding populations of some
marine bird species without regard to size of population.]
[Illustration]
_Chukchi Sea_
The largest colonies of seabirds in the Chukchi Sea are those on Little
Diomede Island, Cape Lisburne, Cape Thompson, and Fairway Rock. Smaller
colonies are in Kotzebue Sound along the northern base of the Seward
Peninsula. These colonies are largely dominated by thick-billed and
common murres and black-legged kittiwakes _(Rissa tridactyla)_ and on
the islands in the Bering Strait also the crested, least, and parakeet
auklets. Horned puffins, tufted puffins _(Lunda cirrhata)_, pelagic
cormorants _(Phalacrocorax pelagicus)_, and glaucous gulls _(Larus
hyperboreus)_ make up the remaining majority. For the whole area there
are probably fewer than a hundred birds each of black guillemots and
pigeon guillemots _(Cepphus columba)_ occupying colonies. Dovekies
_(Alle alle)_ are occasionally sighted in this area, but only as
stragglers from their normal range.
Part of the mystery surrounding the nesting location of Kittlitz's
murrelet _(Brachyramphus brevirostris)_ was solved when Thompson et al.
(1966) discovered a downy chick in the Kukpuk River drainage nearly
45 km by river from salt water. Other nesting sites of the Kittlitz's
murrelets in this region were reported for Wales Mountain (Ford 1936;
Bailey 1943, 1948) and the Cold Bay area (Bailey 1973) (Fig. 3).
Only the colonies at Cape Thompson have been censused systematically
throughout a breeding season. During one of three years of varying
census efforts, Swartz (1966) estimated that about 400,000 birds of
nine species occupied the cliffs. Whereas the Cape Thompson colonies
received considerable attention because of Swartz's efforts, the
colonies that extend along nearly 35 km of headlands southward from,
but mainly at, Cape Lisburne have received little if any attention
by either early or recent ornithologists in the Arctic, even though
they support perhaps twice the number of birds. Also perplexing is why
Chamisso and Puffin islands with their several thousand nesting horned
puffins and lesser numbers of other seabirds were designated as the
Chamisso National Wildlife Refuge in the early 1900's when none of the
many larger and more species-diverse colonies in the area received
comparable recognition by and protection through refuge designation.
The lowlands on the north side of the Seward Peninsula produce
fall flights of sea ducks that average 49,200 oldsquaws _(Clangula
hyemalis)_, 51,000 eiders (mostly common eiders, _Somateria
mollissima_), and 26,700 scoters (mostly black scoters, _Melanitta
nigra_) (King and Lensink 1971). Small populations of black brant and
emperor geese breed in what outwardly appears to be excellent habitat,
and King and Lensink (1971) speculated that subsistence hunting by
local Eskimos is responsible for suppressing these populations.
_Bering Sea_
The largest concentration of nesting seabirds in the Bering Sea and
perhaps in the entire North Pacific is that on St. George Island.
Colonies that rank somewhere below that at St. George are along the
coast from Cape Newenham to Cape Peirce, in the Walrus Islands (Round,
High, Crooked, and Summit islands, The Twins, and Black Rock), at Cape
Mohican on Nunivak Island, St. Matthew Island, Southwest Cape of St.
Lawrence Island, and King Island.
The Pribilofs have the unique distinction of being the primary nesting
site of red-legged kittiwakes _(Rissa brevirostris)_. They are also
interesting from the zoogeographic standpoint in that they are the
northernmost stronghold of red-faced cormorants _(Phalacrocorax
urile)_; guillemots are conspicuous by their absence, and larid gulls
are conspicuously scarce nesters.
St. Matthew Island and associated Hall and Pinnacle islands, and all
but Walrus Island of the Pribilofs, are sites of nesting northern
fulmars _(Fulmarus glacialis)_. Nesting fork-tailed or Leach's
storm-petrels (_Oceanodroma furcata_ and _O. leucorhoa_) have been
found nowhere in this region, although both are commonly observed at
sea and both nest throughout the Aleutians.
Most colony sites identified in Fig. 2 are dominated by common or
thick-billed murres (or both) and black-legged kittiwakes. Glaucous
gulls (generally north of the Yukon-Kuskokwim delta), glaucous-winged
gulls _(Larus glaucescens)_ (generally to the south of the delta),
and pelagic cormorants occupy almost every rocky prominence along the
entire coast (most of these sites are not shown in Figs. 2 and 3).
Double-crested cormorants _(Phalacrocorax auritus)_ nest at a few
island and inland locations in the Bristol Bay area. The small auklets
are largely restricted to islands in the Bering Sea; the parakeet
auklet is the only one occasionally found in mainland colonies.
The marine birds of the Yukon-Kuskokwim delta lowlands, although
largely uncounted, in their aggregate probably exceed the numbers at
any individual site identified in Fig. 2. This is not particularly
surprising since the delta has nearly 70,000 km² of habitat (King and
Lensink 1971) in contrast to the generally small parcels of habitat
occupied at the sea-cliff and island sites.
King and Lensink (1971) estimated that fall flights of sea ducks
originating on the delta averaged 292,300 oldsquaws, 51,000 eiders
(mostly common and spectacled eiders with lesser numbers of Steller's
eiders, _Polysticta stelleri_), and 157,000 scoters (primarily black
scoters). They also estimated that half of the 150,000 black brant and
most of the 150,000 emperor geese in Alaska's fall flight originate
there. Although no counts have been made, we believe that the delta's
lowlands support easily more than half of Alaska's nesting dunlins,
black turnstones _(Arenaria melanocephala)_, rock sandpipers _(Calidris
ptilocnemis)_, western sandpipers, and substantial percentages of red
phalaropes _(Phalaropus fulicarius)_, northern phalaropes _(Lobipes
lobatus)_, and red-throated loons.
The north side of the Alaska Peninsula (including the wetlands,
uplands, and estuaries) is perhaps more important to marine birds as
a staging, feeding, and resting area than as a nesting habitat. The
importance of Izembek Lagoon to black brant and emperor geese during
fall and spring is a classic example. King and Lensink (1971) estimated
that the fall flight of sea ducks originating from the Peninsula
averages 53,400 oldsquaws, 1,700 eiders, and 74,400 scoters. Breeding
geese are scarce throughout the area.
Conclusions and Recommendations
Most of the major breeding habitats of marine birds in the Chukchi
and Bering seas are known, but imprecisely identified as to location
and size. With few exceptions, the populations of birds using these
habitats are described only by the subjective and ambiguous descriptors
of abundance such as "abundant, common, occasional, and rare," which
makes measurement of change impossible.
We recommend that first and foremost a catalog of habitats used by
birds be developed to aid resource administrators, developers, and
biologists (all of whom should be "conservationists") in identifying
critical habitats. We believe that such a catalog would preclude many
problems because birds and their habitats could be considered at the
planning stage rather than only at the operational stage. Such a
catalog would also be useful to students of ornithology who are seeking
locations suitable for particular studies.
Nowhere in this region have studies of marine birds been of sufficient
duration to enable changes in populations (from whatever cause) to
be characterized. Since some species of marine bird are known not to
breed before at least 3 or more years of age, meaningful information
on survival and recruitment in populations cannot be obtained by
studies of less than 10 years. We therefore recommend that long-term
studies be initiated at as many places as possible, but at least at
one site on the Yukon-Kuskokwim delta; at a mainland colony site that
has predominantly murres, kittiwakes, puffins, and cormorants; and
at an island site that also has small auklets. Although the nesting
distribution of the Kittlitz's murrelet remains an enigma, we regard it
less of a conservation issue and more of an ornithological challenge.
Consideration of logistics and support facilities must, of course, be
included in the site selection process. Most of the areas suggested for
these studies also merit recognition and protection by being designated
as a National Wildlife Refuge, a National Park or Monument, or a State
Game Sanctuary.
References
Bailey, A. M. 1943. The birds of Cape Prince of Wales, Alaska.
Proc. Colo. Mus. Nat. Hist. 18. 113 pp.
Bailey, A. M. 1948. Birds of arctic Alaska. Colo. Mus. Nat. Hist.
Popular Ser. 8. 317 pp.
Bailey, E. P. 1973. Discovery of a Kittlitz's murrelet nest. Condor
75(4):457.
Bartonek, J. C., and D. D Gibson. 1972. Summer distribution of
pelagic birds in Bristol Bay, Alaska. Condor 74(4):416-422.
Bédard, J. 1969. The nesting of the least, crested, and parakeet
auklets around St. Lawrence Island, Alaska. Can. J. Zool.
47(5):1025-1050.
Bent, A. C. 1919. Life histories of North American diving birds.
U.S. Natl. Mus. Bull. 107. 245 pp.
Bent, A. C. 1921. Life histories of North American gulls and terns.
U.S. Natl. Mus. Bull. 113. 345 pp.
Bent, A. C. 1922. Life histories of North American petrels,
pelicans, and their allies. U.S. Natl. Mus. Bull. 121. 343 pp.
Bent, A. C. 1923. Life histories of North American wild fowl. Part
I. U.S. Natl. Mus. Bull. 126. 250 pp.
Bent, A. C. 1925. Life histories of North American wild fowl. Part
II. U.S. Natl. Mus. Bull. 130. 311 pp.
Bent, A. C. 1927. Life histories of North American shore birds.
Part I. U.S. Natl. Mus. Bull. 142. 359 pp.
Bent, A. C. 1929. Life histories of North American shore birds.
Part II. U.S. Natl. Mus. Bull. 146. 340 pp.
Brandt, H. 1943. Alaska bird trails. Bird Research Foundation,
Cleveland, Ohio. 464 pp.
Cade, T. J. 1952. Note on the birds of Sledge Island, Bering Sea,
Alaska. Condor 52(1):51-54.
Conover, H. B. 1926. Game birds of the Hooper Bay region, Alaska.
Auk 43(2):162-180, 43(3):308-318.
Coues, E. 1874. Ornithology of the Prybilov Islands. Pages 168-212
_in_ H. W. Elliott, Report on the Prybilov Group, or Seal Islands
of Alaska. U.S. Treasury Department, Washington, D.C.
Dau, C. 1972. Observations on the spring migration of birds at
Old Kashunuk Village, Alaska. Univ. Alaska, Dep. Wildl. Fish.,
Fairbanks. 54 pp. (Unpublished report)
Dau, C. 1974. Nesting biology of the spectacled eider _Somateria
fischeri_ (Brandt) on the Yukon-Kuskokwim delta, Alaska. M. S.
Thesis. Univ. of Alaska, Fairbanks. 72 pp.
Dement'ev, G. P., and N. A. Gladkov. 1951. Birds of the Soviet
Union. Vol. 1. (Transl. from Russian.) Israel Progr. Sci.
Transl., 1966. 705 pp.
Dement'ev, G. P., N. A. Gladkov, Yu. A. Isakov, N. N. Kartashev, S.
V. Kirikov, A. V. Mikheev, and E. S. Prushenko. 1952. Birds of
the Soviet Union. Vol. 4. (Transl. from Russian.) Israel Progr.
Sci. Transl., 1967. 683 pp.
Dement'ev, G. P., N. A. Gladkov, and E. P. Spageburg. 1951. Birds
of the Soviet Union. Vol. 2. (Transl. from Russian.) Israel
Progr. Sci. Transl., 1968. 553 pp.
Dick, M. H., and L. S. Dick. 1971. The natural history of Cape
Peirce and Nanvak Bay, Cape Newenham Natl. Wildl. Refuge, Alaska.
U.S. Bureau Sport Fisheries and Wildlife, Bethel, Alaska. 78 pp.
Divoky, G. J., G. E. Watson, and J. C. Bartonek. 1974. Breeding of
the black guillemot in northern Alaska. Condor 76(3):339-343.
Eisenhauer, D. I., and C. M. Kirkpatrick. 1977. Ecology of the
emperor goose in Alaska. Wildl. Monogr. 57. 62 pp.
Elliott, H. W. 1882. Seal-islands of Alaska. U.S. Comm. Fish Fish.
Spec. Bull. 176, Sect. IX, Monogr. A. 176 pp.
Fay, F. H., and T. J. Cade. 1959. An ecological analysis of the
avifauna of St. Lawrence Island, Alaska. Univ. Calif. Publ. Zool.
63:73-150.
Fisher, J. 1952. The fulmar. N. M. N. Collins, London. 496 pp.
Ford, E. R. 1936. Kittlitz's murrelet breeding at Wales, Alaska.
Auk 51:214-215.
Gabrielson, I. N., and F. C. Lincoln. 1959. The birds of Alaska.
The Stackpole Co., Harrisburg, Pennsylvania, and Wildlife
Management Institute of North America, Washington, D.C. 992 pp.
Grinnell, J. 1900_a_. Birds of the Kotzebue Sound region, Alaska.
Pac. Coast Avifauna 1. 80 pp.
Grinnell, J. 1900_b_. Notes on some birds of Cape Nome, Alaska.
Condor 2(5):112-115.
Hanna, G. D. 1917. The summer birds of the St. Matthew Island Bird
Reservation. Auk 34(4):403-410.
Hanna, G. D. 1918. Check list of birds of the Pribilof Islands,
Alaska, with names of persons first recording the species from
the islands. Pages 105-107 _in_ W. T. Bower, ed., Report of U.S.
Commissioner of Fisheries. Bureau of Fisheries Document 872.
Hansen, H. A., and U. C. Nelson. 1957. Brant of the Bering
Sea--migration and mortality. Trans. N. Am. Wildl. Nat. Resour.
Conf. 22:237-256.
Harris, S. W. 1966. Summer birds of the lower Kashunuk River,
Yukon-Kuskokwim delta, Alaska. Murrelet 47(3):57-65.
Headley, P. C. 1967. Waterfowl. Ecology of the emperor goose.
Alaska Dep. Fish Game Small Furbearer Invest. 8:1-25.
Hersey, F. S. 1917. The present abundance of birds in the vicinity
of Fort St. Michael, Alaska. Auk 34(2):147-159.
Holmes, R. T. 1970. Differences in population density,
territoriality, and food supply of dunlin on arctic and subarctic
tundra. Pages 303-319 _in_ A. Watson, ed., Animal populations in
relation to their food resources. Br. Ecol. Soc. Symp. 10.
Holmes, R. T. 1971. Density habitat and mating system of the
western sandpiper _(Calidris mauri)_. Oecologia 7(2):191-208.
Holmes, R. T. 1972. Ecological factors influencing the breeding
season schedule of western sandpipers _(Calidris mauri)_ in
sub-arctic Alaska. Am. Midl. Nat. 87(2):472-491.
Holmes, R. T., and C. P. Black. 1973. Ecological distribution
of birds in the Kolomak River-Askinuk Mountain region,
Yukon-Kuskokwim delta, Alaska. Condor 75(2):150-163.
Kelley, E. J., and D. W. Hood, eds. 1974. PROBES: a prospectus on
processes and resources of the Bering Sea shelf, 1975-1985. Univ.
Alaska, Inst. Mar. Sci. Publ. Inf. Bull. 75-1. 71 pp.
Kenyon, K. W., and J. W. Brooks. 1960. Birds of Little Diomede
Island, Alaska. Condor 62(6):457-463.
Kenyon, K. W., and R. E. Phillips. 1965. Birds from the Pribilof
Islands and vicinity. Auk 82(4):624-635.
Kessel, B., H. K. Springer, and C. M. White. 1964. June birds
of the Kolomak River, Yukon-Kuskokwim delta, Alaska. Murrelet
45(3):37-47.
King, J. G., and C. J. Lensink. 1971. An evaluation of Alaskan
habitat for migratory birds. U.S. Bur. Sport Fish. Wildl.,
Washington, D.C. 46 pp. (Unpublished administrative report)
Klein, D. R. 1959. Saint Matthew Island reindeer-range study. U.S.
Fish Wildl. Serv., Spec. Sci. Rep.--Wildl. 43. 48 pp.
LeResche, R. E., and R. A. Hinman, eds. 1973. Alaska's wildlife and
habitat. Alaska Department of Fish Game, Juneau. 144 pp. + 564
maps.
Maher, W. J. 1974. Ecology of pomarine, parasitic, and long-tailed
jaegers in northern Alaska. Pac. Coast Avivauna 37. 148 pp.
McGregor, R. C. 1902. A list of birds collected in Norton Sound,
Alaska. Condor 4(6):135-144.
Mickelson, P. G. 1975. Breeding biology of cackling geese and
associated species on the Yukon-Kuskokwim delta, Alaska. Wildl.
Monogr. 45. 35 pp.
Murie, O. J. 1959. Fauna of the Aleutian Islands and Alaska
Peninsula. U.S. Fish Wildl. Serv., N. Am. Fauna 61:1-364.
Nelson, E. W. 1883. Birds of the Bering Sea and Arctic Ocean. Pages
44-120 _in_ Cruise of the Revenue-steamer Corwin in Alaska and
the N. W. Arctic Ocean. U.S. Treas. Dep. Doc. 429.
Nelson, E. W. 1887. Report on natural history collections made in
Alaska between the years 1877 and 1881. U.S. Army, Signal Serv.
Arct. Ser. Publ. 3. 337 pp.
Orth, D. J. 1967. Dictionary of Alaska place names. U.S. Geol.
Surv. Prof. Pap. 567. 1084 pp.
Osgood, W. H. 1904. A biological reconnaissance of the base of the
Alaska Peninsula. U.S. Dep. Agric., Div. Biol. Surv., N. Am.
Fauna 24:9-86.
Palmer, R. S., ed. 1962. Handbook of North American birds. Vol. 1.
Loons through flamingos. Yale Univ. Press, New Haven, Conn. 567
pp.
Palmer, W. 1899. The avifauna of the Pribilof Islands. Pages
355-431 _in_ D. S. Jordan, ed. The fur seals and Fur Seal Islands
of the North Pacific, Part III. U.S. Treasury Department,
Commercial Fur-seal Investigations, Washington, D.C.
Petersen, M. R. 1976. Breeding biology of arctic and red-throated
loons. M. S. Thesis. Univ. of California, Davis. 55 pp.
Pitelka, F. A. 1959. Numbers, breeding schedules, and
territoriality in pectoral sandpipers of northern Alaska. Condor
61(4):233-264.
Pitelka, F. A. 1974. An avifaunal review for the Barrow region and
North Slope of Alaska. Arct. Alp. Res. 6(2):161-184.
Pitelka, F. A., R. T. Holmes, and S. F. MacLean, Jr. 1974. Ecology
and evolution of social organization in arctic sandpipers. Am.
Zool. 14:185-204.
Pitelka, F. A., P. Q. Tomich, and G. W. Treichel. 1955. Ecological
relations of jaegers and owls near Barrow, Alaska. Condor 57(1):
3-18.
Portenko, L. A. 1973. The birds of the Chukotsk Peninsula
and Wrangel Island. Acad. Sci. S.S.S.R., Zool. Inst., Sci.
Publishers, Leningrad. 2 vols. [In Russian.]
Preble, E. A., and W. L. McAtee. 1923. A biological survey of the
Pribilof Islands, Alaska. Part I. Birds and mammals. U.S. Bur.
Biol. Surv., N. Am. Fauna 46:1-128.
Sealy, S. G. 1973. Breeding biology of the horned puffin on St.
Lawrence Island, Bering Sea, with zoogeographical notes on the
North Pacific puffins. Pac. Sci. 27:99-119.
Sealy, S. G., F. H. Fay, J. Bédard, and M. D. F. Udvardy. 1971. New
records and zoogeographical notes on the birds of St. Lawrence
Island, Bering Sea. Condor 73(3):322-336.
Selkregg, L. L., ed. [1975]. Alaska regional profiles: Arctic
region. Univ. Alaska, Arct. Environ. Inf. Data Cent., Anchorage.
218 pp.
Shepherd, P. E. K. 1960. Production and abundance of the
black brant in Alaska. Alaska Dep. Fish Game, Game Div.
Pittman-Robertson Proj. Rep. 2(8):58-77.
Swarth, H. S. 1934. Birds on Nunivak Island, Alaska. Pac. Coast
Avifauna 22. 64 pp.
Swartz, L. G. 1966. Sea-cliff birds. Pages 611-678 _in_ N. J.
Wilimovsky and J. N. Wolfe, eds. Environment of the Cape Thompson
region, Alaska. U.S. AEC, Div. Tech. Inf., Oak Ridge, Tennessee.
Thompson, C. F. 1967. Notes on the birds of the Northeast Cape of
St. Lawrence Island and of the Punuk Islands, Alaska. Condor
69(4):411-419.
Thompson, M. C., J. Q. Hines, and F. S. L. Williamson. 1966.
Discovery of the downy young of Kittlitz's murrelet. Auk
83(3):349-351.
Tuck, L. 1960. The murres. Can. Wildl. Serv. Ser. 1. 260 pp.
Turner, L. M. 1886. Contributions to the natural history of Alaska.
U.S. Army, Signal Serv. Arct. Ser. Publ. 2. 226 pp.
U.S. Fish and Wildlife Service. 1972. Nunivak National Wildlife
Refuge wilderness study report. Agency, Anchorage, Alaska. 200 pp.
U.S. Fish and Wildlife Service, Alaska Planning Group. 1973_a_.
Proposed Alaska Coastal Refuges, Alaska. Agency Draft Environ.
Statement 73-94. 247 pp. + appendixes.
U.S. Fish and Wildlife Service, Alaska Planning Group. 1973_b_.
Proposed Togiak National Wildlife Refuge. Agency Draft Environ.
Statement 73-100. 183 pp. + appendixes.
U.S. Fish and Wildlife Service, Alaska Planning Group. 1973_c_.
Proposed Yukon Delta National Wildlife Refuge, Alaska. Agency
Draft Environ. Statement 73-101. 205 pp. + appendixes.
U.S. National Park Service, Alaska Planning Group. 1973. Proposed
Chukchi-Imuruk National Wildlands, Alaska. Agency Draft Environ.
Statement 73-84. 306 pp. + appendixes.
Watson, G. E., and G. J. Divoky. 1975. Marine birds in the Beaufort
Sea. Pages 681-695 _in_ J. C. Reed and J. E. Sater, eds. The
coast and shelf of the Beaufort Sea. Arctic Institute of North
America, Washington, D.C.
Williamson, F. S. L. 1957. Ecological distribution of birds in
the Napaskiak area of the Kuskokwim River delta, Alaska. Condor
59(5):317-338.
Williamson, F. S. L., M. C. Thompson, and J. Q. Hines. 1966.
Avifaunal investigations. Pages 437-480 _in_ N. J. Wilimovsky
and J. N. Wolfe, eds. Environment of the Cape Thompson region,
Alaska. U.S. AEC, Div. Tech. Inf., Oak Ridge, Tennessee. 1250 pp.
FOOTNOTES:
[2] Present address: U.S. Fish and Wildlife Service, 500 NE Multnomah
Street, Portland, Oregon 97232.
Breeding Distribution and Status of Marine Birds in the Aleutian
Islands, Alaska
by
Palmer C. Sekora[3]
U.S. Fish and Wildlife Service
Kailua, Hawaii
G. Vernon Byrd[4]
U.S. Fish and Wildlife Service
Adak, Alaska
and
Daniel D. Gibson
_University of Alaska
Fairbanks, Alaska_
Abstract
Seabird population estimates are generally
lacking for the 1,800-km-long Aleutian Islands.
Only the locations of the larger colonies are
known, and for these there are only imprecise
estimates of colony sizes and often even of
species composition. Changes in the status of
several species and populations resulting from
geologic and marine actions and from human
intrusions are evident. Accounts are given for
25 species of marine birds breeding in these
islands.
The 1,800-km-long chain of islands known as the Aleutians provides
nesting habitat for various species of marine birds, including three
species of Procellariiformes and three of cormorants (_Phalacrocorax_
spp.), one species of gull _(Larus glaucescens)_, both kittiwake
species (_Rissa_ spp.), two species of terns (_Sterna_ spp.), and at
least 13 species of alcids.
Seabird population estimates of known accuracy are lacking for this
isolated area. Locations of larger colonies of breeding seabirds are
known, however, and sufficient data are available to place colonies
in broad size ranges. Published information on the breeding biology
of marine birds is also lacking from the Aleutians, but some studies
are under way. The distribution of nesting marine birds away from the
nesting cliffs is totally unknown.
Introduced predators, primarily arctic foxes _(Alopex lagopus)_, are
now found on nearly every island. Breeding marine bird populations
have suffered drastic reductions as a result. They have probably also
changed because of natural habitat modifications caused by earthquakes,
volcanic eruptions, tidal waves, and marine erosion.
The purpose of this paper is to summarize the known present
distribution and status of breeding marine birds in the Aleutian
Islands.
Description of the Aleutian Islands
The Aleutian Islands form an arc that separates the Bering Sea and
the north Pacific Ocean (Fig. 1). The island chain extends from the
tip of the Alaska Peninsula to within 483 km of the Commander Islands
of Siberia. The chain contains more than 200 islands--the peaks of a
submarine volcanic mountain range. Volcanic activity and earthquakes
occur regularly.
Weather is characterized by perpetual overcast, dense summer fog,
high-velocity winds, and mild temperatures with low annual and diurnal
variations. The sea is ice-free year-round except in extremely cold
winters, when the arctic ice pack may reach the extreme northern
islands.
The Aleutians are treeless except for a few introduced, stunted
spruces. Woody shrubs are restricted to the most northern islands on
each end of the Chain. Mosses, lichens, club mosses, and heaths are
common ground-cover plants, and taller grasses, sedges, and umbellifers
constitute the overstory. Hulten (1960) provided a list of terrestrial
plants found in the Aleutians. Amundsen and Clebsch (1971) discussed
terrestrial plant ecology at Amchitka, central Aleutians. The marine
plant communities around the islands are fairly diverse. Lebednik et
al. (1971) described marine algal communities at Amchitka.
The easternmost Aleutian island, Unimak, has a mammalian fauna like
that of the Alaska Peninsula, including brown bear _(Ursus arctos)_,
caribou _(Rangifer tarandus)_, wolf _(Canis lupus)_, and wolverine
_(Gulo gulo)_. West of Unimak, red foxes _(Vulpes fulva)_ occurred
historically as far as Umnak, and arctic foxes were apparently on Attu
when the Russians came in 1741 (Murie 1959). Except for man and dog, no
land mammals occurred between Umnak and Aggatu islands. Arctic foxes,
introduced before 1930 for fur farming, still roam almost every island.
Norway rats _(Rattus norvegicus)_ were introduced on many islands when
ships were wrecked or as a result of military activities during World
War II.
Sea otters _(Enhydra lutris)_ have repopulated most of the Aleutians
after being nearly extirpated by 1900. Rookeries of Steller's sea lion
_(Eumetopias jubata)_ are scattered throughout the Aleutians during
summer, and numerous harbor seals _(Phoca vitulina)_ haul out on
beaches and offshore rocks.
All five species of Pacific salmon (_Oncorhynchus_ spp.) occur near the
islands, and at least four of them (all but _O. tshawytscha_) spawn in
Aleutian streams. Dolly Varden _(Salvelinus malma)_ and three-spine
sticklebacks _(Gasterosteus aculeatus)_ are found nearly everywhere
there is fresh water. The marine environment provides habitat used by
at least 77 species of fish (Isakson et al. 1971). O'Clair and Chew
(1971) furnished a recent reference to littoral macrofauna at Amchitka.
About 200 species of birds have been recorded in the Aleutians
(Aleutian Islands National Wildlife Refuge, unpublished data). Many of
these are windblown stragglers from both North America and Asia; only
59 species breed on the islands. Although seabirds make up less than
half (26 species or 44%) of the breeding birds, they may compose more
than 90% of the breeding avian biomass.
Ornithological Investigations in the Aleutians
Published ornithological information from the Aleutian Islands is
relatively scarce. G. W. Steller, naturalist on Vitus Bering's 1741
expedition to Alaska, was the first person to record ornithological
information in the islands (Stejneger 1936). More than a century passed
before W. H. Dall (1873, 1874) published the next papers dealing with
birds in the Aleutians. In 1878, the U.S. Army Signal Corps sent L.
M. Turner to the Aleutians to set up weather stations at several
locations. Turner kept notes on birds at various locations in the
Aleutians and published two papers (1885, 1886) on his observations.
Turner's data (1886) provided the first report based on extended and
widespread observations in the area. E. W. Nelson, who replaced Turner,
also provided data on birds (Nelson 1887).
In 1906, A. C. Bent came to the Aleutians specifically to look for
birds, and he and Alexander Wetmore recorded birds throughout the
island chain (Bent 1912). A. H. Clark (1910) provided a valuable
record of his observations in the Near Islands. All these workers
recorded birds in several locations, but none provided data on more
than a very few seabird colonies.
[Illustration: =Fig. 1.= The Aleutian Islands.]
O. J. Murie, U.S. Biological Survey, made the most complete survey of
the Aleutians (Murie 1959). He specifically recorded seabird colonies,
spending parts of four summers in the area. Murie visited every
large Aleutian island and most small ones. He recorded nearly every
major colony of cliff-nesting or talus-nesting seabirds known in the
Aleutians, but seldom gave sizes of colonies, and separate colonies on
a particular island were often not differentiated.
World War II brought several ornithologists to the Aleutians. Cahn
(1947), Sutton and Wilson (1946), Taber (1946), and Wilson (1948)
provided accounts of birds observed at specific locations. After the
war, Fish and Wildlife Service personnel--including I. N. Gabrielson
(Gabrielson and Lincoln 1959), K. W. Kenyon (Kenyon 1961), and R. D.
Jones (Refuge Narrative Reports 1949-1970)--recorded observations of
breeding seabirds at several locations in the Aleutians. Investigations
associated with Atomic Energy Commission nuclear testing at Amchitka
Island provided the first ecological study of avifauna of an Aleutian
island (White et al. 1977). Byrd et al. (1974) provided a list of birds
at Adak.
In 1971, the Near Islands were surveyed by U.S. Fish and Wildlife
personnel in a Cape Cod dory. In 1972, the Aleutian Islands National
Wildlife Refuge obtained a vessel, the _Aleutian Tern_, which allowed
visits to all parts of the island chain. That year, nearly every large
island as far west as Buldir was visited, and seabird colonies were
mapped. Every island has been visited at least once since 1972.
Methods
In estimating the current status of seabirds in the Aleutians, all
available data were considered. Most of the information used, however,
is from surveys conducted by the U.S. Fish and Wildlife Service
(1970-75, unpublished data). Because these surveys only incidentally
included Unimak, Akun, Akutan, Unalaska, and Umnak islands, data for
these areas are almost totally lacking. Data for Bogoslof, Adak,
Amchitka, Buldir, Agattu, Nizki, Alaid, and Attu are most accurate
because fairly intensive investigations have been conducted there since
1970.
The available data are of unknown accuracy. The method used by most
investigators who have surveyed areas in the Aleutians for seabird
colonies has been to circle islands in a ship or small boat; when a
colony was encountered, they simply estimated the number of birds they
saw at the time. The accuracy of the estimates is affected by weather,
distance from the colony, density of birds, ability and experience
of the observer, and other variables. Estimates of kittiwakes and
cormorants should be the most accurate, since nests were actually
counted. Murres (_Uria_ spp.) are readily visible on the cliffs, but
the percentage of breeders on the cliffs at a particular time of day
during a particular part of the breeding season is not known. Auklet
numbers are perhaps hardest to estimate, since swirling "clouds" of
birds are encountered.
Even when the estimates of birds seen are assumed to be accurate, data
interpretation is complex. Lack of information on diurnal rhythms adds
difficulty to data interpretation. Counts of burrow-nesting birds
(e.g., puffins) have been inaccurately interpreted because of the
lack of understanding of their nesting ecology. Gulls (_Larus_ spp.),
terns, and jaegers (_Stercorarius_ spp.) are not well known since
shore parties have seldom investigated island interiors. Nocturnal
species (e.g., ancient murrelet, _Synthliboramphus antiquus_, and
storm-petrels, _Oceanodroma_ spp.) are perhaps the least known. Since
only crude estimates of colony sizes are available, broad limits are
used in this paper to describe known colonies.
Status and Distribution of Breeding Seabirds
Even from the sparse literature available, it is apparent that some
seabird populations are now drastically different from those in the
Aleutians around 1900. Changes in nesting habitat due to volcanic
eruptions, tidal waves, marine erosion, and earthquakes have occurred
for centuries, and colonial nesting bird populations have fluctuated
accordingly. In addition, native Aleuts used marine birds and their
eggs for food and their skins for clothing, but the Aleuts were so
diminished in numbers by 1900 that they have had little recent effect
on the bird populations.
From about 1900 to 1936, arctic foxes were introduced to most of the
Aleutians for fur farming. The foxes lived on birds in summer, and some
species (e.g., Aleutian Canada geese, _Branta canadensis leucopareia_)
were wiped out wherever foxes were introduced. Ground-nesting and some
burrow-nesting seabirds were also drastically reduced or extirpated on
many islands.
During World War II the thousands of troops in the Aleutians brought
dogs and cats to some of the islands as pets, and many of the animals
were set free when the men departed. The military also accidentally
introduced Norway rats to some of the islands. Their role in seabird
population reductions is unknown.
Figures 2-15 (pages 40-46) present data on the distribution of
populations of birds that have survived the foxes and other introduced
predators. An annotated list of seabirds breeding in the Aleutians
follows.
_Annotated List of Species_
Northern fulmar _(Fulmarus glacialis)_
Northern fulmars breed on only three islands: Buldir (200 pairs),
Gareloi (1,500 pairs), and Chagulak (more than 100,000 pairs). Fulmars
were apparently much more widespread formerly (Murie 1959; Turner
1886). Introduced foxes were probably involved in the decline.
Fork-tailed Storm-petrel and Leach's Storm-petrel (_Oceanodroma
furcata_ and _O. leucorhoa_)
The distribution of storm-petrels is poorly known due to their
nocturnal behavior near the nesting colonies. The presence of birds
has generally been noted by finding them aboard ships anchored near
islands after darkness. Population estimates are not available for
any colonies, so symbols used in Fig. 3 indicate probable numbers of
breeding birds. In few cases have active burrows or crevices been
discovered. Storm-petrels were formerly much more common. Murie (1959)
and John L. Trapp (personal communication) found large numbers of
storm-petrel remains in fox dens. Most present breeding colonies are
probably confined to offshore islets and fox-free islands.
Double-crested Cormorant, Pelagic Cormorant, and Red-faced Cormorant
(_Phalacrocorax auritus_, _P. pelagicus_, and _P. urile_)
Double-crested cormorants breed as far west as the Islands of Four
Mountains. The colonies vary in size from a few to 25 pairs. Pelagic
and red-faced cormorants nest from Amak to Attu on nearly every
island. Relative abundance of the two in mixed colonies varies between
areas as well as from year to year. Red-faced cormorants tend to
nest in colonies mixed with kittiwakes and murres, but pure colonies
also occur. Pelagic cormorants occupy isolated, small colonies, but
they also nest with kittiwakes and murres and are often found with
red-faced cormorants. By far the densest concentration of cormorants
occurs in the Near Islands, especially at Attu, where an estimated
77,000 birds were seen in 1970. In the Aleutians as a whole, red-faced
cormorants outnumber pelagic cormorants, and double-crested cormorants
make up only a very small percentage of the breeding population.
Parasitic Jaeger _(Stercorarius parasiticus)_
The distribution of jaegers is poorly known because investigators have
spent little time ashore on most islands. Murie (1959) found jaegers on
a number of islands, and most of the data in Fig. 5 are his. Population
estimates are available only for Amchitka (25 pairs; White et al. 1977)
and Buldir (30-40 pairs; G. V. Byrd, unpublished data).
Glaucous-winged Gull _(Larus glaucescens)_
Glaucous-winged gulls no longer nest on islands where foxes occur
except where islands in lakes are available. Most colonies are on
offshore rocks or islets and range in size from a few pairs to over 200
pairs, and occasionally more. They are found throughout the Aleutians,
but the largest known colonies are at Bogoslof (500 pairs) and Buldir
(250 pairs).
Black-legged Kittiwake and Red-legged Kittiwake (_Rissa tridactyla_ and
_R. brevirostris_)
Black-legged kittiwakes breed locally in every major island group,
usually mixed with murres and cormorants. The large colonies contain
over 25,000 birds, but colonies of less than 50 pairs also occur.
Red-legged kittiwakes breed only on Buldir and Bogoslof. They are
remnants of a previously more widespread population.
Arctic Tern and Aleutian Tern (_Sterna paradisaea_ and _S. aleutica_)
Terns breed locally in each island group. Both species occur at Attu,
Amchitka, Adak, and Umnak, but only arctic terns are found at Nizki.
Factors limiting distribution are unknown. Colonies vary in size from
less than 10 pairs to 100 pairs.
Common Murre and Thick-billed Murre (_Uria aalge_ and _U. lomvia_)
Like kittiwakes, murres are abundant locally. A pure colony of either
species is almost unknown, although one species often makes up more
than 90% of a colony. Common murres may have been reduced by foxes,
since they tend to use sites with less slope than those used by
thick-billed murres. At Bogoslof and the Baby islands, the birds use
inland, gently sloping areas because there are no foxes. The presence
of the lichen _(Caloplaca spp.)_, which according to Tuck (1960) is
indicative of bird roosts, on several extensive cliff areas suggests
that either murres or kittiwakes, or both, formerly used areas they do
not use now.
Pigeon Guillemot _(Cepphus columba)_
This species has been noted near almost every island that has been
visited. Nesting under beach boulders and driftwood, the birds only
occasionally are found in large concentrations (near Great Sitkin more
than 4,000 birds were seen in 1971). Murie et al. (1937) summed up
the distribution of pigeon guillemot accurately: "Each island has its
meager quota of these birds, nesting unobtrusively among the rocks but
never assembled in any really large groups." Estimates of populations
may be extremely inaccurate because the diurnal rhythm of the pigeon
guillemot is unknown.
Marbled Murrelet and Kittlitz's Murrelet (_Brachyramphus marmoratus_
and _B. brevirostris_)
Nests of neither species have been located in the Aleutians, but
nesting of both is suspected at Adak, Unalaska, and Unimak, where
specimens of Kittlitz's with brood patches or eggs in the oviduct have
been collected in nearshore waters. Courtship has been recorded in
marbled murrelets (Byrd et al. 1974).
Ancient Murrelet _(Synthliboramphus antiquus)_
The distribution of this species is very poorly known, since it is
nocturnal near nesting colonies. Murie (1959) wrote, "This is one of
the species that undoubtedly has greatly declined in recent years, as
a result of increase of the blue-fox industry." The leading of downy
young to sea by the adults is a very noisy process and foxes could
easily take large numbers. Also, these murrelets nest in fairly shallow
burrows which foxes could dig out easily. Birds were recorded near
islands in every group during surveys from 1972 to 1975, but workers
seldom went ashore to determine if they were nesting. In Fig. 12, the
only basis for designating most of the areas marked as colonies is the
presence of birds during breeding season (15 May-1 July).
Cassin's Auklet _(Ptychoramphus aleuticus)_
This is another species that was more common before the fox was
introduced. Cassin's auklet now seems to occur only locally, but these
nocturnal birds are probably often overlooked. They are known only from
Buldir, Umnak, and the vicinity of Oglodak.
Parakeet Auklet _(Cyclorrhynchus psittacula)_
This auklet, which nests under beach boulders, in burrows, and in rock
crevices, seems to use a greater variety of breeding sites than do
the other auklets. The largest known colony is at Chagulak, where an
estimated 10,000 were seen in 1972. Smaller colonies are found as far
west as Buldir.
Crested Auklet, Least Auklet, and Whiskered Auklet (_Aethia
cristatella_, _A. pusilla_, and _A. pygmaea_)
_Aethia_ nest primarily in rock crevices of talus slides. Such habitat
occurs locally in each major island group except the Near Islands.
Least auklets outnumber crested auklets in the Aleutians, and whiskered
auklets are far less common than either. Estimates of populations
are probably grossly inaccurate because of the difficulty both in
estimating the number of birds in the milling flocks observed and in
interpreting the estimates after they are obtained.
Horned Puffin and Tufted Puffin (_Fratercula corniculata_ and _Lunda
cirrhata_)
Horned puffins favor rock crevices in talus slides and cliff faces
for nesting, whereas tufted puffins are primarily burrow nesters.
The historical distribution of the two species was probably based on
availability of nesting sites, so tufted puffins were more widespread
and numerous. However, in areas where extensive talus slopes are
available, horned puffins reached high densities. Predation by
introduced foxes may have altered the distribution of tufted puffins,
which now nest primarily on fox-free islets just offshore from the
larger islands where foxes occur. The distribution of horned puffins
may not have been altered significantly, since they are relatively free
from fox predation in their rock crevices.
Recommendations
A complete survey of the Aleutian Islands has not been done. This
should be done, by methods that will provide accurate population
estimates. Life history information is needed on almost all species,
and data should be gathered on selected populations to determine
trends. Information on winter distribution should also be compiled. The
effects of introduced predators should be evaluated quantitatively, and
if control measures are needed, effective, humane methods should be
devised and implemented.
Acknowledgments
The authors are grateful to the following Fish and Wildlife Service
personnel who helped collect previously unpublished data used in this
paper: E. P. Bailey, C. S. Craighead, C. P. Dau, M. H. Dick, G. J.
Divoky, R. Martin, J. L. Trapp, G. W. Watson, and C. M. White. Most of
the data were collected from the deck of the Aleutian Islands National
Wildlife Refuge research vessel _Aleutian Tern_. Captain George Putney
is acknowledged for his peerless seamanship and constant encouragement;
he also contributed observations of birds.
The maps were adapted from a master supplied by Elaine Rhode, Public
Affairs Office, U.S. Fish and Wildlife Service, Anchorage; she also
suggested the use of squares to display data. C. M. White graciously
made his in-press manuscript available. W. B. Emison, R. J. Gordon,
and J. L. Trapp kindly made their field notes available, and Trapp
helped compile data. Most of the funds for the surveys in 1971-75 were
provided by the U.S. Fish and Wildlife Service.
References
Amundsen, C. C., and E. E. C. Clebsch. 1971. Dynamics of the
terrestrial ecosystem vegetation of Amchitka Island, Alaska.
Bioscience 21:619-623.
Bent, A. C. 1912. Notes on birds observed during a brief visit to
the Aleutian Islands and Bering Sea in 1911. Smithsonian Misc.
Coll. 56(2):1-29.
Byrd, G. V., D. D. Gibson, and D. L. Johnson. 1974. The birds of
Adak Island, Alaska. Condor 76:288-300.
Cahn, A. R. 1947. Notes on the birds of the Dutch Harbor area of
the Aleutian Islands. Condor 49:78-82.
Clark, A. H. 1910. The birds collected and observed during the
cruise of the United States Fisheries steamer "Albatross" in
the north Pacific Ocean and in the Bering, Okhotsk, Japan, and
Eastern seas from April to December 1906. Proc. U.S. Natl. Mus.
38:25-74.
Dall, W. H. 1873. Notes on the avifauna of the Aleutian Islands,
from Unalaska eastward. Proc. Calif. Acad. Sci. 5:25-35.
Dall, W. H. 1874. Notes on the avifauna of the Aleutian Islands,
especially those west of Unalaska. Proc. Calif. Acad. Sci.
5:270-281.
Gabrielson, I. N., and F. C. Lincoln. 1959. The birds of Alaska.
The Stackpole Co., Harrisburg, Penn., and Wildlife Management
Institute, Washington, D.C. 922 pp.
Hulten, E. 1960. Flora of the Aleutian Islands. J. Kramer,
Weinham/Bergstr., Sweden. 376 pp.
Isakson, J. S., C. A. Sinensted, and R. L. Burgner. 1971. Fish
communities and food chains in the Amchitka area. Bioscience
21:666-670.
Jones, R. D. 1949-1970. Annual refuge narrative reports, Aleutian
Islands N.W.R. Cold Bay, Alaska. (Unpublished administrative
report.)
Kenyon, K. W. 1961. Birds of Amchitka Island, Alaska. Auk
78:305-326.
Lebednik, P. A., F. C. Weinmann, and R. E. Norris. 1971. Spatial
and seasonal distributions of marine algal communities at
Amchitka Island, Alaska. Bioscience 21:656-660.
Murie, O. J. 1959. Fauna of the Aleutian Islands and Alaska
Peninsula. U.S. Fish Wildl. Serv., N. Am. Fauna 61. 364 pp.
Nelson, E. W. 1887. Report upon natural history collections made in
Alaska between the years 1877 and 1881. U.S. Army, Signal Serv.
Arct. Ser. Publ. 3. 337 pp.
O'Clair, C. E., and K. K. Chew. 1971. Transect studies of littoral
macrofauna, Amchitka Island, Alaska. Bioscience 21:661-664.
Stejneger, L. 1936. George Wilhelm Steller--the pioneer of Alaska
natural history. Harvard University Press, Cambridge, Mass. 623
pp.
Sutton, G. M., and R. S. Wilson. 1946. Notes on the winter birds of
Attu. Condor 48:83-91.
Taber, R. D. 1946. The winter birds of Adak, Alaska. Condor
48:272-277.
Tuck, L. M. 1960. The murres. Ottawa. Canadian Wildlife Series 1.
260 pp.
Turner, L. M. 1885. Notes on the birds of the Near Islands, Alaska.
Auk 2:154-159.
Turner, L. M. 1886. Contributions to the natural history of Alaska.
U.S. Army, Signal Serv. Arct. Ser. Publ. 2. 226 pp.
White, C. M., F. S. L. Williamson, and W. B. Emison. 1977.
Avifaunal investigations. Pages 227-260 _in_ M. L. Merritt and
R. G. Fuller, eds. Environments of Amchitka Island, Alaska. U.S.
Energy Research and Development Association, Oak Ridge, Tenn. 682
pp.
Wilson, R. S. 1948. The summer bird life of Attu. Condor 50:124-129.
[Illustration: Fig. 2. Breeding distribution of northern fulmar.]
[Illustration: Fig. 3. Breeding distribution of storm-petrels.]
[Illustration: Fig. 4. Breeding distribution of cormorants.]
[Illustration: Fig. 5. Breeding distribution of parasitic jaeger.]
[Illustration: Fig. 6. Breeding distribution of glaucous-winged gull.]
[Illustration: Fig. 7. Breeding distribution of kittiwakes.]
[Illustration: Fig. 8. Breeding distribution of terns.]
[Illustration: Fig. 9. Breeding distribution of murres.]
[Illustration: Fig. 10. Breeding distribution of pigeon guillemot.]
[Illustration: Fig. 11. Breeding distribution of marbled and Kittlitz's
murrelet.]
[Illustration: Fig. 12. Breeding distribution of ancient murrelet.]
[Illustration: Fig. 13. Breeding distribution of auklets.]
[Illustration: Fig. 14. Breeding distribution of horned puffin.]
[Illustration: Fig. 15. Breeding distribution of tufted puffin.]
FOOTNOTES:
[3] Present address: U.S. Fish and Wildlife Service, William L. Finley
National Wildlife Refuge, Route 2, Box 208, Corvallis, Oregon 97330.
[4] Present address: U.S. Fish and Wildlife Service, Kilauea, Hawaii.
The Historical Status of Nesting Seabirds of the Northern and Western
Gulf of Alaska
by
LeRoy W. Sowl
U.S. Fish and Wildlife Service
1011 East Tudor Road
Anchorage, Alaska 99507
Abstract
The history of ornithological field work in the
Gulf of Alaska dates back to 20 July 1741 and
Bering's discovery of Alaska. In spite of this
long history, the record is fragmentary and
often seemingly contradictory. The coming of
the tanker terminal at Valdez and the pending
development of oil and gas resources on the
outer continental shelf threaten massive change
for seabirds in the Gulf of Alaska. Often
overlooked, however, is the fact that man has
already effected a change in status for many
of these birds. In this paper I examine the
scanty, general record from the exploratory
period, roughly 1741 to 1935, and the somewhat
more comprehensive record of the reconnaissance
period, 1936-74, and attempt to develop a basis
for better understanding of the change in
seabird status that has already taken place.
This paper should be treated as a verbal model
which can be improved as our knowledge of
seabirds in the Gulf of Alaska is expanded.
From the perspective of history, 1970 should prove to have been
a momentous year for Alaska and its seabirds. Two events, the
construction of the Trans-Alaska Pipeline and the passage of the
National Environmental Policy Act (NEPA) merged head on in 1970 with
the decision that Section 2c of NEPA applied to the proposed pipeline.
The systematic appraisal of potential environmental impacts required
by Section 2c quickly exposed the inadequacy of the existing data base
in many areas. With respect to seabirds in the Gulf of Alaska, it was
apparent that there had never been any effort to develop a synthesis of
the information accumulated over 230 years. The data gaps which were
uncovered were appalling.
While the Trans-Alaska Pipeline impact statement had provided shock
therapy, it was not the only influential event on the horizon. Two
local disturbances had already preceded the pipeline. These were
Project Chariot at Cape Thompson and the Amchitka Island test program.
Now in quick succession the Wilderness Act and native land claims added
new urgency to the need for solid resource information. More recently,
the outer continental shelf minerals leasing program has made the quick
development of base-line information even more essential.
All of the new activity in Alaska's coastal waters has the potential
to affect seabirds in one way or another. We must remember, however,
that man's activities have been affecting seabirds for a long time. We
cannot accurately assess the effect of a tanker terminal at Valdez or
offshore oil activity without first developing some understanding of
the current status of seabirds in the context of the historical record.
Seabird work in Alaska can be divided roughly into three periods.
The first is the early historical or exploratory period; it extended
from Georg Steller's 1741 visit to Kayak Island to 1935. This was
literally a period of exploration and the collection of information
was dependent upon interest and opportunity. The second is the
reconnaissance period; during this period investigators were dispatched
to a particular area to gather general information for management
application. This period begins with Murie's extensive investigations
of the Alaska Peninsula and the Aleutian Islands; I see it extending
from 1936 to 1975. In 1975 the need for data became so acute that
it was necessary to enter the third period, one of intensive data
gathering. Knowing where the big seabird colonies were located and
knowing their general species composition was no longer adequate. The
current intensive data-gathering effort in the waters over oil and
gas leasing areas is a partial response to the recognition of this
inadequacy.
In this paper I draw some tentative conclusions relative to the status
of the 26 species of primary seabirds (Fisher and Lockley 1954)
breeding in, or which may have bred in, the northern and western Gulf
of Alaska area. This area extends from Cape Fairweather, 59°N 138°W,
westerly along the coast to Ikatan Bay, 55°N 163°W, at the end of the
Alaska Peninsula. These bird species tend to be colonial, but not
exclusively so. Two birds which are primary seabirds, the mew gull
_(Larus canus)_ and Bonaparte's gull _(L. philadelphia)_, have not been
included because they tend to be more riverine than marine in habit.
Several marine ducks have been excluded because they are secondary
seabirds.
Information from the early exploratory period is summarized under the
next section. The more detailed information from the reconnaissance
period is discussed in the species accounts.
Summary of the Historical Record
The history of ornithological field work in the Gulf of Alaska
goes back 235 years to 20 July 1741. On that day Bering's
surgeon/naturalist, Georg W. Steller, spent a scant 10 h ashore on
Kayak Island. He collected a single bird. This bird, later named for
Steller, reminded him of a plate of the blue jay by Make Catesby,
the colonial-era predecessor of Audubon, in Volume 1 of the _Natural
History of Carolina, Florida, and the Bahama Islands_ (Stejneger's
annotated translation of Steller's journal in Golder 1925). Collection
of the bird confirmed for Steller that the first Russian Expedition had
reached America.
Steller was an accomplished naturalist, but his overbearing and
superior manner had apparently sorely irritated Bering and his officers
long before the expedition reached Kayak Island. The seamen made little
effort to go ashore anywhere in Alaska and Steller was blocked from
doing so as well. In addition to Kayak Island, he was able to go ashore
only on Nagai Island, first with a water party on 30 August and again
the next day. He noted that "all sorts of waterbirds in abundance were
seen." These included two kinds of cormorants, auks, ducks, gulls,
divers, pigeon guillemots _(Cepphus columba)_, tufted puffins _(Lunda
cirrhata)_, and horned puffins _(Fratercula corniculata)_.
Stejneger's comment on the identity of the cormorants is interesting
because, based on his experience, he assumed them to be pelagic and
double-crested cormorants (_Phalacrocorax pelagicus_ and _P. auritus_).
He gave no thought to red-faced cormorants _(P. urile)_ which are now
common there.
Steller noted on 6 September off Bird Island in the Shumagin
Islands, that "when we were out to sea about half a mile we were
especially astonished at the untold numbers of seabirds which we
saw on the northern side of the island." These birds were listed as
cormorants, auks, horned puffins, fulmars _(Fulmarus glacialis)_,
pigeon guillemots, black oystercatchers _(Haematopus backmani)_,
and a pied diver which Stejneger assumed was an ancient murrelet
_(Synthliboramphus antiquus)_.
On 15 September when Bering's vessel, the _St. Peter_, was south of
Amukta Pass, Steller recorded observing "river gulls." The observation
is not as interesting as Stejneger's comment (Golder 1925) concerning
it. Stejneger stated that no true river gulls lived in the Aleutians
and these must, therefore, have been another small gull with red
feet. He thought they must have been the red-legged kittiwake _(Rissa
brevirostris)_, which "inhabits the Aleutian Islands from Bering Island
to Sannak."
Thirty-seven years after Bering's voyage, Captain James Cook sailed
into the Gulf of Alaska, arriving off Kayak Island on 11 May 1778.
Cook was not accompanied by an able naturalist. His surgeon, William
Anderson, did have some experience gained on earlier voyages in
preparing skins and taking notes, but he had contracted tuberculosis
and became so ill that even his notes ceased after 8 June, while the
expedition was in Cook Inlet.
Cook was under orders to keep a careful record of everything he saw.
One of the results was that he had birds collected even though he had
no naturalist to do the work. Several birds were collected in Prince
William Sound while Cook's vessels were at anchor in Port Etches.
These included two marbled murrelets (_Brachyramphus marmoratus_--type
specimens), a black oystercatcher, a surfbird _(Aphriza virgata)_, a
surf scoter _(Melanitta perspicillata)_, and a red-breasted merganser
(_Mergus serrator_--type specimen), along with several forest birds
(Stresemann 1949).
The watch journals of Cook and his officers provide some additional
information. Captain Charles Clerke (Beaglehole 1974) remarked in
his log on the passage out of Prince William Sound through Montague
Strait on 20 May that "it had almost become tautology to mention whales
and seals and innumerable sea fowl that so confoundingly kept their
distance."
Between the Trinity Islands and Chirikof Island on 18 June, Cook's men
collected a single tufted puffin. Later Cook passed close to the Semidi
Islands and the Shumagin Islands and directly through the Sandman
Reefs. Beaglehole's version of this part of the voyage makes no mention
of seabirds.
There is a gap of 87 years during which there is almost no hint of
published material bearing on the status of seabirds in the Gulf of
Alaska. In 1865 the Russo-American Telegraph Expedition touched this
area. Dall and Bannister (1869) provide us with a few scraps garnered
during that expedition, primarily by Bischoff. The glaucous-winged gull
_(Larus glaucescens)_ was described as the most common species from
California northward. Bischoff's collections at Kodiak indicate that
the horned and tufted puffins were collected with ease. He was able
also to collect an Aleutian tern (_Sterna aleutica_--type specimen)
along with an egg.
Dall (1873) noted in 1872 that the black-legged kittiwake _(Rissa
tridactyla)_ was common at Round Island and Delarof Harbor, Unga
Island, in the Shumagins. The inference is that it was more common at
these two places than elsewhere. The Arctic tern _(Sterna paradisaea)_
was abundant in the Shumagin Islands and particularly at Range Island
in Popoff Strait. Dall expressed the opinion that the horned puffin was
very abundant in the Shumagins and appeared to fill the niche of the
tufted puffin, which he did not see there. The only other bird which he
thought to be very common was the pigeon guillemot. He did not note the
common murre _(Uria aalge)_ at all.
In 1908 the second of three Alexander Expeditions conducted field work
in the Prince William Sound area. From Dixon (1908) and Grinnell (1910)
we can derive some basis for assessing status in a very general way.
The most common seabird noted was the marbled murrelet. Glaucous-winged
gulls and black-legged kittiwakes were common; the glaucous-winged
gull was the more common. Horned puffins were judged to be slightly
more common than tufted puffins by both authors. The northern end
of Montague Strait appears to have been the center of abundance for
puffins. Dixon noted that on 16 July 1908 there were swarms of puffins
in the channel along Green Island. Pigeon guillemots were common along
the rocky coasts. Parakeet auklets _(Cyclorrhyncus psittacula)_, common
murres, and ancient murrelets were noted only in very small numbers.
After the Alexander Expeditions there was another doldrum in which
little was done. During this lull in activity, a note by Townsend
(1913) appeared which compared the numbers of crested auklets _(Aethia
cristatella)_ at Yukon Harbor, Big Koniuji Island, to the least auklets
_(A. pusilla)_ of St. George Island, stating that the crested auklets
were more numerous. He sailed into the Yukon Harbor anchorage on the
evening of 1 August and observed that crested auklets "were present in
myriads. The surface of the water was covered with them, and the air
was filled with them."
The formal record available to researchers is very shallow for
this exploratory period. With a few exceptions it was compiled by
non-scientists, primarily explorers and egg and skin collectors.
Current Status
_Setting the Stage_
This paper should be viewed as a conceptual model. While I attempted
to be as objective as possible, subjectivity was unavoidable. Many
of the tentative conclusions are based on very little data. Each
improvement will make it a better management tool. Because of the space
limitations, it is not possible to go into a detailed tracking of my
reasoning for each species. In an attempt to overcome this handicap, I
am including some examples of the sorts of reasoning that went into the
process.
In 1973 I led a Fish and Wildlife Service (FWS) reconnaissance survey
team that was delineating seabird colonies along the Alaska Peninsula.
In the Shumagin Islands we entered or crossed Koniuji Strait twice
(on 11 and 12 June) without even suspecting the presence of a horned
puffin colony. A third passage through the strait (13 June) was not so
uneventful. The water and the air were filled with horned puffins. This
led to the discovery that the 430-m mountain on the southeastern corner
of Big Koniuji was also covered with horned puffins, clear to its top.
The minimum estimate of the birds that were visible was 140,000. Even
this number of birds would make this the largest horned puffin colony
ever discovered. David Spencer (personal communication) had noted
similar swarms of horned puffins in this strait in 1956 while flying
sea otter surveys in the area. In 1975 a field camp was established at
Yukon Harbor, with study of this colony as one of the prime objectives
of the investigators. As far as these investigators could tell no such
large colony existed there, even though the nesting habitat was still
there, unaltered. This sort of event, one of the banes and vagaries of
estimating seabird numbers, is not rare.
In 1973, when FWS personnel delineated the colony on the southwestern
end of Bird Island in the Shumagins, there were estimated to be 43,000
kittiwakes, 24,000 murres, and 6,000 cormorants present; no tufted
puffins were seen about the colony. The last time (in 1970) one of the
observers, Edgar Bailey, had visited the colony with Robert Jones,
there was an extremely large colony of tufted puffins which Jones (E.
Bailey, personal communication) estimated at more than 1 million birds.
We made a particular effort to visit Jude Island, between the Shumagin
Islands and the Pavlof Islands, because David Spencer (personal
communication) had reported once having seen the air over the island
filled with an extremely large number of tufted puffins. However, there
were no puffins at this colony either.
Let us examine the facts in context. On 8 June we had visited High
Island where we had attempted to collect puffin eggs for pesticide
analysis, but had been able to find only one egg. Also, there were
only 6,000 tufted puffins where George Putney, master/engineer of the
_Aleutian Tern_, had seen much larger numbers in 1972. These two facts
could easily be related to explain the current situation because it
was still early in the breeding season. The horned puffin observations
in Koniuji Strait (11-13 June) were in keeping with this conclusion
also--an indication that these birds had not yet settled down to a
full breeding effort. The erratic comings and goings of common puffins
_(Fratercula arctica)_ early in the season have been well documented
(Lockley 1962). It is an easy step to extend this reasoning to the
absence of birds at Bird Island on 11 June, even though fresh signs of
the characteristic evidence of tufted puffin occupancy were missing.
Jude Island provides a different clue, however. There were 3,000
pigeon guillemots, an unheard-of concentration, apparently occupying
abandoned tufted puffin burrows on 15 June. Also, on 7 June we had made
a very interesting observation that had no special significance at the
time: murres on Spitz Island were occupying little parapets created by
mashing down the mouths of puffin burrows which filled the slope above
the cliff portion of their colony.
After looking at all of the observations cited above, I conclude that
tufted puffins were greatly reduced in numbers on these sites in 1973
and that they had been absent from the burrows used by the murres and
pigeon guillemots for more than the current breeding season. What
causes these sorts of changes? I do not know.
One reason for year-to-year change may be local movements of colonies.
Black-legged kittiwakes nest at several places in lower Orca Inlet,
Prince William Sound. Counts made at these sites in 1972 and 1974
yielded almost identical totals but the numbers of birds varied
between individual sites. This may be an indication that all of these
sites are part of one large composite colony and that, at least in this
colony and for this species, the birds shift at will.
The best record of population flux involving two species has been
summarized by Peterson and Fisher (1955). In 1872 and 1873 the murres
observed on Walrus Island in the Pribilofs were almost entirely common
murres. In 1890 common and thick-billed murres _(Uria lomvia)_ were
evenly matched in number. By 1901 the colony was almost exclusively
dominated by thick-billed murres. In 1911 and 1914 the few thick-billed
murres present were almost lost among the then dominant common murres.
In 1940 thick-billed murres dominated again. When Peterson and
Fisher visited the island in 1953, the situation was again reversed
and common murres had almost completely replaced the thick-billed
murres. These changes are even more impressive because of the number
of birds involved, between 1 and 2 million in 1953. There are more
tenuous indications that somewhat the same thing may occur between
two other congener pairs, the pelagic and red-faced cormorants and
the black-legged and red-legged kittiwakes. The causative factor, or
factors, is not readily apparent. One possibility is long-term climatic
fluctuation.
Dement'ev and Gladkov (1966) provide an example of abrupt and massive
change. Before 1876, the pelagic cormorant abounded on the Commander
Islands. During the winter of 1876-77, the birds were decimated by an
unknown epizootic disease. By spring only a few individuals remained
alive. The record shows that by 1882 they were already becoming common
again. Red-faced cormorants were apparently not reduced in number
because Dement'ev and Gladkov (1966) state that they were common in
"the second half of the last century and the beginning of this." Did
they flourish only while the pelagic cormorants were reduced in number?
Bowles (1908) gives another indication of naturally induced population
impact. He noted large numbers of dead seabirds on Washington beaches
and the ocean "rather plentifully dotted with sick birds ..." He
examined some birds and found "many hundreds" of tapeworms in every
bird. His conclusion was that their intestines were so solidly packed
with tapeworms that starvation was "an absolute certainty."
Some apparent disruptions are long term. In the Gulf of Alaska there is
a hiatus in the distributions of a number of small seabirds that are
active around their colonies only at night. Repeatedly, the northern
Gulf of Alaska shows up as an area of reduced population, as a boundary
between subspecies, or as a limit to a range. This same area has a
noticeable lack of total darkness during a substantial portion of the
breeding season.
The nocturnal habit no doubt evolved because it was advantageous to
concentrate on the breeding grounds only under the cover of darkness,
when diurnal predators were at a great disadvantage. Cody (1973) states
that Cassin's auklet _(Ptychoramphus aleuticus)_, which is strictly
nocturnal around its colonies, avoids these colonies on brightly
moonlit nights. He sees this as an apparent response to gull predation.
At higher latitudes the small alcids have overcome this disadvantage by
swamping predators through their sheer numbers. In the Gulf of Alaska I
suspect that few of the small seabirds, except possibly the fork-tailed
storm-petrel _(Oceanodroma furcata)_, have ever achieved great enough
numbers to offset the impact of extended daylight.
Past disruptions of seabird populations are both natural and
man-induced; however, the documentary record is much too fragmentary to
allow us to fully appreciate what has occurred or what the long-term
effect has been. To give some perspective to the problems associated
with assessing change and attempting to understand it, some of the
indicators of natural and unnatural change and flux in seabird
populations are reviewed here.
The flux in bird numbers can be related to the time of day, season of
the year, and atmospheric conditions on a short-term basis. This sort
of flux or apparent flux can easily be explained. The underlying cause
of some of the longer term flux is not so easily arrived at. Murie
(1959), Gabrielson and Lincoln (1959), and Sowl and Bartonek (1974)
have noted some of the man-induced changes. These are also explored to
some extent in the species accounts as they are found to apply.
I sometimes refer to a colony size class when discussing the existing
data rather than to an actual population estimate. The size classes
used are defined as follows:
Class I--less than 100 birds
Class II--100-1,000
Class III--1,000-10,000
Class IV--10,000-100,000
Class V--100,000-1,000,000
Class VI--more than 1,000,000
The _Dictionary of Alaska Place Names_ (Orth 1967) is the reference for
those who wish to locate some of the less obvious sites. The _Coast
Pilot, No. 9_ (U.S. Department of Commerce 1964) is another useful
reference.
_Species Accounts_
Northern Fulmar _(Fulmarus glacialis)_
Petrels of a number of species can be found in the Gulf of Alaska, some
of them in great numbers. Only the northern fulmar breeds there.
The fulmar is common in the offshore waters of the northern Gulf of
Alaska throughout most of the year (Isleib and Kessel 1973). Most
authors, including Clark (1911), one of the earlier ones, who commented
on the distribution of fulmars farther out in the Gulf, have considered
them to be abundant. Nichols (1927) raised one of the few voices of
apparent dissent; he noted that in 1926 he encountered the largest
number of fulmars (about 800) on 11 July in Shelikof Strait after he
had left the Gulf. During the summer, fulmars are very common seaward
of Montague Island, particularly to the northeast of Patton Bay and in
the approaches to Montague Strait. Data derived from FWS surveys in
July and August 1972 showed an estimated 10,000 fulmars in a stretch of
waters 19 km wide along the east side of Montague Island (Isleib and
Kessel 1973).
Over the Portlock Banks and in Stevenson Entrance, fulmars sometimes
concentrate in very large numbers, either by themselves or in company
with sooty shearwaters _(Puffinus griseus)_. In August 1973, FWS
observers crossing Perenosa Bay saw large numbers of tube-nosed birds
moving northeastward across the Bay. Although these appeared to be
predominantly shearwaters, there were also many fulmars. There was a
general movement of birds through Shuyak Strait from Shelikof Strait
into the Gulf of Alaska. It was not determined whether the fulmars were
moving with the shearwaters or on a regular feeding flight. Fulmars are
often found close to Afognak Island in the area between Sea Lion Rocks
and Sea Otter Island. Gabrielson and Lincoln (1959) reported seeing
swarms of fulmars in Marmot Strait and around the small islands on the
north side of Afognak in early August. Murie (1959) noted fulmars in
Shelikof Strait and again around the Shumagin Islands. There is nothing
in this record to indicate any change in their distribution at sea
recently.
The Semidi Islands support the Gulf of Alaska's largest fulmar breeding
population, a Class V colony (U.S. Bureau of Sport Fisheries and
Wildlife 1973). Gabrielson and Lincoln (1959) considered it to be one
of the four largest colonies in Alaska.
Gabrielson (1940) was told by Captain Sellevold of the marine vessel
_Brown Bear_ that he thought the birds nested on Sea Otter Island in
Perenosa Bay. Gabrielson also learned that they probably nested on
Sea Lion Rock at the head of Marmot Strait. In August 1973 I observed
fulmars in close proximity to Sea Lion Rock. More recently, small
numbers of apparently breeding fulmars have been found in the Barren
Islands (L. W. Sowl, personal observation and Edgar Bailey, unpublished
FWS report, Anchorage, Alaska). Although no other colonies are known or
suspected, the evidence suggests the possible existence of some.
Peterson and Fisher (1955), on noting dark fulmars between St. Paul
and St. George when only the light morph was present on any of the
colonies in the Pribilofs, expressed no surprise. They offered the
opinion that a round trip of 960 km to one of the dark morph colonies
in the Aleutians just might be within the operating range of a fulmar
on a 4-day vacation from nest-tending duties. Using this as a general
yardstick, it appears that the rich foraging grounds over the Portlock
Banks might also be within the range of breeding fulmars from the
Semidis. The trip up Shelikof Strait and on to Portlock Bank by way of
Shuyak Strait is only slightly longer than the one from Chagulak to St.
Paul. The feeding grounds off Montague Island would require a 1,600-km
round trip from the colonies in the Semidi Islands. Birds from the
Barren Islands and any colonies around Shuyak Island could easily reach
the Montague Island grounds, but why would they cross the Portlock
Banks to do so?
Fulmar colonies may be found in the Chiswell Islands. It is also a
possibility that the existence of colonies on islands along the north
coast of Afognak Island will be verified and that others will be
found in the vicinity of Shuyak Island. Gabrielson and Lincoln (1959)
expressed the opinion that there is almost certainly a colony on Sutwik
Island. If there is one, however, I did not see it on one quick trip
around the island in 1973.
Gabrielson (1940) expressed surprise at the size of the Semidi Island
breeding colony. Gabrielson and Lincoln (1959) considered 1911 to be
the first time breeding fulmars were found in the Shumagins. They
apparently based this on two eggs collected there that year and
documented in a plate in Bent (1964). Other than Gabrielson's opinion,
there is nothing to indicate a major change in fulmar status during
this century. If there has been a change in status, it has probably
been in the direction of increasing populations.
Fork-tailed Storm-petrel _(Oceanodroma furcata)_
The fork-tailed storm-petrel probably breeds throughout the Gulf of
Alaska. It is abundant at sea during the summer in most offshore
waters. Murie (1959) described it as the dominant petrel in the Bering
Sea and the North Pacific.
In view of its wide distribution and apparent abundance very little is
known about the fork-tailed storm-petrel's breeding colonies. Friedmann
(1935) recorded specimens and eggs from Kodiak dating back to 1843.
Murie (1959) noted them as nesting on Sanak Island and stated that they
almost certainly nested in the Shumagins and on other islands along the
Alaska Peninsula. David Roseneau (Isleib and Kessel 1973) found this
storm-petrel "breeding by the 10,000's" on East Amatuli Island in the
Barren Islands in June 1965. This was subsequently verified in 1974 by
Edgar P. Bailey (unpublished report, FWS, Anchorage, Alaska).
On 2 July 1972, responding to a tip by James W. Brooks (personal
communication), M. E. Isleib and I anchored at Fish Island in the
Wooded Islands. We did not locate any storm-petrel burrows, but a
steady flow of storm-petrels passed over the boat throughout the
darkest part of the night. Surveys conducted at about that time
provided an estimate of 19,000 fork-tailed storm-petrels in Prince
William Sound, primarily in or close to Montague Strait, and in
coastal waters on the east side of the Sound's outer islands. In this
area Isleib (personal communication) has noted a general movement
of fork-tailed storm-petrels westward around Montague Island and
into Prince William Sound through Montague Strait each morning and a
corresponding countermovement each evening. I conclude that in 1972
there was a Class IV colony in the Wooded Islands, numbering between
19,000 and 38,000 birds. Additional colonies will be discovered in a
similar manner as more systematic searches are made.
No colonies were discovered during the 1973 reconnaissance survey of
the islands south of Alaska Peninsula. Working primarily inshore, FWS
investigators encountered very few storm-petrels during the day. On
the night of 14 June, the FWS vessel, _Aleutian Tern_, responded to
a Mayday call and was either in transit or participating in rescue
operations from 2245 to 0420 h on the morning of 15 June. During
this period numerous fork-tailed storm-petrels were encountered,
particularly off Cape Wedge on Nagai Island. After we anchored in Eagle
Harbor on Nagai, more storm-petrels were heard about the vessel.
At about this same date, National Marine Fisheries Service enforcement
officers flying fisheries patrols observed storm-petrels in abundance
south of the Shumagin Islands (James Branson, personal communication).
These observations support the belief that there are probably
substantial undiscovered colonies in the Shumagin Islands.
Fork-tailed storm-petrels are abundant summer residents in the northern
Gulf of Alaska and the estimate by Isleib and Kessel (1973) is that
populations using the waters off the North Gulf Coast probably number
in the millions. Certainly the same estimate is valid for the rest of
the Gulf area west of the Chugach Islands.
The status of these birds relative to their historical abundance
cannot be derived from the existing information. There is strong
suspicion that the introduction of fox on many of the islands in the
area during the early part of this century probably caused a reduction
in their numbers. Murie (1959) said that experience taught him that
wings left from fox kills or remains of storm-petrels in fox droppings
could be accepted as evidence of the presence of a colony. Gabrielson
and Lincoln (1959) reported that E. P. Walker visited the Wooded
Islands in 1922 searching for a storm-petrel colony that had been
reported to exist there in 1918. He could not find it even though he
searched diligently. This apparent disappearance was attributed to the
introduction of fox.
There is another factor to consider, however. The limited number of
specimens now available from the Gulf of Alaska indicates that separate
subspecies occupy the eastern and western Gulf of Alaska. The accepted
boundary is somewhere in the vicinity of Prince William Sound. This
is an indication that there has been a hiatus in this area of rather
long duration. I have speculated that this sort of break may be in
some way related to the length of day and a period during the summer
when there is little darkness to cover activities near the colony.
Thoresen (1964) and Cody (1973) have both reported that western gulls
_(Larus occidentalis)_ assemble in Cassin's auklet colonies on moonlit
nights to prey on arriving adults. It is likely that other nocturnal
species would provoke the same sort of hunting tactic. A light-related
predation factor implies that the predators rely on sight. Avian
predators are indicated.
Leach's Storm-petrel _(Oceanodroma leucorhoa)_
Even less well understood than the breeding distribution of the
fork-tailed storm-petrel is that of Leach's storm-petrel.
Bendire (1895) quotes notes from Chase Littlejohn, who found
Leach's storm-petrel to be an abundant breeder on unspecified small
islands near Sanak in 1894. It greatly outnumbered the fork-tailed
storm-petrel. On his visit in 1937 Murie (1959) learned that all of the
large colonies of seabirds that had once existed there were gone. He
attributed this to overfishing and associated perturbation and to the
introduction of fox. No systematic assessment of seabirds on Sanak has
been attempted since Littlejohn's time.
No Leach's storm-petrel colonies have been encountered during
reconnaissance surveys of the Gulf of Alaska. Small numbers have been
reported from time to time and while it is very much less abundant
than the fork-tailed storm-petrel, I expect that it will be found
in small numbers at various places in the Gulf of Alaska when it
becomes possible to make more thorough searches. It may occur in
remote areas like the smaller islands scattered throughout the Sandman
Reefs--possibly even in large numbers. On the basis of the Sanak
record, we must assume that this storm-petrel has been greatly reduced
in numbers, at least in the western portion of the Gulf.
Double-crested Cormorant _(Phalacrocorax auritus)_
The white-crested cormorant, the race of the double-crested cormorant
residing in the Gulf of Alaska, is principally an inhabitant of the
marine environment. This cormorant is a common, but apparently patchily
distributed, resident throughout the northern and western Gulf of
Alaska.
Gabrielson and Lincoln (1959) thought that it nested only from Kodiak
Island westward into the Aleutians. However, it probably breeds from
Yakutat Bay westward. Isleib and Kessel (1973) estimated the abundance
of the double-crested cormorant along the North Gulf Coast as several
thousands, about one-tenth as common as the pelagic cormorant. It is
the third most abundant of the four cormorant species nesting in the
area. It occurs as scattered inclusions in many colonies throughout
the area, and at least in the Shumagin Islands, even occurs in some
colonies by itself.
There are no data on which to base an estimate of any change in status.
It probably is not much affected by many of the naturally occurring
perturbations.
Brandt's Cormorant _(Phalacrocorax penicillatus)_
On 22 July 1972, 13 Brandt's cormorants (4 sitting on nests) were
found at Seal Rocks in Hinchinbrook Entrance, Prince William Sound
(Isleib and Kessel 1973). Two years later I positively identified two
individuals in breeding plumage among a mixed group of cormorants in
the Chiswell Islands west of Seward. Are these recent range extensions?
Possibly, but I propose an alternative explanation.
Palmer (1962) showed the distribution of this cormorant as breeding
north to Puget Sound and as a straggler north to Forrester Island,
Alaska. This viewpoint is shared by the American Ornithologists' Union
(1957), which regards the bird as casual as far north as Forrester
Island, where this species was collected by Willet (1918).
Let us look at the other record, the one that is not supported by
specimens. Bent (1964) thought of Brandt's cormorant as a breeding
resident of Forrester Island. Gabrielson and Lincoln (1959) admonished
bird observers to be on the lookout for this particular cormorant
in the vicinity of Ketchikan and Prince of Wales Island. Brandt's
cormorant also appears on the bird list for the Kodiak National
Wildlife Refuge as an accidental visitor.
Early observers like Bent were explorers. They carefully examined and
made notes on all the birds they saw because there was always a chance
of a new discovery. It is also very probable that Bent paid particular
attention to the cormorants when he was at a place like Forrester
Island. He would have undoubtedly been very interested in trying
to confirm the presence of the now extinct Palla's cormorant _(P.
perspiculatus)_, as he must have been aware of Schlegel's (1862-64)
list of the birds in the Dresden Museum since Willet (1914) had
recently referred to it. The staffs for the Kodiak and Aleutian Islands
National Wildlife refuges have included some very careful observers,
such as Frank Beals. These men would have noticed the difference if a
new bird such as Brandt's cormorant was seen, verified the sighting
visually, and then noted it in their field diaries. They would not
have bothered to develop the type of proof needed for an undisputable
record, but the bird would have appeared in the refuge bird list (as it
does).
The outside coasts of the Alexander Archipelago, Kenai Peninsula,
and the Islands of the Kodiak Archipelago impose some logistical
requirements which discourage all but the most determined birders. Not
many have been able to reach more than very limited segments of the
entire coast. Given the vast distances involved, few of the FWS vessels
passing through the area have had the time to thoroughly examine any
cormorant colonies or roosts bird by bird. Even for those who pause,
the ever present swells and the constant chop of the summer westerlies
make positive identification difficult.
It is possible that Brandt's cormorant has been in the area in small
numbers for a long time, either regularly or intermittently. It could
have escaped observation because of the conditions described above.
This species may be there as a relict, as a pioneer, or only because
surplus birds are being pushed into marginal habitat by population
pressures on their main range to the south.
Pelagic Cormorant _(Phalacrocorax pelagicus)_
The pelagic cormorant is the most abundant of the four cormorants
residing in the Gulf of Alaska. It is found throughout coastal Alaska
south of the Bering Strait and even in some colonies in the southern
Chukchi Sea.
Cormorants have a certain invisibility which is brought about by their
universal presence. This blindness appears to have affected everyone,
even the earliest observers.
The earliest accounts provide a composite picture of the distribution
and abundance of the pelagic cormorant which is very similar to that
encountered today. In southeastern Alaska, beginning at the eastern
edge of the area under discussion, the pelagic cormorant was pictured
as the sole resident cormorant. However, we know from Willet's
collection of a Brandt's cormorant at Forrester Island that this might
not be quite true. From Yakutat Bay westward into the Aleutians this
species coexisted with the double-crested cormorant. In the Western
Aleutians there is some disagreement, but in general it appears to have
been accepted that the red-faced cormorant occurred there along with
pelagic and possibly double-crested cormorants. In the Bering Sea this
species coexisted with the red-faced cormorant.
A number of recent authors (Gabrielson 1940, 1944; Murie 1959; and
others) have considered the pelagic cormorant to be the most widely
distributed and abundant of the four species found in Alaska. Since the
modern picture fits, in a general way at least, it would be easy to
conclude that the species enjoys an unchanged status. There is just a
faint suggestion that this may not be true.
Dement'ev and Gladkov (1966) refer to a great die-off of pelagic
cormorants referred to earlier, in the Commander Islands. Stejneger
(1885) enlarges on this disaster. It is true that Stejneger visited
these islands a relatively short time after the die-off, but he
reported that even though the pelagic cormorants were increasing,
"people having seen their former multitude think that there is no
comparison between the past and the present." Murie (1959) thought
that the pelagic cormorant, while numerous, was outnumbered by the
red-faced cormorant in the Aleutians. More recently there has been the
rapid eastward expansion of the red-faced cormorant. Although it is not
possible to determine what the real status of the pelagic cormorant is
relative to its past status, I conclude that during this century its
status relative to that of the red-faced cormorant has declined.
Red-faced Cormorant _(Phalacrocorax urile)_
The red-faced cormorant, in spite of superficial similarities to the
pelagic cormorant, just does not look the same to an experienced
observer. However, it would have been possible for inexperienced
observers in the days before modern optics to overlook the differences.
The problem was further compounded by the "invisibility" of the
ubiquitous cormorants referred to earlier. Apparent absences or blank
spots in their range may not have been real.
Dement'ev and Gladkov (1966), reporting on the Russian record, stated
that the red-faced cormorant was common in the Commander Islands during
the last part of the 19th century and into the early part of the 20th.
Older authors had also reported it from Kamchatka and the Kurile
Islands. Now, according to Dement'ev and Gladkov, it is an uncommon
breeder on Mednyi Island in the Commander Islands and occurs only as an
autumn visitor to some of the southern Kurile Islands.
Turner (1885) reported that the double-crested cormorant was abundant
in the Near Islands and that the pelagic cormorant was common, but
makes no reference to the red-faced cormorant. One specimen of the
latter in the Leningrad Academy of Science was taken at Attu on 16
September 1844 (Gabrielson and Lincoln 1959), which indicates that
they were probably present during the period reported on by Turner
and, therefore, relatively uncommon. Clark (1911) identified red-faced
cormorants only a few times and in the Aleutians only once, near
Agattu. Dall (1874) noted two red-faced cormorants collected at
Amchitka but he (Dall 1873) apparently did not see any east of Unalaska.
Nelson (1887) apparently found red-faced cormorants breeding on the
Siberian and Alaskan mainlands at either side of Bering Strait, but
Bailey (1948) searched for some sign of their presence and found
none. Nelson (1887) also reported the red-faced cormorant from St.
Matthew and St. Lawrence islands in the northern Bering Sea and from
St. Michael and Nelson Island on the Alaskan coast. Gabrielson and
Lincoln (1959) pointed out that it has not been found breeding north
of the Pribilofs since then. Friedmann (1934) provides support for
Nelson by reporting red-faced cormorant bones from archeological sites
on St. Lawrence. Gabrielson and Lincoln (1959) cited two red-faced
cormorants in the Leningrad Academy of Science which were collected in
the Pribilofs in 1843. Dall and Bannister (1869) reported them to be
plentiful on St. George Island. Baird (1869) also noted their presence
in the Pribilofs.
Bent (1964) makes no mention of seeing the red-faced cormorant in the
Aleutians. He gives their breeding range as the Bering Sea region, the
Pribilof Islands, and perhaps the western Aleutians, the Commander
Islands, and the coast of Siberia north of North Cape. The American
Ornithologists' Union (1931) gave their breeding range as the Pribilof
Islands, the Commander Islands, and Siberia north to North Cape.
Murie (1959) found a colony of between 4,000 and 5,000 red-faced
cormorants nesting on Amak Island in 1925. In 1936 he was surprised
to find that the red-faced cormorant was the most abundant breeding
cormorant in the Aleutian Islands. Pelagic cormorants still appeared
to be most numerous, but there were large numbers of nonbreeding birds.
In 1936 he located "a good sized colony" of red-faced cormorants at
Unga in the Shumagin Islands. He found about 300 birds starting their
nests on 16 May.
In August 1946 Gabrielson (Gabrielson and Lincoln 1959) visited the
colony at Delarof Harbor, Unga, where several thousand cormorants
were observed. From a number of small samples he estimated that the
red-faced cormorants outnumbered pelagic cormorants five to two.
In 1973 I observed about 2,000 cormorants, mostly red-faced, in
this colony. Gabrielson also located them at two other sites in the
Shumagins and at Aghiyuk Island in the Semidi Islands.
Howell (1948) noted only double-crested cormorants at Double Island,
Kodiak. Shortly after that the leaflet, _Birds of the Kodiak Island
National Wildlife Refuge_ (first issued in 1955), listed red-faced
cormorants as common summer residents. The red-faced cormorant was next
found at Katchemak Bay about 1963. Isleib (Isleib and Kessel 1973)
first noticed red-faced cormorants wintering in Prince William Sound
in 1969. In July 1972 Isleib and Sowl had found a colony containing
75 nests at Point Elrington at the western approach to Prince William
Sound. By 1974 Isleib and Haddock (unpublished data, FWS, Anchorage,
Alaska) found them east of the Copper River Delta at Wingham Island.
The relatively rapid expansion of the range and apparent population
size of the red-faced cormorant is remarkable. But has this been a
real expansion into vast stretches of new territory? The record in the
literature which I have summarized shows, I think, something else.
We can demonstrate a historical range for the red-faced cormorant
that extends on the Asiatic Coast from North Cape, Siberia, south to
the Kurile Islands, the entire Aleutian Arc including the Commander
Islands, all the Bering Sea islands north to Bering Strait, Norton
Sound, Nelson Island, and the islands south of the Alaska Peninsula at
least as far east as Kodiak Island. The recently occupied coast from
Cook Inlet to the Copper River may represent a real range extension.
The breeding range of this species at the present time does not include
parts of its historical range west of the Commander Islands or north of
the Pribilof Islands.
The fragmentary record appears to show a long-term perturbation in the
range and populations of the red-faced cormorant that covers at least
100 years. I believe that we are probably seeing a recovery of lost
range and a return to something resembling a former distribution and
abundance.
What caused the perturbation? I am not prepared to answer this
question, but there are two occurrences which I find suggestive.
It is interesting to note (Dement'ev and Gladkov 1966) that on the
Commander Islands the red-faced cormorant was most abundant during the
first 50-odd years after the pelagic cormorants had been wiped out
in the winter of 1876-77. Perhaps some clues are to be found in the
interactions between these similar species.
It does not appear that the introduction of fox could have been a
causative factor. The first observations of population expansion were
noted almost concurrently with the heyday of the fox-farming industry.
Because of its choice of nesting habitat (very steep cliffs), this
cormorant would not have been affected by predators except for the one
that went into a very rapid population decline at a time that would
fit--the Aleut.
Jochelson (1968) and Hrdlicka (1945) summarized references to Aleut
clothing in the diaries and reports of early Russian visitors to
the Aleutian Islands. Evidently Aleut women sometimes wore a long,
robe-like parka made of harbor seal _(Phoca vitulina)_ skins or, for
women of high rank, parkas made of sea otter _(Enhydra lutra)_. The men
in almost all reports were said to have worn bird-skin parkas; puffins
and guillemots appear to have been preferred, but cormorants were
sometimes used. It took about 40 puffin skins to fabricate a parka and
a man evidently needed from one to three of these garments each year.
Sea otter populations were drastically reduced by Russian hunters. Rats
were introduced to the Aleutians very early during the Russian period
and must have had a substantial impact on populations of tufted puffins
and guillemots. The introduction of fox would have had a further impact
on burrow-nesting birds. Turner (1885) noted that Aleuts in the Near
Islands kept the fox confined to Attu so that they could keep the fox
away from the birds on Agattu. This is evidence of an Aleut recognition
of serious competition. Could cormorants, particularly red-faced
cormorants, have been preferred sources of fiber? Were Aleuts forced to
rely more heavily on cormorant skins as puffin and guillemot numbers
were reduced by rats and fox and sea otters by men?
Whatever the cause and effect, the status of red-faced cormorants now
appears to be better in the Gulf of Alaska than for at least the last
100 years.
Glaucous-winged Gull _(Larus glaucescens)_
The glaucous-winged gull is apparently one of the more successful
seabirds breeding in the Gulf of Alaska. While it is outnumbered (both
locally and in total abundance) by the black-legged kittiwake, it is
generally the most commonly seen and most uniformly distributed gull
in the Gulf of Alaska. Murie (1959) called it the common breeding gull
about the Alaska Peninsula. Cahalane (1943, 1944) considered it to be
numerous to abundant around Kodiak and in the Shelikoff Strait area.
Gabrielson (1944) reported that it could be seen in small numbers
everywhere. Most recently, Isleib and Kessel (1973) reported it to be
an abundant resident in the north Gulf Coast area. My own experience
would confirm these observations.
This gull appears to use a wider variety of nesting sites than some
others (Gabrielson and Lincoln 1959). Except where man's activities
have created new food sources, there appears to be a close link
between the location of glaucous-winged gull colonies and those of
murres, kittiwakes, and cormorants. Swartz (1966) found that during
the breeding season glaucous-winged gulls at Cape Thompson derived
almost all of their food from murre eggs and chicks. I have noted
small numbers of these gulls nesting, usually on turf near the tops of
cliffs, in most colonies of favored prey species.
The glaucous-winged gull is the principal scavenger throughout much
of coastal south-central Alaska. This has sometimes resulted in the
development of large concentrations near canneries and, more recently,
near dumps.
Two glaucous-winged gull concentrations stand out in the northern
Gulf of Alaska. One of these is on Egg Island at the western end of
the Copper River Delta. Patten (1976) estimated that this colony
contained 10,000-12,000 gulls in 1975. At times it appears to spread
onto nearby Hinchinbrook Island. M. E. Isleib (personal communication)
has estimated its size as high as 25,000 gulls. The other large
concentration is on the Susitna Flats across Cook Inlet from Anchorage.
This colony, or colony cluster, may be larger than the one at Egg
Island. There are no other known colonies even approaching these in
size. Most colonies range between a few pairs and 2,000-3,000.
Glaucous-winged gulls do not appear to have had any great changes
in population that can be detected from the literature. There have
almost certainly been local fluctuations in the number of breeding
birds as food supplies, such as canneries and dumps, have appeared
or disappeared in an area. Long-term changes in salmon runs have
undoubtedly had an impact as well. One other change, the reduced
level of egging, has undoubtedly had an effect also. Along the Alaska
Peninsula and in the Shumagin Islands, cannery workers of Filipino
heritage and fishermen who have a strong Aleut heritage still harvest
gull eggs for food. However, this activity is much reduced from what it
must have been.
Herring Gull _(Larus argentatus)_
The herring gull is a resident of Upper Cook Inlet and is found up and
down the coast from Prince William Sound to the Alaska Peninsula. Not
too much was learned about it during the recent FWS reconnaissance.
Williamson and Peyton (1963) reported the interbreeding of herring
gulls and glaucous-winged gulls in this area. This interbreeding has
resulted in a situation in which assignment of these gulls to one group
or another in the field can be rather arbitrary. The result has most
often been that field observers tend to lump them with glaucous-winged
gulls unless their herring gull characteristics are obvious. Specimens
collected by Williamson and Peyton (1963) indicate that herring gulls
have the edge in numbers in Upper Cook Inlet.
Black-legged Kittiwake _(Rissa tridactyla)_
The black-legged kittiwake is the most abundant gull in the northern
and western Gulf of Alaska. Colonies of this species can be found
throughout the entire area, and range in size from a few pairs
(Class I) to more than 100,000 birds (Class V). They may be found in
essentially pure colonies, but are often found sharing colonies with
murres.
The center of abundance for breeding black-legged kittiwakes in the
Gulf of Alaska is in the Semidi Islands, where Palmer Sekora (U.S.
Bureau of Sport Fisheries and Wildlife 1973) estimated that there were
426,000 breeding kittiwakes in 1972. He located kittiwake colonies at
eight sites, ranging in size from 1,000 to 109,000 nesting birds. The
size of the average colonial site was 27,000 birds. Ten sites were
Class IV in size and one was a solid Class V.
The easternmost known colony in the northern Gulf of Alaska is at
Wingham Island. Up to 1973, 22 colonies had been located in Prince
William Sound. The largest of these contained only 5,636 nests in 1972
(Isleib and Kessel 1973). Class IV or larger colonies are found at
Cape Resurrection, the Barren Islands, Chisik Island, Boulder Bay and
Cape Chiniak on Kodiak Island, and at Delarof Harbor and the Haystacks
in the Shumagin Islands. It is interesting to note that Gabrielson
(1940) considered Whale Island to be one of the largest known kittiwake
colonies in Alaska. He stated that there were many thousands of pairs
extending over a mile or more of cliff. He saw a second site which he
did not visit but looked equally large. A photograph in an article
by East (1943) also indicated the presence of a large colony. C. J.
Lensink (personal communication) estimated that there were about
100,000 kittiwakes in the colony in 1956. When last visited by Vernon
Berns (personal communication), this colony contained only 3,000 birds.
It is also of interest that Gabrielson (1940, 1944) did not notice
either the kittiwakes or the murres now breeding on Nord Island in the
Barren Islands or the kittiwakes on East Amatuli Island.
Whale Island and possibly the colonies in the Barren Islands give
evidence of local population fluctuations, but for the most part I have
not found an indication of a major perturbation over the past 40 years.
Before 1936, the record is too fragmentary to allow an assessment.
One of the interesting aspects of kittiwake ecology in the Gulf of
Alaska is the common occurrence of breeding failure. David Snarski
(December 1943 Quarterly Progress Report, Alaska Cooperative Wildlife
Research Unit, University of Alaska) observed breeding failure on
colonies in the Tuxedni National Wildlife Refuge in 1970 and 1971 and
obtained circumstantial evidence of another failure in 1972. In 1973
all of the breeding cliffs were occupied and nesting was successful.
Whatever the cause of these periodic failures, they do not yet appear
to have had a permanent impact that we are able to measure.
Red-legged Kittiwake _(Rissa brevirostris)_
Red-legged kittiwakes are not now known to breed in the western Gulf
of Alaska. Turner (1886) stated that he saw a few at Sanak in 1878. We
also have Stejneger's (1885) statement, that "red-legged" kittiwakes
nest from Bering Island to Sanak. Friedmann (1937) reported two
humeri from Kodiak Island middens. During the summer of 1976, two
birds were observed off Kodiak Island by Irving M. Warner (personal
communication), and one at 158°W and 54°30'-54°20'N south and east of
the Shumagin Islands (Patrick J. Gould, personal communication).
Turner (1885) listed the red-legged kittiwake as abundant and breeding
in the Near Islands. Turner (1886) also stated that he had seen quite a
number about a cliff back of the village on Akutan Island in 1878. He
added that to the westward this kittiwake was more abundant than the
black-legged kittiwake. Murie (1959) expressed the opinion that Turner
had confused the short-billed gull with the "short-billed" kittiwake.
Clark (1911) also reported that he had seen the red-legged kittiwake
in small numbers near Unalaska and that they became progressively
more common west to the Near Islands. Nelson (1887) reported seeing
large numbers of red-legged kittiwakes at Unalaska. Murie (1959) and
Gabrielson (1940, 1944) did not see any red-legged kittiwakes in the
Aleutian Islands. The species has recently been discovered breeding at
Buldir and Bogoslof islands (G. Vernon Byrd, personal communication).
Is it possible that we have here another species which is exhibiting a
response to some unknown long-term perturbation? The suggestion that
such an event has occurred is faint, but it is there. Do we have in
the red-legged and black-legged kittiwakes an example of yet another
congener pair that has been affected by some perturbation in which one
was affected positively and the other negatively? Clark (1911) reported
small numbers of black-legged kittiwakes to go with large numbers of
red-legged kittiwakes in the Near Islands, which is the reverse of the
current situation.
Arctic Tern _(Sterna paradisaea)_
Gabrielson and Lincoln (1959) attribute to the Arctic tern the most
extensive range of any Alaskan water bird. It is found in suitable
habitat everywhere north of Tracy Arm in Southeastern Alaska. Murie
(1959) stated that he found it nesting at suitable sites everywhere he
went. Isleib and Kessel (1973) considered it to be an abundant breeder
in Prince William Sound and along the northern Gulf Coast.
The Arctic tern was observed in FWS aerial surveys in Prince William
Sound, and surveys in July and August 1972 provided an estimate of
45,000 terns in the Sound (Isleib and Kessel 1973). On the other hand,
tern colonies were located only rarely in the FWS colony surveys before
1975. This is, however, a reflection of the equipment and methods used
and not of the abundance of terns.
From the fragmentary data available, it is not possible to detect
changes in Arctic tern status at the present time. We have to assume
that the widespread introduction of fox had at least local impact.
Although this tern uses a wide variety of nesting sites, it tends to
nest on flat sites where access by mammalian predators is easy.
Aleutian Tern _(Sterna aleutica)_
No Aleutian tern colonies were discovered in the Gulf of Alaska
area during FWS colony surveys in the early 1970's. This is again a
reflection of the fact that surveys were not designed to locate tern
colonies. Aleutian terns were encountered at least twice, once during
late March 1972 in Hawkins Cutoff, Prince William Sound, and again when
two birds were noted offshore from the Katmai National Monument on 30
May 1973 (L. W. Sowl, personal observations).
The type specimen of the Aleutian tern and a single egg were collected
at Kodiak Island on 12 June 1868 by Bischoff (Coues 1874). Fisher
(Gabrielson and Lincoln 1959) collected four more eggs in 1882. The
bird was not found breeding there until Howell (1948) found a colony
of 50 pairs at Bell's Flats in 1944. Walker (1923) found them nesting
on the Situk River, Yakutat, in 1917 and shortly thereafter saw them
at the Alsek River Flats. He also reported that D. H. Stevenson of
the Bureau of Biological Survey had told him that they nested on the
Isanotski Islands at the end of the Alaska Peninsula. This latter
report was the only one from the Aleutian Island chain for many years.
Isleib and Kessel (1973) considered it an uncommon local breeder in
the northern Gulf of Alaska. Isleib estimated its population at a
few hundred pairs on the Copper River Delta in May 1973 and 300-500
birds in June 1970. He also reported that they appeared more or less
regularly near Controller Bay and off the Situk River.
In recent years Aleutian terns have been seen with increasing frequency
in many places in western Alaska and the Aleutian Islands. This is
probably partly due to the increasing level of field work. At Amchitka
Island the several colonies that have been found in recent years are
almost certainly exhibiting a response to the removal of fox from the
island.
Although there is no way of determining what the past status of the
Aleutian tern has been in the Gulf of Alaska area, it has been there in
small numbers since it was first discovered on Kodiak. It has probably
not been abundant at any time and may have suffered a long-term decline
brought about by the introduction of fox.
Common Murre _(Uria aalge)_
The common murre is resident in the northern and western Gulf of
Alaska from Pinnacle Rock, Kayak Island, westward. East of Cook Inlet
colonies are located at Wingham Island, the Martin Islands, Middleton
Island, Porpoise Rock in Hinchinbrook Entrance, Barwell Island/Cape
Resurrection, the Chiswell Islands, the Barren Islands, and Chisik
Island.
For some reason, the islands of the Kodiak-Afognak Archipelago do not
host any known major murre colonies. There is also a rather large gap
between the Chisik Island colony and the next major colony at Oil
Creek west of Puale Bay. Directly west of Oil Creek is another colony
at Cape Unalishagvak. Both of these latter colonies are Class V and
they are the first colonies of this size to be encountered in the Gulf
of Alaska. West of these colonies the next large colony is at Atkulik
Island. To the south, midway between the last-named colonies, lies the
major composite murre colony in the Semidi Islands. These sites make
up the only Class VI colony in the Gulf of Alaska. Westward, the next
major colony, a Class V, is at Spitz Island south of Mitrofania Island.
In the Shumagin Islands one Class V colony is at Karpa Island, and
lesser colonies with large murre components are found at the Haystacks,
Castle Rock, and Bird Island. Only minor murre colonies are found
between the Shumagin Islands and the end of the Alaska Peninsula.
Gabrielson and Lincoln (1959) were aware only of the colonies at Cape
Resurrection (which Gabrielson considered to be large), at the Chiswell
Islands, and at Chisik Island for the area from Cook Inlet east.
Gabrielson visited the Barren Islands on 13 June 1940 and apparently
did not notice the present murre colonies, both Class IV, at East
Amutuli (an island which he visited) and Nord Island.
Gabrielson (Gabrielson and Lincoln 1959) found a few small colonies
at Kodiak, mostly on small offshore islands. Gabrielson found common
murres to be abundant in the Semidi Islands and stated that there were
no notable colonies in the Shumagins, although on his return to the
Shumagins in 1949 he did find a fairly large colony at the Haystacks.
That size description would fit the colony that is there now. He
obviously did not see the other colonies. Rausch (1958) reported murres
from Middleton Island.
There is quite a difference between the distribution of murres as we
know it today and the way Gabrielson and Lincoln pictured it. Why does
this difference exist? There are two possible answers: either the
number of colonies has increased, or the coverage of colony locations
has improved. The latter case, at least, is established. I must confess
to being puzzled by the way Gabrielson was able to move about close to
what are now known to be sizeable colonies without seeing them, those
in the Barren Islands and the Shumagin Islands in particular. Perhaps
this represents the vague outlines of yet another population change.
The center of abundance for murre distribution in the Gulf of Alaska
today is from Paule Bay west to eastern Shumagin Islands. The Semidi
Islands are the heartland of this area of maximum abundance. We have no
definitive data on species composition of these colonies. Common murres
undoubtedly dominate in most of the colonies; the only ones where we
know of a sizeable thick-billed murre component are in the Shumagin
Islands.
Thick-billed Murre _(Uria lomvia)_
Thick-billed murre population information cannot be separated from that
of the common murre on the basis of existing data. A direct assessment
of present-day status is not possible. After reviewing what we know
about their distribution, I suggest a way to examine the question
indirectly.
The thick-billed murre is found in colonies with the common murre from
Middleton Island westward; Rausch (1958) noted about 400 murres at
Middleton Island and observed that the thick-billed murre outnumbered
the common murre by several times. Isleib and Sowl (FWS, unpublished
data) saw a thick-billed murre mixed with common murres at Porpoise
Rock in July 1972. Isleib and Kessel (1973) expressed the opinion that
small numbers of thick-billed murres will be found in most common murre
colonies in the northern Gulf of Alaska when it is possible to survey
these colonies in detail. Karpa Island had a significant component
of thick-billed murres in June 1973, and they constituted 40% of the
colony at the Haystacks (L. W. Sowl, unpublished data).
Bent (1963) reported that many thick-billed murre eggs have been
taken by collectors at Round Island in the Shumagin Islands. Dall and
Bannister (1869) reported a thick-billed murre that was taken at
Kodiak in 1867.
The Gulf of Alaska is at the periphery of the breeding range of the
thick-billed murre. While it probably occurs in mixed colonies with the
common murre throughout this area, the thick-billed murre is much less
abundant. Occasionally in the Gulf of Alaska, a colony will be occupied
predominantly by the thick-billed murre. Gabrielson and Lincoln (1959)
noted that the thick-billed murre outnumbered the common murre in many
colonies in the Aleutians and that it became progressively more common
at higher latitudes.
We have almost no data relative to the species composition of murre
colonies in the Gulf of Alaska. Until we do it will not be possible to
fully understand the population status of the thick-billed murre. It
appears that changes in the species composition of murre colonies in
the Bering Sea may be an indicator of perturbation. The data for the
Gulf of Alaska are still too fragmentary to provide any indication of
whether or not the same indicator would work there. Close monitoring of
the Shumagin Islands colonies over a number of years might produce the
answer.
Earlier in this paper I noted the dramatic changes in species
composition of murre colonies on Walrus Island. Gabrielson and Lincoln
(1959) also commented on this well-documented and anything but static
situation. Investigators who visited this island during 1976 reported
seeing no murres on the island and only small numbers on offshore
rocks. James Bartonek (personal communication) said that this situation
has prevailed for several years.
There is an indication that a similar population fluctuation and
change in species composition of murre colonies have also occurred on
St. Matthew Island. Bent (1963) found mostly common murres and few
thick-billed murres at St. Matthew. Hanna (1916) saw only thick-billed
murres. Later, Gabrielson (1941) found this to be true in 1940.
Dramatic fluctuation in murre populations may be common and, at least
in some cases, the two species may be affected differently. Perhaps
this phenomenon has potential for providing us with an indicator of
some natural perturbations.
Peterson and Fisher (1955) expressed the opinion that thick-billed
murres arrived at the nesting ledges later than the common murre and
had to take the sites that were left. Tuck (1960) reported data from
the western Atlantic showing that thick-billed murres arrive later than
common murres. On the other hand, Belopol'skii (1961) reported data
showing that the two species arrive on breeding colonies in East Murman
simultaneously. At Cape Thompson, Swartz (1966) found that thick-billed
murres arrived about a week before common murres. The date of arrival,
while perhaps a contributing factor, is probably not decisive.
Interspecific competition of another sort is indicated.
In mixed murre colonies where there are large numbers of common murres,
this species occupies the choice nesting sites. Thick-billed murres are
usually left with the narrower ledges while the common murres occupy
the longer, broader ledges (Belopol'skii 1961). The broader ledges have
lower chick and egg mortality (Spring 1971). Spring also noted that
thick-billed murres are excluded from the centers of mixed colonies.
Johnson (1938) found that this contributes to higher losses of eggs to
predators and to the loss of other social benefits of occupying the
colony center (Johnson 1941).
Kozlova (1961) said that during the occupation of a colony there is
a sharp competitive struggle between the two species. In the end
thick-billed murres are pushed out to the periphery of the colonies
or left with narrow ledges or other equally unfavorable sites. Spring
(1971) studied the functional anatomy of both species and concluded
that the common murre is more successful in these encounters because it
has a more upright gait and greater agility than the thick-billed murre.
It follows that in a portion of their respective ranges, where the
two species overlap and where there is an equal chance that either
common murres or thick-billed murres will dominate a given colony,
the common murre dominates. I conclude from this that where there are
dramatic changes in species composition of murre colonies, such as at
Walrus Island, it is probably because the common murre has been greatly
reduced in numbers at the colony.
Spring (1971) concluded that the common murre is well adapted to
pursuit and capture of pelagic fishes and that the thick-billed murre
is better adapted for deep diving and the capture of benthic fishes
and pelagic and benthic invertebrates. Having greater latitude for
food selection, the thick-billed murre would have a greater tolerance
for ecological perturbations affecting the available food supply. The
common murre has an advantage when pelagic fishes are available but
cannot switch to the other foods as readily as can the thick-billed
murre. The low density of pelagic fishes in high arctic areas probably
also accounts for the greater success of the thick-billed murre at
higher latitudes relative to common murres.
Belopol'skii (1961) presented data from East Murman which indicates
that the common murre restricts its diet almost entirely to a small
number of fish species. Swartz (1966) found strong indications that
there were significant differences in the food preferences of the
two species of murres. Thick-billed murres made much greater use of
invertebrates. Bédard (1976) asserted that it is well known that the
common murre is quite partial to zooplankton. So again the issue is not
clear-cut.
The situation is, of course, much more complex than I have portrayed
it. Nonetheless, I think that it offers potential for use as a tool in
assessing population change and perturbations in the food supply which
should be studied quite closely.
Pigeon Guillemot _(Cepphus columba)_
Gabrielson and Lincoln (1959) noted that the pigeon guillemot was one
of the most regularly observed birds in Alaskan waters. It is found
everywhere throughout the northern and western Gulf of Alaska area,
with only a few understandable and relatively small blanks, such as in
the silty waters of Upper Cook Inlet. Because it obviously lacks the
breeding murres' need for close contact with its nearest neighbors, it
is able to exploit the available nesting habitat to the fullest. It
seems that literally every bit of suitable nesting habitat is normally
occupied.
Because of the dispersed way in which it breeds and because it does
much of its feeding in the onshore zone (which is hazardous for boats)
the pigeon guillemot is an almost impossible species to inventory by
standard methods.
There is no evidence that the pigeon guillemot has been greatly
affected by any major perturbation. Because of its choice of nesting
habitat, it is probably subject to the attack of only one egg predator,
the rat. Because of its loose social structure and the way it selects
nesting sites, eggs and young do not sustain loss from panic flights.
Its dispersed distribution should insure that man-made impacts such as
oil spills will have limited impact.
The population levels of the pigeon guillemot are probably relatively
very stable. The widespread introduction of the rat to most of its
nesting range undoubtedly had impact, but this impact has gone
undocumented. It would be interesting to follow the response of
guillemot populations on islands where rats had been totally removed,
if that ever becomes more than a dream.
Marbeled Murrelet _(Brachyramphus marmoratus)_
The marbled murrelet apparently breeds throughout most of the northern
and western Gulf of Alaska. This apparently is a necessary condition
because to date, at least in this part of Alaska, we can only guess
where and under what conditions this murrelet breeds.
In some relatively sheltered waters like Prince William Sound, where
marbled murrelets were estimated to number about 250,000 in 1972
(Isleib and Kessel 1973), they are the most abundant seabirds. We know
from Dixon (1908) and Grinnell (1910) that this has been so in Prince
William Sound since the beginning of the century. We know also that
the type specimens came from there as well (Stresemann 1949), which is
not necessarily an indication of abundance but is suggestive of their
abundance relative to species not collected.
Gabrielson (Gabrielson and Lincoln 1959) found marbled murrelets common
near Yakutat, in Prince William Sound, in Resurrection Bay, and at
Kodiak, and reported seeing them at the Chiswell Islands and at Chignik
and Pavlof Bay on the Alaska Peninsula. Cahalane (1943, 1944) found
them to be common in Kupreanof Strait, and along the Alaska Peninsula
north of Katmai Bay. Murie (1959) found them all along the Alaska
Peninsula. My own field notes from 1973 indicate that the only place
where they were common along the Alaska Peninsula was at Wide Bay.
We can sample marbled murrelet numbers by using standard transect
methodology; however, I have some very serious reservations about our
ability to convert these data into a population estimate. This is not
an unusual assessment for Alaskan seabirds in general, but I think it
is particularly apropos to this species.
We are still able only to guess at where the marbled murrelet nests and
we have not a clue as to what sort of nesting strategy they pursue. I
am not prepared to accept, on the basis of one North American record
(Binford et al. 1975), that tree nesting is its habit throughout its
range. What has been proved is that the marbled murrelet nests in trees
and not, as these authors would have us believe, that it does not nest
on the ground. It has become rather fashionable to ignore the Chichagof
Island record (a ground nest), but it has not been discredited. The
color of the Chichagof egg differs from that of the Big Basin egg, but
does agree with the one taken from an oviduct by Cantwell (Gabrielson
and Lincoln 1959). My own experience leads me to believe that tree
nesting, if it occurs, is not the common habit of marbled murrelets
nesting in the Prince William Sound region.
After many hours of observing marbled murrelets over a period of
several years, I am intrigued by a number of things. These birds, as
often as not, appear to be clustered in "pairs" as they feed. This
occurs even at what should be the height of the breeding season. On
several occasions I have noted a very pronounced evening flight of
these birds from gathering areas on the water up into the surrounding
mountains at sunset. This has moved me to wonder if their nesting
strategy includes incubating at night but less than full-time
attendance on days when the eggs can be warmed by the sun. We know that
periodic egg-neglect is an aspect of storm-petrel behavior (Pefaur
1974). Is this behavior also possible on a more regular basis in an
alcid? If so, it would certainly help explain why nests are hard to
find.
It is apparent that more needs to be known about the population
dynamics and life history of the marbled murrelet before we can make a
proper estimate of its abundance. In spite of the fragmentary record,
I conclude that the marbled murrelet probably enjoys the same relative
abundance and distribution that it did at the beginning of the century.
Kittlitz's Murrelet _(Brachyramphus brevirostris)_
The Kittlitz's murrelet is not as abundant as the marbled murrelet,
but locally it is sometimes found in large numbers. FWS surveys
conducted during July-August 1972 provide an estimate of 57,000
murrelets of this species in Prince William Sound. Almost a fifth of
these were concentrated in Unakwik Inlet above Unakwik Reef. Even more
interesting, about 2,500 of these birds were concentrated in one loose
flock.
In addition to Unakwik Inlet, Kittlitz's murrelets concentrate in
College Fjord in Prince William Sound and in the waters fronting the
Bering-Malaspina ice-fields (Isleib and Kessel 1973). Common as they
are in these waters, this species is supposed to be even more abundant
at Glacier Bay. The common feature of these waters is the amount of ice
that can be found below their tributary glaciers.
The Kittlitz's murrelet is apparently distributed from LeConte Bay,
east of Petersburg, Alaska, north to Point Barrow and west across the
Aleutians to Attu, where Murie collected a pair (Gabrielson and Lincoln
1959). I once flushed a murrelet from an area of tread and riser
topography near the top of the highest point on Kiska Island in heavy
cloud cover, and although I could not see this bird well, I thought it
to be of this species. From the range description in Gabrielson and
Lincoln (1959) and Udvardy's (1963) range map, it is apparent that
the distribution of this species is rather patchy, but I suspect that
for the more mountainous part of its range this is more apparent than
accurate. The record is too fragmentary to allow an assessment of any
change in status during the historical period.
Ancient Murrelet _(Synthliboramphus antiquus)_
Chase Littlejohn (Bendire 1895) spent the spring and summer of 1894
collecting eggs on islands south of the Alaska Peninsula. He has left
us a detailed record of what he saw but not where he saw it. Bent
(1963) stated flatly that the site of his collecting was Sanak Island
and this has common acceptance. Several things in his account point
to a site which was a small island with several peers close by, but
this could not have been Sanak. It could have been an island in the
Sanak Island group or it could equally well have been somewhere in the
Sandman Reefs. Unfortunately, because of this the record is clouded.
There has never been anything approaching a survey of the southern half
of the Sandman Reefs. We do not know what breeding colonies are there.
At any rate, Littlejohn told of the large numbers of Leach's
storm-petrels, fork-tailed storm-petrels, auklets (of which only
Cassin's is specifically identified), and ancient murrelets which
occupied a large number of small islands. He could not calculate the
number of breeding murrelets on his small island, the size of which I
interpret to have been of the same order of magnitude as two others
which he estimated were about 2 acres. He does say that the murrelets
must have numbered several thousand and could, if left alone by the
Aleuts, have quickly grown too numerous for the island to accommodate.
Murie (1959) made a brief visit to Sanak in 1937 and learned that
there were no longer any large colonies of seabirds. He attributes
this to exploitation of the fisheries and to the fox-farming industry.
Littlejohn told of the repeated visits of Aleuts to his small islands,
where they took hundreds of birds each time and all of the eggs they
could find. This kind of activity could not help but disrupt the
breeding on these islands.
Littlejohn's description of the ancient murrelet's nest leaves little
doubt that the birds could be reached by fox or rats with ease. The
birds showed no particular care in selecting a nest site and often
worked their way back no more than about a meter into the dead
vegetative cover from preceding years, where they scratched out a
shallow nest.
There are few records of the ancient murrelet from the northern and
western Gulf of Alaska. Friedmann (1935) reported the collection of
a series of eggs in 1884 on Kodiak Island. Chase Littlejohn (Bendire
1895) collected eggs from somewhere in the Sanak Group in 1894. In 1908
Dixon (Grinnell 1910) saw a bird in Port Nellie Juan. Several were seen
by Jaques (1930) near Belkofski in May 1928. Gabrielson collected one
bird at Cordova in September 1941 and another at the Chiswell Islands
in July 1945 (Gabrielson and Lincoln 1959). He saw numerous flocks in
the Gulf of Alaska on 30 July of an unnamed year. In 1943, he would
have been near Cape Spencer on that date. In 1945 he would have been
near the Chiswell Islands. In either case, he was probably somewhere in
Blying Sound.
The ancient murrelet is relatively uncommon but regularly observed
in the inshore waters along the outer coasts of the islands fronting
Prince William Sound. FWS surveys in July-August 1972 provided an
estimate of almost 1,000 birds, mostly in nonbreeding plumage, along
the outer coast of Prince William Sound (Isleib and Kessel 1973). Small
numbers were found feeding close to the Wooded Islands on 24 July (my
personal observation). Rausch (1958) saw a few off Middleton Island in
1956. Isleib (Isleib and Kessel 1973) saw 400-500 widely distributed
at the mouth of Yakutat Bay in July and August 1968. The only large
numbers of ancient murrelets encountered on the FWS survey of the
Alaskan Peninsula in 1973 were in the Shumagin Islands. They were very
common in East Nagai Strait on 9 June and more than half of the 1,300
seabirds per square nautical mile encountered between Little Koniuji
and Chernabura Islands on 11 June were ancient murrelets. At Nagai
Island an estimated 5,000 ancient murrelets were observed in the west
bay at Pirate Shake, and later (on 19 June) several were observed in
the vicinity of Midun Island (FWS, Anchorage, Alaska, unpublished data).
On the basis of the observations recounted above, I have to conclude
that ancient murrelets are fairly regularly, if patchily, distributed
throughout the northern and western Gulf of Alaska. I do not believe
that the void in their range shown for the northern Gulf of Alaska
by Udvardy (1963) is correct. Several colonies are there, awaiting
discovery.
Ancient murrelets are not abundant in the Gulf of Alaska but they are
certainly more numerous than we have been able to prove. It is not
possible to tell from the existing data whether they were once more
abundant than they are now. I suspect, on the basis of the Sanak Island
experience, that we can conclude that this species has been reduced in
number by various of man's activities.
Cassin's Auklet _(Ptychoramphus aleuticus)_
Cassin's auklet is a very uncommon bird in the northern Gulf of Alaska.
In the western Gulf it is more common, particularly from the Shumagins
west.
This auklet apparently once bred in great numbers on islands in or near
the Sanak Group where Chase Littlejohn (Bendire 1895) found them to be
twice as numerous as the ancient murrelets. Murie (1959) did not find
them there.
Littlejohn began encountering Cassin's auklets at sea some 290 km
southeast of Unga, Shumagin Islands. Murie (1959) encountered them near
the Shumagins in May 1937. During the FWS 1973 reconnaissance survey of
the Alaska Peninsula, these auklets were not encountered (or at least
not identified) until we reached the vicinity of Unga Strait where we
saw a few in mixed flocks with other murrelets and auklets. They were
most numerous in East Nagai Strait. We encountered them only twice in a
situation which indicated they might be breeding--on Hall and Herendeen
islands on the north end of Little Koniuji Island.
Murie (1959) considered Cassin's auklet to be no longer common west of
Kodiak. In Gabrielson's many voyages through the northern and western
Gulf of Alaska he encountered them only twice, once off Cape Spencer
and once in the Chiswell Islands.
Thoresen (1964) commented that throughout the northern part of its
range the Cassin's auklet has become gradually less frequent. Although
there are no data to dispute this, I believe, as do Isleib and Kessel
(1973), that they are more numerous than observations would indicate,
and I would apply this to the entire area. There are certainly colonies
remaining in the Shumagin Islands, and quite probably along the south
coast of the Kenai Peninsula. When it is possible to fully explore the
Sandman Reefs there is a good probability that they will be found there.
We can only guess at the reasons for their decline. Bendire (1895) and
Murie (1959) have described some contributing factors.
Parakeet Auklet _(Cyclorrhyncus psittacula)_
Gabrielson and Lincoln (1959) described the parakeet auklet as the
least colonial of any of the Alaskan auklets. They also considered the
Aleutian Islands to be its principal nesting grounds. There are old
records of breeding parakeet auklets from Kodiak (Friedmann 1935) and
Little Koniuji (Bean 1882). Grinnell (1910) reported two that were seen
on Green Island, Prince William Sound, and several more that were seen
near Knight Island.
Murie (1959) did not see any parakeet auklets near Kodiak and Afognak
islands which he considered to be the eastern part of their range. He
did not think they were abundant anywhere along the Alaska Peninsula.
He found a few near Sutwik Island in May 1936 and then noted that they
were fairly common near the Shumagins in May 1937.
Gabrielson found this species to be quite numerous on the north side of
Chowiet Island in the Semidi Islands in 1945 (Gabrielson and Lincoln
1959). He also saw numerous individuals in Marmot Strait and saw one in
the Chiswell Islands during the same year. David Roseneau (Isleib and
Kessel 1973) found hundreds close to East Amatuli Island in the Barren
Islands in 1965.
During FWS colony surveys, parakeet auklets have been found in close
proximity to six seabird colonies in Prince William Sound. During the
July-August 1972 surveys, they were estimated to number about 3,000 in
the Sound. They have also been found closely associated with Chisik
Island (David Snarski, personal communication), the Chiswell Islands,
Nord and Sud islands in the Barrens, Sea Otter Island, and Central
and Long islands along the Alaska Peninsula. They were most numerous
in the Shumagin Islands, where they were found near Castle Rock, Hall
(9,000), Herendeen (3,000), Atkins (more than 5,000), and Little
Koniuju islands. They were again encountered south and west of Cold Bay
at High, Fawn, Let, Amagat, Umga, and Patton islands. Many of these
islands are in the north half of the Sandman Reefs, the only portion
where any attempt has been made to survey seabird colonies.
The parakeet auklet may not be abundant anywhere in the Gulf of Alaska
but, based on the numbers of places it has been seen in recent years,
its population appears to be well dispersed and probably doing very
well. This auklet is most abundant from the Shumagin Islands westward.
It is almost certainly more numerous than has been thought. Its habits
are secretive enough so that it could easily escape notice.
Because the parakeet auklet nests predominantly under boulders, it
probably was not much affected by fox. Rats would certainly have
reduced its numbers wherever these were introduced into its breeding
habitat. We have no data to tell us whether there may have been
population fluctuations in the past, but there undoubtedly were at
least minor ones locally after rats were introduced.
Crested Auklet _(Aethia pygmaea)_
Udvardy (1963) shows the breeding range of the crested auklet as
extending from southern Kodiak Island westward. Within the northern and
western Gulf of Alaska, it is certainly most abundant in the eastern
Shumagin Islands.
Isleib saw this auklet in Prince William Sound 3 times during the
winter of 1972-73. These are the only records he was aware of for that
area (Isleib and Kessel 1973). David Roseneau (Isleib and Kessel 1973)
saw several in Amatuli Cove, Barren Islands, in June 1965. I observed
one in the vicinity of Cape Spencer in August 1973.
Friedmann (1935) listed the crested auklet as a breeding bird at
Kodiak, but considered it to be much more abundant as a wintering bird.
Townsend (1913) has provided us with a vivid description of the myriads
of crested auklets he encountered at Yukon Harbor, Little Koniuji
Island. Gabrielson and Lincoln (1959) noted large numbers of crested
auklet around Simeonof and Bird islands in the Shumagin Islands in 1946
and stated that the Yukon Harbor colony was still thriving.
Crested auklets were not encountered on the 1973 FWS reconnaissance
survey until we reached the Shumagin Islands. They were abundant
only at the southeastern end of Little Koniuji, where we encountered
perhaps 10,000 in Yukon Harbor and more than 50,000 in a small cove
directly south of Yukon Harbor on the opposite side of the island. As
numerous as they were, they did not match Townsend's myriads or even
come close to his assessment that they "were here more numerous than
the 'choochkies' at St. George." St. George Island in the Pribilofs is
famous for its least auklets which, in the past, have been estimated to
number as high as 36 million (Peterson and Fisher 1955). The numbers
there today do not even approach this level and we have no way of
knowing how abundant they were when Townsend visited the Pribilofs,
but I think it is safe to say that they probably numbered in the
millions. There are probably more crested auklets than we observed on
Little Koniuji, but there is certainly no longer anything approaching
millions of birds. Properly pronounced, Koniuji is the Aleut name for
the crested auklet, so we can assume that the original inhabitants were
impressed by its numbers.
During the 1973 FWS survey we did not see crested auklets at either
Simeonof or Bird islands. On the overgrazed and cattle-trampled
Simeonof it does not seem possible that any could still exist.
I suspect that a cattleman's greed has been the undoing of any crested
auklets that may have nested on Simeonof Island. This would not account
for the loss of any colonies that may have been on Bird Island, but
the decaying fox-trapper's cabin on that island undoubtedly tells
the story. Churnabura, with its feral cattle, presents much the same
problem as Simeonof. As for Little Koniuji, have horned puffins been
partly responsible for the decrease in crested auklets? The puffin
colony at the south end of Little Koniuji must be exactly where
Townsend's millions of crested auklets once nested.
Least Auklet _(Aethia pusilla)_
No least auklets were encountered in FWS surveys in the Gulf of Alaska
in the early 1970's. Udvardy (1963) shows their breeding range as
starting well west in the Aleutians. Gabrielson and Lincoln (1959) give
the eastern limit of their breeding range as the Shumagin Islands. Bent
(1963) listed their breeding range as extending east to Kodiak Island,
and Friedmann (1935) knew of only a few specimens taken in the winter
from Kodiak. Perhaps least auklets nested somewhere in the western Gulf
of Alaska, and they may still, but at the moment we have no evidence to
prove that they do.
Rhinoceros Auklet _(Cerorhinca monocerata)_
Udvardy (1963) would have us believe that the rhinoceros auklet did not
nest between southeastern Alaska and the southern Kurile Islands. Bent
(1963_b_), on the other hand, lists their breeding range as extending
from Washington to Agattu. Clark (1910) noted this species in small
numbers at Atka and Agattu. Because of the lack of proof, Udvardy
probably had no options. I believe that Bent was probably closer to
describing their original range. I base this assumption on recent
observations and on the additional fragments of information reported by
Gabrielson and Lincoln (1959). Murie (1959) failed to find this species
anywhere in the Aleutians, but his primary reason for being there, the
fox-farming industry, may have had a lot to do with his not being able
to find any.
The FWS surveys in Prince William Sound in July-August 1972 located
small numbers of rhinoceros auklets in breeding plumage at the Wooded
Islands and at Stoney Island and Channel Island in Montague Strait.
These birds gave every impression of being local breeders. David
Roseneau (Isleib and Kessel 1973) encountered two at the Barren Islands
in June 1965. Isleib and Kessel (1973) list a few other records from
this area.
My own experience leads me to believe that there is a large colony
somewhere on Afognak Island, probably on or near Tonki Cape. On 30 May
1973 I noted a lone bird north of Afognak Island. Later, on 8 and 9
August, I saw several in the same area. On 13 August in Marmot Strait I
observed a number of rhinoceros auklets, either singly or in groups of
up to 12. Some of these had small fish in their beaks. As they flushed,
they all flew off toward Tonki Cape. This observation was made just at
last light, and I believe that there were many others about that could
not be seen in the dying light. We did not encounter this species along
the Alaska Peninsula during the FWS survey in 1973 until we reached
the end. There I had one quick glimpse of what I was certain was a
rhinoceros auklet at Amagat Island.
Horned Puffin _(Fratercula corniculata)_
The horned puffin is one of the most abundant breeding birds in the
Gulf of Alaska. There are only a few really large colonies but these
birds breed just about anywhere there is a cliff (even a low one) with
suitable fractures and crevices. During the Alaska Peninsula surveys
in 1973, I estimated that the frequency with which these birds were
seen on the water was about half that of the tufted puffin. They have
been recorded in so many places that there is nothing to be gained by a
reiteration of the record in the literature.
The horned puffins reach their greatest density in the Gulf of Alaska
west of Kodiak Island. Murie (1959) estimated that the colony at Amagat
Island, Morzhovi Bay, contained 15,000 birds, one of the largest he had
seen. It contained at least 50,000 in 1973. Even at that, it was no
match for the colony on Little Koniuji Island with its minimum 140,000
horned puffins. Other colonies with large horned puffin components
were at High Island (40,000), Castle Rock (20,000), Mitrofani Island
(35,000), and Sosbee Bay (15,000).
Earlier in this paper, I commented at length on the great and often
rapid fluctuations in populations of tufted puffins. The same
phenomenon affects horned puffins. In 1975 there were relatively small
numbers of horned puffins at Little Koniuji where they had flourished
2 years earlier (James Bartonek, personal communication). Because they
are apparently subject to erratically oscillating populations, it is
hard to tell how they have fared over the years.
Tufted Puffin _(Lunda cirrhata)_
The tufted puffin, as previously indicated, is also a bird with
widely fluctuating populations. Until we develop an understanding of
their population dynamics and can understand the underlying cause of
these fluctuations it will not be possible to assess trends in their
populations or understand the implications of such trends.
Tufted puffins are abundant throughout the Gulf of Alaska. Small
colonies can be located almost anywhere. Along the Alaska Peninsula
there are a number of colonies with an estimated breeding population
in 1973 of more than 15,000 birds. These are: Ashiiak Island (20,000),
Central Island (90,000), the Brother Islands (45,000), The Haystacks
(19,000), Castle Rock (85,000), Bird Island (none, but may contain
500,000-1,000,000 at times), Peninsula Islands (35,000), the Twins
(18,000), Amagat Island (40,000), and Umga Island (22,000). These
colonies correspond to the area where colonies were listed for the
horned puffin.
Tufted puffin populations respond readily to some undetermined
short-term perturbations. This is clearly demonstrated by their rapid
population fluctuations. Because of their numbers and because of the
apparent rapidity with which their numbers rebound, it is not so
apparent that they have been affected by long-term perturbations, as so
many other seabirds apparently have.
There is much unused or underused nesting habitat suitable for this
species. In some cases there are very strong clues pointing to why this
habitat is vacant. On many islands along the Alaska Peninsula, which
have very good-looking tufted puffin nesting habitat and no puffins,
there are visible signs of the presence of fox--either fox trails or
abandoned trappers' cabins. I also suspect that the brown bear _(Ursa
arctos)_ is another possible contributing factor to population declines
of burrow nesters along this coast. I have seen brown bears swimming
from island to island on foraging expeditions. George J. Divoky
(personal communication) has found brown bears visiting Ugaiushak
Island, which is 13 km from shore. There are other islands between
Ugaiushak and the mainland but the shortest route from shore would
require one swim of 7 km. The motivation must be strong.
Tufted puffins may shift from colony to colony. This could be an
explanation for apparent local population fluctuation, but if so, I
am puzzled by the apparent tenacity with which puffins cling to some
sites. Their constant occupancy of sites where the vegetative mat is
breakaway tundra (Amundsen 1972) or is underlain by sand results in the
destruction of these sites. Tufted puffins often cling to them in spite
of the fact that they have been reduced to "slums."
My conclusion is that in spite of their large numbers it appears that
tufted puffin populations in the Gulf of Alaska probably have been
reduced to a level below that of their undisturbed state.
Conclusions
Seabird numbers in the Gulf of Alaska are not static. Generally, they
are probably much less abundant than they were when Bering made his
voyage of discovery. There are, nonetheless, considerable numbers of
seabirds breeding along the coasts of these waters. Some species show
signs of recovery from past insults by man. With enlightened management
there is still time to preserve the vast natural heritage that they
represent and, in many cases, to improve their status.
In attempting to address a complicated subject in short space and a
relatively narrow frame of reference, I have certainly erred a number
of times. I would like to see the wealth of new data that will be
derived from current work applied to this concept. An understanding
of past population fluctuations and the underlying perturbations that
they reflect is essential for managers faced with the problem of making
good decisions on measures to mitigate the potential adverse impact of
development.
References
American Ornithologists' Union. 1931. Check-list of North American
birds, 4th ed. American Ornithologists' Union, Baltimore, Md. 530
pp.
American Ornithologists' Union. 1957. Check-list of North American
birds, 5th ed. American Ornithologists' Union, Baltimore, Md. 691
pp.
Amundsen, C. C. 1972. Plant ecology of Amchitka Island. Amchitka
bio-environmental program. Final Report, Battelle Columbus Lab.,
Columbus, Ohio. 27 pp.
Bailey, A. M. 1948. Birds of arctic Alaska. Colo. Mus. Nat. Hist.
Pop. Publ. 8. 316 pp.
Baird, S. F. 1869. On additions to the bird fauna of North America,
made by the scientific corps of the Russo-American Telegraph
Expedition. Trans. Chic. Acad. Sci. 1(2):311-325.
Beaglehole, J. C. 1974. The life of Captain James Cook. Stanford
Univ. Press, Stanford, Calif. 734 pp.
Bean, T. H. 1882. Notes on birds collected during the summer of
1880 in Alaska and Siberia. Proc. U.S. Natl. Mus. 5:144-173.
Bédard, J. 1976. Coexistence, coevolution and convergent evolution
in seabirds: a comment. Ecology 57(1):177-184.
Belopol'skii, L. O. 1961. Ecology of sea colony birds of the
Barents Sea. (Transl. from Russian.) Israel Program for
Scientific Translations, Jerusalem. 346 pp.
Bendire, C. 1895. Notes on the ancient murrelet (Synthliboramphus
antiquus) by Chase Littlejohn with annotations. Auk 12(3):270-278.
Bent, A. C. 1963. Life histories of North American diving birds.
Dover Publications, Inc., New York. 239 pp.
Bent, A. C. 1964. Life histories of North American petrels,
pelicans and their allies. Dover Publications, Inc., New York.
335 pp.
Binford, L. C., B. G. Elliot, and S. W. Singer. 1975. Discovery of
the nest and downy young of the marbled murrelet. Wilson Bull.
87(3):303-319.
Bowles, J. H. 1908. Tapeworm epidemic among Washington seabirds.
Condor 11:33.
Cahalane, V. H. 1943. Notes on the Kodiak-Afognak Island group. Auk
60(4):536-541.
Cahalane, V. H. 1944. Birds of the Katmai region, Alaska. Auk
61(3):351-375.
Clark, A. H. 1910. The birds collected and observed during the
cruise of the United States Fisheries Steamer "Albatross" in the
North Pacific Ocean and in the Bering, Okhotsk, Japan and Eastern
seas from April to December 1906. Proc. U.S. Natl. Mus. 38:25-74.
Cody, M. L. 1973. Coexistence, coevolution and convergent evolution
in seabirds. Ecology 51(1):31-44.
Coues, E. 1874. Birds of the Northwest. U.S. Geological Survey of
the Territories, Misc. Publ. 3. 791 pp.
Dall, W. H. 1873. Notes on the avifauna of the Aleutian Islands,
from Unalaska eastward. Proc. Calif. Acad. Sci. 5(1):25-35.
Dall, W. H. 1874. Notes on the avifauna of the Aleutian Islands,
especially those west of Unalaska. Proc. Calif. Acad. Sci.
5:270-281.
Dall, W. H., and H. M. Bannister. 1869. List of the birds of
Alaska, with biographical notes. Trans. Chic. Acad. Sci.
1(2):267-310.
Dement'ev, G. P., and N. A. Gladkov, eds. 1966. Birds of the Soviet
Vol. I. (Transl. from Russian.) Israel Program for Scientific
Translations, Jerusalem. 553 pp.
Dixon, J. S. 1908. Field notes from Alaska. Condor 10:139-143.
East, B. 1943. Seabird cities of the Aleutians. Nat. Hist. 51:64-71.
Fisher, J., and R. M. Lockley. 1954. Seabirds. William Collins and
Sons, London. 320 pp.
Friedmann, H. 1934. Bird bones from Eskimo ruins on St. Lawrence
Island. J. Wash. Acad. Sci. 24:83-96.
Friedmann, H. 1935. The birds of Kodiak Island, Alaska. Bull. Chic.
Acad. Sci. 5(3):13-54.
Friedmann, H. 1937. Bird bones from archeological sites in Alaska.
J. Wash. Acad. Sci. 27:431-438.
Gabrielson, I. N. 1940. America's greatest bird concentrations,
Part I. Bird Lore 42:497-506.
Gabrielson, I. N. 1941. America's greatest bird concentrations,