_Icteridæ_, which includes such familiar species as the bobolinks,
orioles, meadow larks, and the various kinds of blackbirds, none of
which, I am glad to say, are parasites. The name _Molothrus_ has been
given to the genus that includes the cowbirds. They are confined to
the American continent, having no analogues in the lands across the
seas. The same may be said, indeed, of the whole _Icteridæ_ family. It
may be a matter of surprise to many persons that there are twelve
species and subspecies of cowbirds in North and South America, for
most of us are familiar only with the common cowbird (_Molothrus
ater_) of our temperate regions. Of these twelve species only three
are to be found within the limits of the United States, one is a
resident of western Mexico and certain parts of Central America, while
the rest find habitat exclusively in South America. A fresh field of
investigation is open to some enterprising and ambitious naturalist
who wishes to study several of these species, as comparatively little
is known of their habits, and indeed much still remains to be learned
of the whole genus, familiar as one or two of the species are. Their
sly, surreptitious manners render them exceedingly difficult to study
at close range and with anything like detail.
Are all of them parasites? It is probable they are--at least to a
greater or less degree--except one, the bay-winged cowbird of South
America, which I shall reserve for notice later on in this article. We
might assert that our common cowbird is the parasite _par excellence_
of the family, for, so far as I can learn from reading and
observation, they never build their own nests or rear their own young,
but shift all the duties of maternity, save the laying of the eggs,
upon the shoulders of other innocent birds.
These avian "spongers" have a wide geographical range, inhabiting the
greater part of the United States and southern Canada, except the
extensive forest regions and some portions of the Southern States. The
center of their abundance is the States bordering on the upper
Mississippi River and its numerous tributaries. They occur only as
stragglers on the Pacific coast west of the Cascade and Sierra Nevada
Mountains. The most northern point at which they have been known to
breed is the neighborhood of Little Slave Lake in southern Athabasca.
In the autumn the majority of these birds migrate to southern Mexico,
although a considerable number remain in our Southern States, and a
few occasionally tarry for the winter even as far north as New England
and southern Michigan.
The male cowbird looks like a well-dressed gentleman--and may have
even a slightly clerical air--in his closely fitting suit of glossy
black, with its greenish and purplish iridescence, and his cloak of
rich metallic brown covering his head, neck, and chest. He makes a
poor shift as a musician, but his failure is not due to lack of
effort, for during courtship days he does his level best to sing a
variety of tunes, expanding and distorting his throat, fluffing up his
feathers, spreading out his wings and tail, his purpose evidently
being to make himself as fascinating as possible in the eyes of his
lady love. One of his calls sounds like the word "spreele," piped in
so piercing a key that it seems almost to perforate your brain.
One observer maintains that the cowbirds are not only parasitical in
their habits, but are also absolutely devoid of conjugal affection,
practicing polyandry, and seldom even mating. This is a serious
charge, but it is doubtless true, for even during the season of
courtship and breeding these birds live in flocks of six to twelve,
the males almost always outnumbering the females. However, if their
sexual relations are somewhat irregular, no one can accuse them of
engaging in family brawls, as so many other birds do, for both males
and females seem to be on the most cordial terms with one another, and
are, to all appearances, entirely free from jealousy. Who has ever
seen two cowbirds fighting a duel like the orioles, meadow larks, and
robins? Their domestic relations seem to be readily adjusted, perhaps
all the more so on account of their lax standards of sexual virtue.
In obtruding her eggs into the nests of other birds Madame Cowbird is
sly and stealthy. She does not drive the rightful owners from their
nests, but simply watches her opportunity to drop her eggs into them
when they are unguarded. No doubt she has been on the alert while her
industrious neighbors have been constructing their domiciles, and
knows where every nest in the vicinity is hidden. Says Major Charles
Bendire: "In rare instances only will a fresh cowbird's egg be found
among incubated ones of the rightful owners. I have observed this only
on a single occasion." From one to seven eggs of the parasite are
found in the nests of the dupes. In most cases the number is two, but
in the case of ground builders the cowbird seems to have little fear
of overdoing her imposition. Major Bendire says that he once found the
nest of an ovenbird which contained seven cowbird's eggs and only one
of the little owner's.
If parasitism were the only crime of the cowbird one would not feel so
much disposed to put her into the avian Newgate Calendar; but she not
only inflicts her own eggs upon her innocent victims, but often
actually tosses their eggs out of the nests in order to make room for
her own. Nor is that all; she will sometimes puncture the eggs of the
owners to prevent their hatching, and thus increase the chances of her
own offspring. Whether this is done with her beak or her claws is
still an open question, Major Bendire inclining to the belief that it
is done with the claws.
Her finesse is still further to be seen in the fact that she usually
selects some bird for a victim that is smaller than herself, so that
when her young hopefuls begin to grow they will be able to crowd or
starve out the true heirs of the family. In this way it is thought
that many a brood comes to an untimely end, the foster parents having
no means of replacing their own little ones when they have been
ejected from the nest. However, I am disposed to think that the
cowbird's impositions are not usually so destructive as some observers
are inclined to believe. I once found a bush sparrow's nest containing
one cowbird and four little sparrows, all of which were in a thriving
condition. The sparrows were so well fed and active that as soon as I
touched the nest they sprang, with loud chirping, over the rim of
their cottage and scuttled away through the grass. They were certainly
strong and healthy, in spite of the presence of their big foster
brother. Before they flitted away I had time to notice how the little
family were disposed. The cowbird was squatted in the center of the
nest, while his little brothers and sisters were ranged around him,
partly covering him and no doubt keeping him snug and warm. They were
further advanced than he, for while they scrambled from the nest, he
could do nothing but snuggle close to the bottom of the cup, where he
was at my mercy.
A wood thrush's nest that I found contained two young thrushes and two
buntings. All of them were about half fledged. Being of nearly the
same size, the queerly assorted bantlings lived in apparent peace in
their narrow quarters. I watched them at frequent intervals, but saw
no attempts on the part of the foundlings to crowd out their
fellow-nestlings. The cowbirds were the first to leave the roof-tree.
Thus it appears that the intrusion of the cowbird's eggs does not
always mean disaster to the real offspring of the brooding family, but
of course it always prevents the laying of the full complement of eggs
by the builders themselves.
Even after the youngsters have left the nest the mother cowbird does
not assume the care of them, but still leaves them in charge of the
foster parents. It is laughable, almost pathetic, to see a tiny
ovenbird or redstart feeding a strapping young cowbird which is
several times as large as herself. She looks like a pygmy feeding a
giant. In order to thrust a tidbit into his mouth she must often stand
on her tiptoes. Why the diminutive caterer does not see through the
fraud I can not say. She really seems to be attached to the hulking
youngster. By and by, however, when he grows large enough to shift for
himself, he deserts his little parents and nurses and seeks
companionship among his own blood kindred, who will doubtless bring
him up in the way all cowbirds should walk.
It is surprising how many species are imposed on successfully by the
cowbird. The number, so far as has been observed, is ninety, with
probably more to be added. Among the birds most frequently victimized
are the phoebes, the song sparrows, the indigo birds, the bush
sparrows, and the yellow-breasted chats. Even the nests of the
red-headed woodpecker and the rock wrens are not exempt. Some species,
notably the summer warblers, detect the imposture and set about
defeating the purposes of the interloper. This they do by building
another story to their little cottage, leaving the obtruded eggs in
the cellar, where they do not receive enough warmth to develop the
embryo.
While it is surprising that acute birds should allow themselves to be
imposed on in this way, perhaps, after all, they look upon the cowbird
as a kind of blessing in disguise; at least, he may not be an unmixed
evil. They may act on the principle of reciprocity--that "one good
turn deserves another." What I mean is this: In my rambles I have
often found the cowbirds the first to give warning of the approach of
a supposed danger. Having no domestic duties of their own, they can
well secrete themselves in a tall tree overlooking the entire
premises, and thus play the useful rôle of sentinel. This, I am
disposed to believe, is one of the compensating uses of this parasite,
and may furnish the reason for his being tolerated in birdland. And he
_is_ tolerated. Has any one ever seen other birds driving the cowbird
away from their breeding precincts, or charging him with desperate
courage as they do the blue jays, the hawks, the owls, and other
predatory species? He evidently subserves some useful purpose in the
avian community, or he would not be treated with so much
consideration.
A young cowbird that I purloined from the nest and reared by hand did
not prove a very pleasant pet. He was placed in a large cage with
several other kinds of young birds. At first he was quite docile,
taking his food from my hand and even allowing some of his feathered
companions to feed him; but in a few weeks he grew so wild and
manifested such a fierce desire for the outdoor world that I was glad
to carry him out to the woods and give him his freedom. A young
red-winged blackbird and a pair of meadow larks developed a different
disposition.
The dwarf cowbird (_Molothrus ater obscurus_) is similar to his
relative just described, except that he is smaller and his
geographical range is more restricted. He is a resident of Mexico,
southern Texas, southwestern Arizona, and southern California. His
habits resemble those of the common cowbird. Another bunting, having
almost the same range, although a little more southerly, is the
red-eyed cowbird, which is larger and darker than our common cowbird
and has the same parasitical habits.
In South America three species have been studied by Mr. W. H. Hudson,
who, in collaboration with Mr. P. L. Sclater, has published a most
valuable work on Argentine ornithology. One of these is called the
Argentine cowbird (_Molothrus bonariensis_). It is a _bona fide_,
blue-blooded parasite, and has been seen striking its beak into the
eggs of other birds and flying away with them. The males, it is said,
show little discrimination in pecking the eggs, for they are just as
likely to puncture the cowbird eggs as those of other birds. Every egg
in a nest is frequently perforated in this way. These buntings lay a
large number of eggs, often dropping them on the ground, laying them
in abandoned nests, or depositing them in nests in which incubation
has already begun, in which cases all of them are lost. However, in
spite of this wastefulness the birds thrive, thousands of them being
seen in flocks during the season of migration.
And, by the way, a description of their habits by Mr. Hudson has
thrown an interesting light on the subject of migration in the
southern hemisphere. South of the equator the recurrence of the
seasons is the exact reverse of their recurrence north of the equator,
and therefore the breeding season of the birds is in the autumn
instead of the spring; the flight from winter cold occurs in the
spring instead of in the autumn, and is toward the north instead of
toward the south. Thus, in February and March the Argentine cowbirds
are seen flying in vast battalions in the direction of the equatorial
regions--that is, northward--in whose salubrious clime they spend the
winter. As our northern autumn draws near and the southern summer
approaches these winged migrants take the air line for their breeding
haunts in the Argentine Republic and Patagonia. At the same time the
migrants of the northern hemisphere are pressing southward before the
blustering mien of old Boreas. It all seems wonderful and solemn, this
world-wide processional of the seasons and the birds.
Naturally, one would expect to find some other eccentricities in this
aberrant family besides that of parasitism, and in this expectation
one is not disappointed. There are two other species of cowbirds in
the Argentine country--the screaming cowbird (_Molothrus
rufoaxillaris_) and the bay-winged cowbird (_Molothrus badius_). The
latter is only partly a trencher on the rights of other birds--that
is, it is only half a parasite. Indeed, it sometimes builds its own
nest, which is quite a respectable affair; but, as if to prove that it
still has some remnants of cowbird depravity in its nature, it
frequently drives other birds from their rightful possessions,
appropriates the quarters thus acquired, lays its eggs into them, and
proceeds to the performance of its domestic duties like its
respectable neighbors. Its virtue is that it never imposes the work of
incubation and brood rearing on any of its feathered associates, even
though it does sometimes eject them from their premises.
But what is to be said of the screaming cowbird? Instead of inflicting
its eggs on its more distant avian relatives it watches its chance and
slyly drops them into the domicile of its bay-winged cousins, and
actually makes them hatch and rear its offspring! This seems to be
carrying imposture to the extreme of refinement, or possibly
developing it into a fine art, and reminds one of those human
good-for-naughts who "sponge" off their relatives rather than go among
strangers. One can scarcely refrain from wondering whether grave
questions of pauperism and shiftlessness ever enter into the
discussion of "the social problem" in the bird community.
THE COLUMBUS MEETING OF THE AMERICAN ASSOCIATION.
BY PROF. D. S. MARTIN.
The Columbus meeting of the American Association for the Advancement
of Science was looked forward to with considerable interest as the
first in the new half century of that body. Would the impression and
stimulus of the great semicentennial gathering at Boston last year be
found to continue, or be followed by a reaction? The meetings west of
the Alleghanies are always smaller than the eastern ones, and the
brilliancy of the Boston meeting could not be looked for in any
interior city. The general expectation was for an "off-year"
gathering.
But only in point of attendance was this impression verified. The
register of those present showed three hundred and fifty-three
names--a good number for an interior meeting, very few of the Western
gatherings having exceeded it. In all other respects the general
feeling of the members indicates that the meeting was notably
successful and enjoyable, and the remarks made by the writer a year
ago as to the real value of the smaller and less conspicuous meetings
he feels to have been well exemplified. It was a scientific working
meeting, with enough of social intercourse and attentions to be
delightful, but not distracting. In these aspects the "golden mean"
was markedly preserved.
The arrangements of the local committee for the convenience of the
members and the success of the meeting in general were remarkable in
their completeness. Nothing seems to have been overlooked, and some
advances were made upon any previous year. The daily programmes were
well printed and on hand early every morning--a most important point,
not always heretofore attained. A complete telephone service between
the section rooms and the central hall was a feature of special
advantage, each section reporting to headquarters every paper as it
was taken up. This was then posted on a bulletin, so that any one
could know at any time what was going on in each section. A great
amount of delay and disappointment, that has often been felt by
members anxious to hear certain papers in different sections, was thus
entirely obviated. Columbus has set an example in this feature that
must be followed in the arrangements for all future meetings. The
entire service on these telephones was rendered not by professional
operators, but by young lady students of the university, and it was
well and gracefully done.
It is fitting also that recognition should be given to some who have
been less prominent in the local arrangements, but have had a large
share in their preparation. While the public resolutions of thanks
have made well-deserved mention of the local committee and its
officers, especially Prof. B. F. Thomas, the indefatigable secretary,
it is known in Columbus that much of the planning and arranging was
the work of Prof. Edward Orton, Jr., the son of the president of the
meeting, and that very much is owing to his laborious activity in the
perfection of the local adjustments.
The place of meeting was eminently pleasant and suitable--the wide
campus and fine buildings of the Ohio State University. To members
from the East it was a matter of great interest to see this noble
institution, one of the best examples of the great educational
enterprises of the central States. In his address of welcome at the
opening of the association the president of the university, Dr.
William O. Thompson, outlined the history of public education in the
West as dating back to provisions in the "Ordinance of 1787," looking
to educational advantages for the great "Northwest Territory." The
State University of Ohio is one of the youngest of its kind, but now
one of the most important, among the States formed from that great
region, although Ohio was the first to be organized into Statehood.
Among the numerous fine structures scattered over the broad area of
the campus, one of the most interesting is Orton Hall, containing the
collections in geology and archæology, which are very extensive, as
well as the laboratories, workrooms, and classrooms of the geological
department, and at present the University Library. Here the meetings
of Section E (Geology and Geography) were held. In the adjacent
Botanical Hall, with its greenhouses, etc., Section G held its
meetings. But most of the sections met in Townshend Hall, where the
telephone service above described connected all the rooms.
The Ohio State University not only welcomed and accommodated the
association, but had a strong representation among the officers of the
meeting. The venerable president, Dr. Orton, has long been professor
of geology in the university, and his collections are displayed in the
hall that so appropriately bears his name. Section C (Chemistry) and
Section G (Botany) both had secretaries from the university
faculty--Professors Weber and Kellerman, respectively--while the
arrangements for the meeting have been already spoken of as largely
due to Professor Thomas and Professor Orton, Jr.
The ladies' reception committee did everything for the comfort and
convenience of the visiting ladies. Their musicale and garden party in
the grounds were described as extremely enjoyable, and the provision
of private carriages to convey ladies and aged members across the
broad spaces of the campus to and from the entrances was a very
delicate and highly esteemed convenience, especially on warm days. The
association was favored in the weather, which, though somewhat hot out
of doors, was not severe, and the rooms were pleasant and airy.
The excursions given to the members were all of them scientific; they
were not merely pleasure trips. This point was a marked feature of the
Columbus meeting, and one well worthy of future imitation as far as
may be. Not every place, however, has such marked facilities in this
respect. On Saturday, August 26th, three free excursions were provided
to points of geological or archæological interest. They were about
equally shared by the members, together with representatives of the
local committee. One party left on Friday evening, passing the night
at Sandusky, and going by boat thence to the celebrated islands of
Lake Erie, there to see the wonderful glacial furrows in the
corniferous limestone on Kelley's Island and the recently opened
strontia cave on Put-in-Bay Island. These islands are also favorite
pleasure resorts for the whole neighborhood, and the trip was one of
great interest and enjoyment. Another party, on Saturday morning, went
to points of special importance in the coal region of the Hocking
Valley, under the direction of Mr. R. M. Haseltine, chief mine
inspector of Ohio. At Corning the party went down into Mine No. 8,
owned by the Sunday Creek Coal Company, which has recently been
equipped with electric power generated by utilizing the waste gas from
neighboring gas-wells. This is said to be the first mine in Ohio to
improve this natural source of power. At a depth of sixty-five feet
the visiting party were taken by mine cars to a point where a
remarkably fine exposure has been made of a carboniferous "forest,"
with upright trunks of _Sigillaria_ and associated forms of coal
vegetation finely displayed. At a point somewhat nearer the entrance,
but at a lower level, lunch was served by the company, in a chamber
lighted by electricity, two hundred feet underground and a mile from
daylight! Another mine was visited later, and the machinery and
appliances examined; this was No. 16, at Hollister, owned by the
Courtright Coal Company.
The third party went to Fort Ancient to examine the great aboriginal
earthworks at that place, owned by the State, and in charge of the
Ohio Archæological Society. Here, on a hill widely overlooking the
Little Miami Valley, are some of the most extensive prehistoric works
in the country. The State has purchased two hundred and eighty-seven
acres, and of these about one hundred acres are included within the
walls. These ramparts, overgrown with large trees, follow closely the
contour of the hills, and show that, whatever their age, there has
been no change and little erosion since they were built. Their form is
very irregular, consisting of two main areas--a northern one, called
the "new fort," rudely square, and a southern one, called the "old
fort," rudely triangular--connected by a narrow portion, called the
"isthmus," with crescent-shaped transverse walls crossing it, and high
conical mounds at the entrance to the "old fort." From the main
gateway of the "new fort," starting from two mounds, two parallel
walls can be traced, exactly eastward, for half a mile or more.
Irregular as these works are, from the contour of the hills and the
course of the ravines that bound them, yet there is also seen at times
in their shaping a singular exactness of orientation that is striking
and suggestive. Their use is problematical, but they must have been
defensive, although an enormous force would be required to hold them,
as their entire circumference is three miles and a half. At one point
within the "old fort," in front of the gateway to the "isthmus," was
found a burial place where a number of skeletons lay as though thrown
together, not carefully and separately buried. The suggestion is
strongly made that this spot marks an unsuccessful attack by enemies,
who were roughly buried where they fell. At other points graves have
been found, some containing copper implements and overlaid with plates
of mica. Great regret was felt that Mr. W. K. Moorehead, who has
explored so extensively here and in the vicinity and has published
such interesting accounts of Fort Ancient and similar remains, was
unable to be at the meeting on account of severe illness.