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UNIVERSITY OF KANSAS PUBLICATIONS
MUSEUM OF NATURAL HISTORY
Volume 12, No. 14, Pp. 575-655, 10 figs.
May 18, 1964
The Breeding Birds of Kansas
BY
RICHARD F. JOHNSTON
UNIVERSITY OF KANSAS
LAWRENCE
1964
UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY
Editors: E. Raymond Hall, Chairman, Henry S. Fitch,
Theodore H. Eaton, Jr.
Volume 12, No. 14, Pp. 575-655, 10 figs.
Published May 18, 1964
UNIVERSITY OF KANSAS
Lawrence, Kansas
PRINTED BY
HARRY (BUD) TIMBERLAKE, STATE PRINTER
TOPEKA, KANSAS
1964
[Union Label]
30-1476
The Breeding Birds of Kansas
BY
RICHARD F. JOHNSTON
CONTENTS
PAGE
INTRODUCTION 577
DISTRIBUTION OF BIRDS IN KANSAS 579
Avian habitats in Kansas 581
Species reaching distributional limits in Kansas 584
BREEDING SEASONS 588
Introduction 588
Variation in breeding seasons 589
Zoogeographic categories 593
Significance of phylogeny to breeding schedules 595
Regulation of breeding schedules 598
ACCOUNTS OF SPECIES 601
ACKNOWLEDGMENTS 652
LITERATURE CITED 652
INTRODUCTION
The breeding avifauna of Kansas has received intermittent attention from
zoologists for about 75 years. Summary statements, usually concerning
all birds of the state, have been published by Goss (1891), Long (1940),
Goodrich (1941), Tordoff (1956) and Johnston (1960). All but the first
dealt with the breeding birds chiefly in passing, and none was concerned
primarily with habitat distributions and temporal characteristics of
Kansan birds. The present work treats mainly certain temporal
relationships of breeding birds in Kansas, but also geographic
distribution, habitat preferences, and zoogeographic relationships to
the extent necessary for a useful discussion of temporal breeding
phenomena.
Information on breeding of some of the 176 species of birds known to
breed in Kansas is relatively good, on a few is almost non-existent, and
on most is variously incomplete. It is nevertheless possible to make
meaningful statements about many aspects of the breeding biology and
distribution of most species of Kansan birds; we can take stock, as it
were, of available information and assess the outstanding avenues of
profitable future work. In the accounts of species below, the
information given is for the species as it occurs in Kansas, unless it
is otherwise stated. For the various subsections analyzing biology and
distribution, only information taken in Kansas is used, and for this
reason the analyses are made on about half the species breeding in the
state. An enormous amount of observational effort has been expended by
several dozen people in order that suitable data about breeding birds of
Kansas be available; all persons who have contributed in any way are
listed in the section on acknowledgments, following the accounts of
species.
Kansas has been described topographically, climatically, and otherwise
ecologically many times in the recent past; the reader is referred to
the excellent account by Cockrum (1952), which treats these matters from
the viewpoint of a zoologist. For present purposes it will suffice to
mention the following characteristics of Kansas as a place lived in by
birds.
Topographically, Kansas is an inclined plane having an elevation of
about 4100 feet in the northwest and about 700 feet in the southeast.
West of approximately 97 deg. W longitude, the topography is gently rolling,
low hills or flat plain; to the east the Flint Hills extend in a nearly
north to south direction, and to the east of these heavily weathered,
grassy hills is a lower-lying but more heavily dissected country, hills
of which show no great differences in elevation from surrounding
flatland.
The vegetation of eastern Kansas comingles with that of the western edge
of the North American deciduous forest; a mosaic of true forest,
woodland remnants, and tall-grass prairie occupies this area east of the
Flint Hills. From these hills west the prairie grassland today has
riparian woodland along water-courses; the prairie is composed of
proportionally more and more short-grass elements to the west and
tall-grass elements to the east.
Climate has a dominating influence on the vegetational elements sketched
above. Mean annual rainfall is 20 inches or less in western sectors and
increases to about 40 inches in the extreme eastern border areas. Mean
monthly temperatures run from 25 deg.F. or 30 deg.F. in winter to 80 deg.F. or 90 deg.F.
in summer. The northwestern edges of Caribbean Gulf warm air masses
regularly reach northward only to the vicinity of Doniphan County, in
northeastern Kansas, and extend southwestward into west-central
Oklahoma; these wet frontal systems are usually dissipated along the
line indicated by masses of arctic air, sometimes in spectacular
fashion. The regular recurrence of warm gulf air is responsible for the
characteristically high relative humidity in summer over eastern Kansas
and it has an ameliorating effect on winter climate in this region.
Almost immediately to the north in Nebraska and to the west in the high
plains, summers are dryer and winters are notably more severe. The
breeding distributions of some species of birds fairly closely
approximate the distribution of these warm air masses; these examples
are noted where appropriate below.
DISTRIBUTION OF BIRDS IN KANSAS
Birds breeding in Kansas are taxonomically, ecologically, and
distributionally diverse. Such diversity is to be expected, in view of
the mid-continental position of the State. Characteristics of insularity,
owing to barriers to dispersal and movement, tend to be lacking in the
makeup of the avifauna here. The State is not, of course, uniformly
inhabited by all 176 species (Table 1) of breeding birds; most species
vary in numbers from one place to another, and some are restricted to a
fraction of the State. Variations in numbers and in absolute occurrence
are chiefly a reflection of restriction or absence of certain plant
formations, which is to say habitats; the analysis to follow is thus
organized mainly around an examination of gross habitat-types and the
birds found in them in Kansas.
TABLE 1.--THE BREEDING BIRDS OF KANSAS
Woodland Species
_Elanoides forficatus_ N[A] _P. bicolor_ O
_Ictinia misisippiensis_ U _Sitta carolinensis_ O
_Accipiter striatus_ U _Troglodytes aedon_ N
_A. cooperii_ U _Thryomanes bewickii_ N
_Buteo jamaicensis_ O _Thryothorus ludovicianus_ N
_B. lineatus_ N _Mimus polyglottos_ N
_B. platypterus_ N _Dumetella carolinensis_ N
_Aquila chrysaetos_ O _Toxostoma rufum_ N
_Falco sparverius_ U _Turdus migratorius_ O
_Colinus virginianus_ N _Hylocichla mustelina_ N
_Phasianus colchicus_ O _Sialia sialis_ O
_Meleagris gallopavo_ N _Bombycilla cedrorum_ N
_Philohela minor_ U _Lanius ludovicianus_ O
_Zenaidura macroura_ N _Sturnus vulgaris_ O
_Ectopistes migratorius_ N _Vireo atricapillus_ N
_Conuropsis carolinensis_ U _V. griseus_ N
_Coccyzus americanus_ N _V. bellii_ N
_C. erythropthalmus_ N _V. flavifrons_ N
_Otus asio_ U _V. olivaceus_ N
_Bubo virginianus_ O _V. gilvus_ N
_Strix varia_ U _Mniotilta varia_ N
_Asio otus_ U _Protonotaria citrea_ N
_Aegolius acadicus_ U _Parula americana_ N
_Caprimulgus carolinensis_ N _Dendroica aestiva_ N
_C. vociferus_ U _D. discolor_ N
_Phalaenoptilus nuttallii_ N _Seiurus motacilla_ N
_Chaetura pelagica_ U _Oporornis formosus_ N
_Archilochus colubris_ N _Icteria virens_ N
_Colaptes auratus_ N _Wilsonia citrina_ N
_C. cafer_ N _Setophaga ruticilla_ N
_Dryocopus pileatus_ O _Passer domesticus_ O
_Centurus carolinus_ N _Icterus spurius_ N
_Melanerpes erythrocephalus_ N _I. galbula_ N
_Dendrocopos villosus_ O _I. bullockii_ N
_D. pubescens_ O _Quiscalus quiscula_ N
_Tyrannus tyrannus_ S _Molothrus ater_ N
_T. vociferans_ S _Piranga olivacea_ N
_Muscivora forficata_ S _P. rubra_ N
_Myiarchus crinitus_ S _Richmondena cardinalis_ S
_Sayornis phoebe_ S _Pheucticus melanocephala_ S
_Empidonax virescens_ S _P. ludoviciana_ S
_Contopus virens_ S _Guiraca caerulea_ S
_Iridoprocne bicolor_ N _Passerina ciris_ S
_Progne subis_ N _P. cyanea_ S
_Cyanocitta cristata_ N _P. amoena_ S
_Pica pica_ O _Spinus pinus_ O
_Corvus brachyrhynchos_ O _S. tristis_ O
_C. cryptoleucus_ O _Loxia curvirostra_ O
_Parus atricapillus_ O _Pipilo erythrophthalmus_ N
_P. carolinensis_ O _Chondestes grammacus_ N
_Spizella passerina_ N
Limnic Species
_Podilymbus podiceps_ U _Butorides virescens_ U
_Phalacrocorax auritus_ U _Florida caerulea_ U
_Ardea herodias_ U _Casmerodius albus_ U
_Leucophoyx thula_ U _Porzana carolina_ U
_Nycticorax nycticorax_ U _Laterallus jamaicensis_ U
_Nyctanassa violacea_ U _Gallinula chloropus_ U
_Ixobrychus exilis_ U _Fulica americana_ U
_Botaurus lentiginosis_ U _Charadrius alexandrinus_ U
_Plegadis chihi_ U _Actitis macularia_ U
_Branta canadensis_ U _Steganopus tricolor_ U
_Anas platyrhynchos_ U _Sterna albifrons_ U
_A. acuta_ U _Chlidonias niger_ U
_A. discors_ U _Telmatodytes palustris_ N
_A. clypeata_ U _Cistothorus platensis_ N
_Aix sponsa_ U _Geothlypis trichas_ N
_Aythya americana_ U _Xanthocephalus xanthocephalus_ N
_Oxyura jamaicensis_ U _Agelaius phoeniceus_ N
_Rallus elegans_ U _Rallus limicola_ U
Grassland Species Xeric Scrub Species
_Buteo swainsonii_ N _Callipepla squamata_ N
_B. regalis_ U _Geococcyx californianus_ N
_Circus cyaneus_ O _Salpinctes obsoletus_ N
_Tympanuchus cupido_ N
_T. pallidicinctus_ N
_Pedioecetes phasianellus_ N Unanalyzed Species
_Charadrius vociferus_ U
_Eupoda montana_ U _Cathartes aura_ N
_Numenius americanus_ U _Coragyps atratus_ N
_Bartramia longicauda_ U _Falco peregrinus_ U
_Speotyto cunicularia_ U _Columba livia_ O
_Asio flammeus_ U _Tyto alba_ U
_Sayornis saya_ S _Chordeiles minor_ U
_Eremophila alpestris_ O _Megaceryle alcyon_ U
_Dolichonyx oryzivorus_ N _Riparia riparia_ O
_Sturnella magna_ N _Stelgidopteryx ruficollis_ N
_S. neglecta_ N _Hirundo rustica_ O
_Spiza americana_ N _Petrochelidon pyrrhonota_ U
_Calamospiza melanocorys_ N
_Ammodramus savannarum_ N
_Passerherbulus henslowii_ N
_Aimophila cassinii_ N
_Spizella pusilla_ N
[A] The letter following each name refers to presumed zoogeographic
derivation of the species, modified after Mayr (1946).
N = North American evolutionary stock;
S = South American stock;
O = Eurasian stock; U = unanalyzed.
Avian Habitats in Kansas
Four major habitat-types can be seen in looking at the distribution of
the breeding avifauna of Kansas. These are woodland, grassland, limnic,
and xeric scrub plant formations. A little more than half the breeding
birds of Kansas live in woodland habitats, about one-fifth in limnic
habitats, about one-eighth in grassland habitats, and less than two per
cent in scrub habitats; this leaves some 6.4 per cent of the breeding
avifauna unanalyzed (Table 2).
TABLE 2.--ANALYSIS OF THE BREEDING AVIFAUNA OF KANSAS BY
HABITAT-TYPES
========================+===============================
| Percentage of the Avifauna of
+--------+-----------+----------
HABITAT-TYPE | | North | Stated
| Kansas | America | Habitat
------------------------+--------+-----------+----------
Woodland: 101 species | 58 | 16.7 | 44.4
Limnic: 36 species[B] | 21 | 6.0 | 38.5
Grassland: 23 species | 13 | 3.8 | 71.3
Xeric scrub: 3 species | 2 | 0.5 | 10.2
Unanalyzed: 11 species | 6 | 2.0 | 55.0
+--------+-----------+----------
Totals: 174 species | 100 | 29.0 | 43.2
------------------------+--------+-----------+----------
[B] Does not include the Canvasback (_Aythya valisineria_),
the Forster Tern (_Sterna forsteri_), and the Black Tern
(_Chlidonias niger_), all recently added to the breeding
avifauna of Kansas.
_Woodland Habitats_
One hundred one species of Kansan birds are woodland species (tables 1
and 2). The analysis of Udvardy (1958) showed woodland birds to be the
largest single avifaunal element in North America, with 38 per cent of
North American birds relegated to it. It is likewise the largest element
in the Kansan avifauna, representing 58 per cent of Kansan birds.
Although woodland makes up a relatively small fraction of the
vegetational complexes in Kansas, a large number of habitats exist in
what woodland is present. An even larger number of possible woodland
habitats is clearly missing, however, because the 101 Kansan species
actually represent but 44 per cent of all woodland birds in North
America, according to Udvardy's analysis. Broad-leaved, deciduous
woodlands in Kansas are of restricted horizontal and vertical
stratification. More complex deciduous forest associations and all
coniferous forest associations are absent from the State.
Using Mayr's (1946) breakdown of geographical origin of the North
American bird fauna, about 53 per cent of the woodland passerine birds
in Kansas are of "North American" origin, 22 per cent are of "Eurasian"
origin, and 14 per cent are of "South American" origin (Table 3). These
figures for Kansas are commensurate with those found for other
geographic districts at the same latitude in North America (Mayr,
1946:28). Other characteristics of woodland birds are summarized in
tables 4 and 5.
TABLE 3.--ANALYSIS OF ECOLOGIC GROUPS OF BIRDS BY STATUS OF
RESIDENCY AND AREA OF ORIGIN
Column headings:
A: Migrant E: N. Amer.
B: Resident F: S. Amer.
C: Pt. Migr. G: Unanalyzed
D: Old World
==========================+=====+=====+=====+=====+======+=====+=====
| A | B | C | D | E | F | G
--------------------------+-----+-----+-----+-----+------+-----+-----
Woodland species, 101:58% | 60% | 29% | 11% | 22% | 53% | 14% | 11%
Limnic species, 36:21% | 94% | 0 | 6% | 0 | 14% | 0 | 86%
Grassland species, 23:13% | 61% | 26% | 13% | 9% | 56% | 3% | 30%
Xeric Scrub species, 3:2% | 33% | 66% | 0 | 0 | 100% | 0 | 0
Unanalyzed species, 11:6% | 64% | 27% | 9% | 26% | 26% | 0 | 48%
--------------------------+-----+-----+-----+-----+------+-----+-----
_Limnic Habitats_
Of Kansan birds, 36 species (20 per cent) prefer limnic habitats (Table
1). Udvardy found this group to represent 15 per cent of the North
American avifauna. Kansas is not notably satisfactory for limnic
species, and only 38 per cent of the total North American limnic
avifauna is present in the State.
Thirty-one species of limnic birds belong to families that Mayr (1946)
considered to be unanalyzable as to their geographic origin; of the five
remaining species, all seem to be of North American origin. Other
characteristics of limnic birds are summarized in tables 4 and 5.
_Grassland Habitats_
Twenty-three species of our total can be called grassland species (Table
1). The subtotal is less than one-fifth of the Kansan avifauna, but it
represents 72 per cent of the grassland birds of North America;
grassland habitats abound in Kansas. Only 5.3 per cent of all North
American birds are grassland species (Udvardy, 1958).
About 56 per cent of these birds are of North American stocks, nine per
cent of Eurasian stocks, and three per cent of South American stocks.
The percentage of North American species is the greatest for any habitat
group here considered. Other characteristics of grassland birds are
summarized in tables 4 and 5.
TABLE 4.--ANALYSIS BY HABITAT-TYPE AND RESIDENCY STATUS OF
HISTORIC AVIAN STOCKS IN KANSAS
Column Headings:
A: Woodland E: Unanal. Hab.
B: Limnic F: Migrant
C: Grassland G: Resident
D: Xeric Scrub H: Partly Migrant
=======================+=====+=====+=====+=====+=====+=====+=====+=====
| A | B | C | D | E | F | G | H
-----------------------+-----+-----+-----+-----+-----+-----+-----+-----
Old World Element | 80% | 0 | 8% | 0 | 12% | 11% | 78% | 11%
27:16% | | | | | | | |
North American Element | 69% | 6% | 17% | 4% | 4% | 72% | 14% | 14%
77:44% | | | | | | | |
South American Element | 93% | 0 | 7% | 0 | 0 | 93% | 7% | 0
15:8% | | | | | | | |
Unanalyzed Origin | 22% | 56% | 13% | 0 | 9% | 79% | 16% | 5%
53:32% | | | | | | | |
-----------------------+-----+-----+-----+-----+-----+-----+-----+-----
_Xeric-Scrub Habitats_
Three species of Kansan birds can be placed in this category (Table 1).
This is less than one per cent of the North American avifauna, two per
cent of the Kansan avifauna, and ten per cent of the birds of xeric
scrub habitats in North America. The three species are considered to be
of North American origin.
_Unanalyzed as to Habitat_
Eleven species of Kansan birds could not be assigned to any of the
habitat-types mentioned above. The total represents two per cent of the
North American avifauna, six per cent of the birds of Kansas, and 55 per
cent of the species reckoned by Udvardy (_loc. cit._) to be
unanalyzable. Fifty-five per cent is a large fraction, but only to be
expected: species are considered unanalyzable if they show a broad,
indiscriminate use of more than one habitat-type, and such birds tend to
be widely distributed.
TABLE 5.--ANALYSIS BY ECOLOGIC STATUS AND AREA OF ORIGIN OF
MIGRANT AND RESIDENT BIRDS
Column headings:
A: Woodland F: Old World
B: Limnic G: North America
C: Grassland H: South America
D: Xeric Scrub I: Unanalyzed
E: Unanal. Hab.
=================+=====+=====+=====+=====+=====+=====+=====+=====+=====
| A | B | C | D | E | F | G | H | I
-----------------+-----+-----+-----+-----+-----+-----+-----+-----+-----
Migrant species | 52% | 29% | 12% | 1% | 6% | 2% | 49% | 12% | 37%
117:67% | | | | | | | | |
Resident species | 73% | 0 | 15% | 5% | 7% | 51% | 26% | 2% | 21%
40:23% | | | | | | | | |
Partly migrant | 64% | 11% | 17% | 0 | 6% | 17% | 66% | 0 | 17%
17:10% | | | | | | | | |
-----------------+-----+-----+-----+-----+-----+-----+-----+-----+-----
Species Reaching Distributional Limits in Kansas
The distributional limits of a species are useful in indicating certain
of its adaptive capacities and implying maintenance of or shifts in
characteristics of habitats. Although it is generally an
oversimplification to ignore abundance when treating of distribution,
the present remarks of necessity do not pertain to abundance.
TABLE 6.--BREEDING BIRDS REACHING DISTRIBUTIONAL LIMITS IN KANSAS
Species reaching northern distributional limits
_Florida caerulea_ _Geococcyx californianus_
_Leucophoyx thula_ _Caprimulgus carolinensis_
_Coragyps atratus_ _Muscivora forficata_
_Elanoides forficatus_ _Parus carolinensis_
_Ictinia misisippiensis_ _Vireo atricapillus_
_Tympanuchus pallidicinctus_ _Passerina ciris_
_Callipepla squamata_ _Aimophila cassinii_
Species reaching southern distributional limits
_Aythya americana_ _Empidonax minimus_
_Parus atricapillus_ _Steganopus tricolor_
_Bombycilla cedrorum_ _Chlidonias niger_
_Dolichonyx oryzivorus_ _Coccyzus erythropthalmus_
_Pedioecetes phasianellus_
Species reaching eastern distributional limits
_Eupoda montana_ _Corvus cryptoleucus_
_Numenius americanus_ _Salpinctes obsoletus_
_Phalaenoptilus nuttallii_ _Icterus bullockii_
_Colaptes cafer_ _Pheucticus melanocephalus_
_Tyrannus verticalis_ _Passerina amoena_
_Sayornis saya_
Species reaching western distributional limits
_Aix sponsa_ _Vireo griseus_
_Buteo platypterus_ _V. flavifrons_
_Philohela minor_ _Mniotilta varia_
_Ectopistes migratorius_ _Protonotaria citrea_
_Conuropsis carolinensis_ _Parula americana_
_Chaetura pelagica_ _Dendroica discolor_
_Archilochus colubris_ _Seiurus motacilla_
_Dryocopus pileatus_ _Oporornis formosus_
_Centurus carolinus_ _Wilsonia citrina_
_Myiarchus crinitus_ _Setophaga ruticilla_
_Empidonax virescens_ _Sturnella magna_
_E. traillii_ _Piranga olivacea_
_Parus bicolor_ _Pheucticus ludovicianus_
_Thryothorus ludovicianus_ _Pipilo erythrophthalmus_
_Cistothorus platensis_ _Passerherbulus henslowii_
_Hylocichla mustelina_
_Western Limits Reached in Kansas_
Thirty-one species (tables 6 and 7) reach the western limits of their
distribution somewhere in Kansas. Most of these limits are in eastern
Kansas, and coincide with the gradual disappearance of the eastern
deciduous forest formation. Twenty-nine species are woodland birds, and
few of these seem to find satisfactory conditions in the riparian woods
extending out through western Kansas. The Wood Thrush is the one
woodland species that has been found nesting in the west (Decatur
County; Wolfe, 1961). Descriptively, therefore, the dominant reason for
the existence of distributional limits in at least 28 of these birds is
the lack of suitable woodland in western Kansas; these 28 are the
largest single group reaching distributional limits in the State. Many
other eastern woodland birds occur in western Kansas along riparian
woodlands, as is mentioned below.
Two species showing western limits in Kansas are characteristic of
grassland habitats; the Eastern Meadowlark seems to disappear with
absence of moist or bottomland prairie grassland and the Henslow Sparrow
may be limited westerly by disappearance of tall-grass prairie.
The Short-billed Marsh Wren, a marginal limnic species, reaches its
southwesterly mid-continental breeding limits in northeastern Kansas.
The species breeds in Kansas in two or three years of each ten, in
summers having unusually high humidity.
_Northern Limits Reached in Kansas_
Fourteen species (tables 6 and 7) reach their northern distributional
limits in Kansas. Eight of these are birds of woodland habitats, but of
these only the Carolina Chickadee is a species of the eastern deciduous
woodlands; the other seven live in less mesic woodland. Three of these
species (Chuck-will's-Widow, Scissor-tailed Flycatcher and Painted
Bunting) have breeding ranges that suggest the northwesterly occurrences
of summer humid warm air masses ("gulf fronts") and this environmental
feature perhaps is of major importance for these birds, as it is also
for the vegetational substratum in which the birds live.
The Lesser Prairie Chicken and the Cassin Sparrow are the two birds of
grasslands that are limited northerly in Kansas. Xeric, sandy grassland
is chiefly limited to the southwestern quarter of Kansas, and this
limitation is perhaps of major significance to these two species. The
Scaled Quail and Roadrunner tend to drop out as the xeric "desert scrub"
conditions of the southwest drop out in Kansas.
TABLE 7.--ANALYSIS BY HABITAT-TYPE OF BIRDS REACHING
DISTRIBUTIONAL LIMITS IN KANSAS
========================+===============================================
| Habitat-types
DIRECTIONAL +----------+-----------+--------+-------+-------
LIMIT | | | | Xeric |
| Woodland | Grassland | Limnic | Scrub | Total
------------------------+----------+-----------+--------+-------+-------
Western extent | 28 | 2 | 2 | 0 | 31
Northern extent | 8 | 2 | 2 | 2 | 14
Eastern extent | 6 | 4 | 0 | 2 | 11
Southern extent | 4 | 2 | 3 | 0 | 9
+----------+-----------+--------+-------+-------
Totals | 46 | 10 | 6 | 3 | 65
| | | | |
Per cent of the Species | | | | |
in Stated Habitat | 46 | 43 | 14 | 100 | 37
------------------------+----------+-----------+--------+-------+-------
_Eastern Limits Reached in Kansas_
Eleven species (tables 6 and 7) reach their eastern distributional
limits in Kansas. Six of these are woodland birds. Four of these are
members of well-known species-pairs: the Red-shafted Flicker, Bullock
Oriole, Black-headed Grosbeak, and Lazuli Bunting. Presence to the east
of complementary species has much to do with the absence of these
species in eastern Kansas. Four of the eleven are birds of grasslands,
and they drop out as the short-grass prairie is restricted easterly.
The Rock Wren may be considered characteristic of xeric scrub in Kansas,
and it is not found to the east in the absence of such scrub.
_Southern Limits Reached in Kansas_
Eight species (tables 6 and 7) reach their southern distributional
limits in Kansas. Half of these birds are of woodland habitats, and of
these four, the Black-capped Chickadee and Cedar Waxwing are chiefly of
sub-boreal distribution. The Black-capped Chickadee also finds its niche
partly pre-empted in southern Kansas by the Carolina Chickadee.
The Bobolink and Sharp-tailed Grouse are grassland species that are
seemingly adapted to cooler, dryer grassland than is found in most of
Kansas.
The Redhead, Wilson Phalarope, and Black Tern are limnic species,
perhaps limited southerly by high summer temperatures; the three species
are entirely marginal anywhere in Kansas.
TABLE 8.--BIRDS OF THE EASTERN DECIDUOUS FOREST FOUND IN
WESTERN KANSAS IN RIPARIAN WOODLAND
_Accipiter cooperii_[C]
_Coccyzus americanus_[C]
_Centurus carolinus_
_Melanerpes erythrocephalus_
_Tyrannus tyrannus_
_Myiarchus crinitus_
_Contopus virens_
_Sayornis phoebe_
_Cyanocitta cristata_
_Dumetella carolinensis_
_Toxostoma rufum_
_Sialia sialis_
_Vireo olivaceus_
_Icterus spurius_[C]
_Icterus galbula_
_Quiscula quiscalus_
_Piranga rubra_[A]
_Passerina cyanea_
_Richmondena cardinalis_
_Pipilo erythrophthalmus_[C]
_Spizella passerina_[C]
[C] Breeds farther west in North America in other types of
vegetation.
_Influence of Riparian Woodland_
Although the largest single element of the Kansan avifauna that reaches
distributional limits in Kansas is made up of birds of the eastern
deciduous forest, several species of the eastern woodlands are present
in Kansas along the east-west river drainages in riparian woodland; the
species are listed in Table 8. Twenty-one kinds are involved if we
include the Cooper Hawk, Yellow-billed Cuckoo, Orchard Oriole, Summer
Tanager, Rufous-sided Towhee, and Chipping Sparrow, all of which breed
farther to the west but are present in western Kansas only along river
drainages. This leaves 15 species of eastern deciduous woodlands that
occur west in Kansas along riparian woodland (_versus_ 30 species that
drop out chiefly where eastern woodland drops out). These 15 species are
about one-third of all woodland birds in western Kansas. Riparian
woodland does not seem to afford first-rate habitat for most of the
eastern woodland species that do occur; breeding density seems to be
much lower than in well-situated eastern woodland.
The importance of these linear woodlands as avenues for gene-flow
between eastern and western populations, especially of species-pairs
(grosbeaks, flickers, orioles, and buntings), is obviously great.
Likewise significant is the existence of these alleys for dispersal from
the west of certain species (for instance, the Black-billed Magpie and
the Scrub Jay) into new but potentially suitable areas.
BREEDING SEASONS
Introduction
An examination of breeding seasons or schedules is properly undertaken
at several levels. The fundamental description of variation in breeding
schedules must itself be detailed in several ways and beyond this there
are causal factors needing examination. The material below is a summary
of the information on breeding schedules of birds in Kansas, treated
descriptively and analytically in ways now thought to be of use.
Almost any event in actual reproductive activity has been used in the
following report; nestbuilding, egg-laying, incubation, brooding of
young, feeding of young out of the nest are considered to be of equal
status. To any such event days are added or subtracted from the date of
observation so as to yield the date when the clutch under consideration
was completed.
Such corrected dates can be used in making histograms that show the time
of primary breeding activity, or the "egg-season." All such schedules
are generalizations; data are used for a species from any year of
observation, whether 50 years ago or less than one year ago. One
advantage of such procedure is that averages and modes are thus more
nearly representative of the basic temporal adaptations of the species
involved, as is explained below.
When information on the schedule of a species from one year is lumped
with information from another year or other years, two (and ordinarily
more than two) frequency distributions are used to make one frequency
distribution. The great advantage here is that the frequency
distribution composed of two or more frequency distributions is more
stable than any one of its components. Second, the peak of the season,
the mode of egg-laying, is represented more broadly than it would have
been for any one year alone. Third, the extremes of breeding activity
are fairly shown as of minute frequency and thus of limited importance,
which would not be true if just one year were graphed. All these
considerations combine to support the idea that general schedules in
fact represent the basic temporal adaptations of a species much better
than schedules for one year only.
Variation in Breeding Seasons
In the chronology of breeding seasons of birds, there are three basic
variables: time at which seasons begin, time at which seasons end, and
time in which the major breeding effort occurs. These variables have
been examined in one population through time (Lack, 1947; Snow, 1955;
Johnston, 1956), in several populations of many species over wide
geographic ranges (Baker, 1938; Moreau, 1950; Davis, 1953), and in
several populations of one species (Lack, _loc. cit._; Paynter, 1954;
Johnston, 1954). The analysis below is concerned with breeding of many
kinds of birds of an arbitrarily defined area and with the influence of
certain ecologic and zoogeographic factors on the breeding seasons for
those several species.
THE INFLUENCE OF SEASONAL STATUS.--Here we are interested in whether a
species is broadly resident or migrant in Kansas; 70 species are
available for analysis.
_Resident Species_
Twenty-four species, furnishing 875 records of breeding, are here
considered to be resident birds in northeastern Kansas. These species
are Cooper Hawk, Red-tailed Hawk, Prairie Chicken, Bobwhite, Rock Dove,
Great Horned Owl, Red-bellied Woodpecker, Hairy Woodpecker, Downy
Woodpecker, Horned Lark, Blue Jay, Common Crow, Black-billed Magpie,
Black-capped Chickadee, Tufted Titmouse, Carolina Wren, Bewick Wren,
Mockingbird, Eastern Bluebird, Loggerhead Shrike, Starling, House
Sparrow, Eastern Meadowlark, and Cardinal. The distribution of completed
clutches (Fig. 1) runs from mid-January to mid-September, with a modal
period in the first third of May. Conspicuous breeding activity occurs
from mid-April to the first third of June.
_Migrant Species_
Forty-six species, furnishing 2,522 records of breeding, are considered
to be migrant in northeastern Kansas. These species are Great Blue
Heron, Green Heron, Swainson Hawk, American Coot, Killdeer, Upland
Plover, American Avocet, Least Tern, Yellow-billed Cuckoo, Black-billed
Cuckoo, Burrowing Owl, Common Nighthawk, Chimney Swift, Red-headed
Woodpecker, Eastern Kingbird, Western Kingbird, Scissor-tailed
Flycatcher, Great Crested Flycatcher, Eastern Phoebe, Eastern Wood
Pewee, Bank Swallow, Rough-winged Swallow, Barn Swallow, Purple Martin,
Brown Thrasher, Catbird, House Wren, Robin, Wood Thrush, Blue-gray
Gnatcatcher, Bell Vireo, Warbling Vireo, Prothonotary Warbler, Yellow
Warbler, Chat, Western Meadowlark, Red-winged Blackbird, Orchard Oriole,
Baltimore Oriole, Common Grackle, Black-headed Grosbeak, Indigo Bunting,
Dickcissel, Lark Sparrow, and Field Sparrow. The distribution of
completed clutches runs from mid-March to the first third of September,
with a modal period of egg-laying in the first third of June (Fig. 1).
Conspicuous breeding activity occurs from the first third of May to the
last third of June.
THE INFLUENCE OF DOMINANT FORAGING ADAPTATION.--Five categories here
considered reflect broad foraging adaptation: woodland species, taking
invertebrate foods in the breeding season from woody vegetation or the
soil within wooded habitats; grassland species, taking invertebrate
foods in the breeding season from within grassland situations; limnic
species, foraging within marshy or aquatic habitats; aerial species,
foraging on aerial arthropods; raptors, feeding on vertebrates or large
insects.
_Raptors_
Six species, furnishing 174 records of breeding, are here considered, as
follows: Cooper Hawk, Red-tailed Hawk, Swainson Hawk, Great Horned Owl,
Burrowing Owl, and Loggerhead Shrike. The distribution of clutches (Fig.
1) runs from mid-January to the first third of July and is bimodal. One
period of egg-laying occurs in mid-February and a second in the last
third of April. Such a distribution indicates that two basically
independent groups of birds are being considered. The first peak of
laying reflects activities of the large raptors, and the second peak is
that of the insectivorous Burrowing Owl and Loggerhead Shrike. The peak
for these two birds is most nearly coincident with that for grassland
species, a category to which the Burrowing Owl might well be relegated.
[Illustration: FIG. 1.--Histograms representing breeding
schedules of ten categories of Kansan birds. Heights of columns
indicate percentage of total of clutches of eggs, and widths
indicate ten-day intervals of time, with the 5th, 15th, and
25th of each month as medians. The occurrences of monthly means
of temperature and precipitation are indicated at the bottom of
the figure.]
_Limnic Species_
Six species, the Great Blue Heron, Green Heron, American Coot, American
Avocet, Least Tern and Red-winged Blackbird, furnish 264 records of
breeding. The distribution of clutches (Fig. 1) runs from mid-March to
the last third of July and is bimodal. This is another heterogeneous
assemblage of birds; the Great Blue Heron is responsible for the first
peak, in the first third of April. The other five species, however, show
fair consistency and their peak of egg-laying almost coincides with
peaks for aerial foragers, woodland species, and migrants, considered
elsewhere in this section.
_Grassland Species_
Ten species, Greater Prairie Chicken, Bobwhite, Killdeer, Upland Plover,
Horned Lark, Starling, Eastern Meadowlark, Western Meadowlark, Common
Grackle, and Dickcissel, furnish 404 records of breeding activity. The
distribution of clutches (Fig. 1) runs from the first of March to
mid-September. The peak of egg-laying occurs in the first third of May.
This is coincident with the peak for resident species, perhaps a
reflection of the fact that half the species in the present category are
residents in northeastern Kansas.
_Woodland Species_
In this category are included species characteristic of woodland edge.
Thirty-four species, furnishing 1,882 records of breeding, are here
treated: Yellow-billed Cuckoo, Black-billed Cuckoo, "flicker" (includes
birds thought to be relatively pure red-shafted, pure yellow-shafted, as
well as clear hybrids), Red-bellied Woodpecker, Red-headed Woodpecker,
Hairy Woodpecker, Downy Woodpecker, Blue Jay, Black-billed Magpie,
Common Crow, Black-capped Chickadee, Tufted Titmouse, Carolina Wren,
Bewick Wren, House Wren, Brown Thrasher, Catbird, Mockingbird, Robin,
Wood Thrush, Eastern Bluebird, Blue-gray Gnatcatcher, Bell Vireo,
Warbling Vireo, Prothonotary Warbler, Yellow Warbler, Chat, Orchard
Oriole, Baltimore Oriole, Cardinal, Black-headed Grosbeak, Indigo
Bunting, Lark Sparrow, and Field Sparrow. The distribution of clutches
runs from the first third of March to mid-September (Fig. 1). The modal
period for completed clutches is the first third of June. Conspicuous
breeding activity occurs from the first third of May to mid-June. The
distribution of the season in time is almost identical with that for
migrant species, reflecting the large number of migrant species in
woodland habitats in Kansas.
_Aerial Foragers_
Twelve species, Common Nighthawk, Chimney Swift, Eastern Kingbird,
Western Kingbird, Scissor-tailed Flycatcher, Great Crested Flycatcher,
Eastern Phoebe, Eastern Wood Pewee, Bank Swallow, Rough-winged Swallow,
Barn Swallow, and Purple Martin, furnish 587 records of breeding. The
distribution of clutches (Fig. 1) extends from the last third of March
to the first third of August, and the modal date of clutches is in the
first third of June. Conspicuous breeding activity occurs from the end
of May to the end of June. The peak of nesting essentially coincides
with that characteristic of migrants.
Zoogeographic Categories
Three categories of Mayr (1946) are of use in analyzing trends in
breeding schedules of birds in Kansas. These categories of presumed
ultimate evolutionary origin are the "Old World Element," the "North
American Element," and the "South American Element." Not always have I
agreed with Mayr's assignments of species to these categories, and such
differences are noted. There is some obvious overlap between these
categories and those discussed previously.
_Old World Element_
Eighteen species, Red-tailed Hawk, Rock Dove, Great Horned Owl, Hairy
Woodpecker, Downy Woodpecker, Black-billed Magpie, Common Crow,
Black-capped Chickadee, Tufted Titmouse, Robin, Loggerhead Shrike,
Starling, House Sparrow, Bank Swallow, Barn Swallow, and Blue-gray
Gnatcatcher, furnish 969 records of breeding (Fig. 1). Species for which
I have records but which are not here listed are the Blue Jay and the
Wood Thrush, both of which I consider to be better placed with the North
American Element. The distribution of completed clutches runs from
mid-January to the first third of August, and shows a tendency toward
bimodality. The second, smaller peak is due to the inclusion of
relatively large samples of three migrant species (Robin, Bank Swallow,
and Barn Swallow). The timing of the breeding seasons of these three
species is in every respect like that of most other migrants; if they
are removed from the present sample the bimodality disappears,
indicating an increase in homogeneity of the unit.
_North American Element_
Twenty-six species, Greater Prairie Chicken, Bobwhite, "flicker,"
Rough-winged Swallow, Purple Martin, Blue Jay, Carolina Wren, Bewick
Wren, House Wren, Mockingbird, Catbird, Brown Thrasher, Wood Thrush,
Bell Vireo, Warbling Vireo, Prothonotary Warbler, Yellow Warbler, Chat,
Eastern Meadowlark, Western Meadowlark, Red-winged Blackbird, Orchard
Oriole, Baltimore Oriole, Common Grackle, Lark Sparrow, and Field
Sparrow, furnish 1,233 records of breeding (Fig. 1). The distribution of
completed clutches runs from the first third of April to the first third
of September. The modal date for completion of clutches is June 1.
_South American Element_
Twelve species, Eastern Kingbird, Western Kingbird, Scissor-tailed
Flycatcher, Great Crested Flycatcher, Yellow-bellied Flycatcher, Traill
Flycatcher, Eastern Wood Pewee, Eastern Phoebe, Cardinal, Black-headed
Grosbeak, Rose-breasted Grosbeak, and Indigo Bunting, furnish 552
records of breeding (Fig. 1). The curve representing this summary
schedule is bimodal, wholly as a result of including the Eastern Phoebe
and the Cardinal with this sample.
_Relationship of Schedules to Temperature and Precipitation_
In outlining the ten categories above, attention has been given to
certain similarities and differences in the frequency distributions. A
slightly more refined way of comparing the frequency distributions is to
relate them to other, seasonally variable phenomena. Figure 1 shows the
frequency distributions of egg-laying of these ten categories of birds
in terms of the regular changes in mean temperature and mean
precipitation characteristic of the environments in which these birds
live in the breeding season.
Table 9 shows that there are two basic groups of birds according to peak
of egg-laying and incidence of precipitation; raptors, birds of Eurasian
origin, resident birds, and birds of grassland habitats tend to have
their peaks of egg-laying prior to the peak of spring-summer rains, and
the other six categories tend to have their peaks of egg-laying occur in
the time of spring-summer rains. Regarding temperature, there are four
categories of birds; these are evident in the table.
Some of the correspondences deserve comment. Residents and grassland
species both breed before the rains come and before mean temperatures
reach 70 deg.F., and this correspondence probably results from most of the
grassland species being residents. Contrariwise, most birds of Eurasian
stocks are residents, but not all residents are of such stocks; the two
groups are discrete when mean temperature at breeding is considered.
Woodland birds, aerial foragers, and birds of South American
evolutionary stocks breed after temperatures surpass 70 deg.F. on the
average. Almost all such species are migrants, but many migrants have
different temporal characteristics, and the categories thus are shown to
be discrete on the basis of temperature at time of breeding.
The change through spring and summer of temperature and precipitation
delineates the inception and waxing of the growing season of vegetation
and of the subsequent arthropod populations, on which most of the birds
feed in the breeding season. The temporal characteristics of growing
seasons in North America have been treated by Hopkins (1938) and have
been related to timing of breeding seasons in Song Sparrows (_Passerella
melodia_) of the Pacific coast of North America (Johnston, 1954).
Significance of Phylogeny to Breeding Schedules
Evidence from a variety of sources demonstrates that timing of breeding
seasons is either broadly or specifically genetically-determined. For
some species in some situations major environmental variables are
paramount in regulating timing of breeding, but in others the innate,
regulatory "clock" is less closely tied to conspicuous exogenous
stimuli. The work by Miller (1955a, 1955b, 1960) with several species of
_Zonotrichia_ strongly indicates that endogenous timing is most
important for these birds, and there is ecological evidence for Song
Sparrows that supports the same point (Johnston, 1954, 1956). It is, in
any event, possible to treat breeding schedules as species-specific
characters, for any one geographic area.
In an attempt to relate a breeding schedule to previous ancestral modes,
that is by extension to phylogeny, it is necessary to know how often
ancestral adaptations can persist in the face of necessity to adapt to
present environmental conditions. It is necessary to know how
conservative or how immediately plastic breeding schedules can be. The
disadvantage of using available information about configurations of
breeding seasons (as shown in Figs. 3 to 9) is that it is extremely
difficult to compare visually at one time more than six or eight
histograms as to the trenchant similarities and differences regarding
times of inception and cessation of breeding, and time of peak
egg-laying. It is possible, however, to reduce these three variables to
one variable (as described below), which allows the necessary
comparisons to be made more easily; this variable may be called the
_breeding index_.
_Calculation of Breeding Index_
The chronological year is broken roughly into ten-day intervals numbered
1 to 36. The histogram describing the temporal occurrence of the
breeding season of a species in our area usually will lie within
intervals 7 to 25. The modal date for completion of clutches is given a
value corresponding to the number of ten-day intervals beyond interval
7 (March 1-10); this describes the modal variable. The date of
completion of 83 per cent of all clutches is given a value corresponding
to the number of ten-day intervals it lies from interval 11 (April
11-20); this describes the 83 per cent variable (and is a measure of the
length of the season in terms of its inception). The breeding index can
then be calculated as follows:
I = X_{m} + X_{sd},
where: I is the breeding index,
X_{m} is the modal variable, and
X_{sd} is the 83 per cent variable.
This is obviously an arbitrary scheme to gain a simple measure of
beginning, peak, and end of a breeding season. Other schemes could be
devised whereby different absolute values would be involved, but the
relative nature of the results would be preserved. The values under the
present system for 73 species of Kansan birds run from -5 to +22; early
modal dates and cessation to breeding give low values, late dates high
values.
Within this framework there are other, presumably subordinate, factors
that influence the values of breeding indices, as follows:
1. Migratory habit. Any migrant tends to arrive on breeding grounds
relatively late, hence migrants ordinarily have higher index values than
do residents.
2. Colonial breeding. The strong synchrony of colonially-breeding
species tends to move the modal egg-date toward the time of inception of
breeding; as a result colonially-breeding species probably have lower
index values than they would have if not colonial.
3. Single-broodedness. Species having only one brood per season tend to
have shorter seasons than double-brooded species, and their index values
tend to be lower than those of double-brooded species.
Migratory habit unquestionably has considerable influence on index
values in some species. It is not, however, as important as other
matters, such as the condition of the food substratum or sensitivity of
the pituitary-gonadal mechanism, in determining timing and mode of
breeding activity. The schedule of the Purple Martin is the extreme
example showing that time of spring arrival on breeding grounds is not
necessarily related to time of inception of breeding. It should be
emphasized that the factors leading to northward migratory movement may
be involved in timing of the annual gonadal and reproductive cycle.
Figure 2 presents a graphic summary of values of breeding indices for
many groups of Kansan birds. The values for species of a given family
have been linked by a horizontal line. The length of this line is
proportional to the degree to which the index values for the species
concerned resemble one another. Note that the plottings for the Picidae,
Corvidae, Turdidae, Tyrannidae, and Icteridae each contain one point
that is well-removed from a cluster of points. This can be interpreted
as a measure of the frequency of adaptive plasticity versus adaptive
conservatism; five of the 24 plottings show a plastic character, 19 a
conservative. There are 26 plottings that show temporal consistency, all
of which may be taken as evidence of adaptive (or relictual)
conservatism of the species in question.
[Illustration: FIG. 2.--Breeding indices for Kansan birds.
Vertical hash-marks indicate the value of breeding index for a
given species; horizontal lines show the range of values of
breeding index for families and orders.]
_Conclusion_
Such patterns of breeding chronology support the idea that seasonal
response to the necessities of breeding is conservative more often than
plastic. Most students of breeding schedules believe that since these
are highly adaptive, they must also be capable of flexibility to meet
variable environments within the range of the species. Such thinking
receives support when different geographic localities are considered for
one species (Johnston, 1954), or when specific features of a special
environment are considered (see Miller, 1960; Johnston, 1956).