Bearing variations in plumage, song, and migratory habits, Common Yellowthroats of different subspecies together occupy large portions of North America during the nesting season. Disagreement over the subspecific taxonomy of Common Yellowthroats remains, though at least one race from south Texas numbers only in the low hundreds of individuals and is of significant conservation concern.
Common Yellowthroats are vulnerable to many of the usual predators that seek birds, such as raptors and mammals. Among the more unusual reports of mortality in Common Yellowthroats are several examples of being caught in spider webs, and one instance of a yellowthroat being found in the stomach of a largemouth bass.
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Description of the Common Yellowthroat
The Common Yellowthroat has greenish-brown upperparts and a yellow throat.
Males have a wide, black mask across each cheek and the forehead, with a white line bordering the upperside of the mask. Length: 15 in. Wingspan: 7 in.
Visit the Bent Life History for additional information.
Females have a mostly greenish-brown head with no black or white markings.
Seasonal change in appearance
Fall birds are similar to spring birds but have brownish flanks.
Fall immatures are very plain, with males having only partially black cheeks.
Common Yellowthroats inhabit marshes, swamps, and wet thickets.
Common Yellowthroats eat insects.
Common Yellowthroats forage near the ground in dense vegetation.
Common Yellowthroats breed across much of southern Canada and the U.S. They winter from the southern U.S. south to South America. The population has declined slightly in recent decades.
Bent Life History
Visit the Bent Life History for extensive additional information on the Common Yellowthroat.
The Common Yellowthroat female often runs underneath vegetation for some distance when leaving the nest, making nests difficult to locate.
The Common Yellowthroat is one of the most widespread and abundant warblers in North America.
The song is a series of “wichity-witchity-witch” notes. A hard “chep” call is also given.
Will visit water features.
Kentucky Warbler males have a yellow supercilium and a black patch only below the eye. Common Yellowthroats are smaller and have longer tails than Oporornis warblers.
The female Yellow Warbler is a more uniform yellow. The male, shown here, has red streaks on the chest.
The Common Yellowthroat’s nest is a cup of leaves, grasses, and moss and is lined with finer materials. It is placed low in weeds or grass.
Number: Usually lay 3-5 eggs.
Color: Whitish with darker markings.
Incubation and fledging:
The young hatch at about 12 days and fledge at about 8-10 days, though remaining dependent on the adults for some time.
Bent Life History of the Common Yellowthroat
Published by the Smithsonian Institution between the 1920s and the 1950s, the Bent life history series of monographs provide an often colorful description of the birds of North America. Arthur Cleveland Bent was the lead author for the series. The Bent series is a great resource and often includes quotes from early American Ornithologists, including Audubon, Townsend, Wilson, Sutton and many others.
Bent Life History for the Common Yellowthroat – the common name and sub-species reflect the nomenclature in use at the time the description was written.
GEOTHLYPSIS TRICHAS BRACHIDACTYLA (Swainson)
GEOTHLYPIS TRICHAS TRICHAS (Linnaeus)
While the following account applies primarily to the northern yellowthroat Geothlypsis trichas brachidactyla, for practical reasons it also includes the Maryland yellowthroat Geothlypsis trichas trichas, as the breeding and winter ranges overlap and the literature pertaining to these two forms is so intermixed that they are not easily separated.
The species of Geothlypis respond more readily to the influences of the environment than do other American warblers. As a result 12 subspecies of trichas have been recognized by the 1931 A. 0. U. Check List and subsequent supplements. Of these, 4, trichas, brachidactyla, ignota, and typhicola are in eastern United States and the other 8, occidentalis, campicola, sinuosa, chryseola, scirpicola, arizela, insperata, and modesta are represented in the western part of the country.
The color pattern of the 12 subspecies is similar; and they vary chiefly in minor differences of size and intensity of color. in a number of instances, the great individual variation which characterizes these birds so obscures their subspecific differences that determination of skins is often difficult and positive identification in the field, especially where the ranges overlap, is impossible.
Of the two forms included in this life history, the northern yellowthroat differs from the Maryland yellowthroat, in the male, in its larger size, and by reason of its more greenish upper surface, more whitish frontal band of grays, more extensively yellow posterior parts, and its usually brownish flanks. The female of the northern is similar to the Maryland but is larger, more greenish above, and slightly paler.
The breeding range of the northern yellowthroat extends from Newfoundland, Labrador and Quebec south to New Jersey, northern Pennsylvania and West Virginia, while that of the Maryland extends from southern Pennsylvania. south to eastern Texas and northern parts of Georgia and Alabama.
Throughout most of its breeding range the yellowthroat ranks as one of the abundant warblers. Because of the striking and easily recognized plumage of the male, especially the bright yellow throat and contrasting black mask, and its characteristic syllabic and easily memorized song it is one of our best-known birds. The modestly colored female is more difficult to identify, as it may be confused, by the beginner, with other similarly colored warblers. The yellowthroat seldom visits the habitation of man; it prefers wild lands, especially those grown up with briers and low brush. Its favorite nesting haunts are in the tangled vegetation of brook-sides or margins of swamp woodlands or among the grass and sedges of the marshes, where it frequently shares the company of such birds as the swamp sparrow and the marsh wrens.
When invading its haunts one is impressed with the vigorous personality of the male. lie nervously raises his alarm with a variety of scolding, interrogative chirps and chattering notes and his dark inquisitive eyes sparkle with excitement through the black masks.
He darts with nervous animation from place to place, then disappears in the dense cover only to appear again to denounce the intrusion. He displays many wrenlike characteristics, suggesting to Bartram the name olive-colored wren.
Although seemingly secretive and shy, they are unsuspecting and will often allow an approach to within a few feet of them. When finally convinced that no harm is meant, the male may even pour out his song from an elevated perch above his retreat, well-exposed to view. At times he will sing as he proceeds with his serious search for insects among the grass and shrubs.
Spring: Jt is impossible to separate the records on the migration of the subspecies of the yellowthroat occurring on the Atlantic coast. The earliest spring migrants appearing in Florida are said to be the Florida ~ellowthroat (ignota) whereas the northern (brachidactyla) follows at later dates. The earliest records for North Carolina have been reported as the Maryland yellowthroat (trickas). The matter ‘5 further complicated by the fact that southern representatives of the yellowthroat are almost non-migratory, being more or less permanent residents in Florida, whereas the northern yellowthroats which breed as far north as Newfoundland and Labrador pass over southern United States, going directly over the home of their southern relatives to spend the winter in the West Indies.
The earliest dates of its appearance at the Florida lighthouses occur during the first week in March, the numbers increase during April, and it is one of the few warblers that are common migrants in southern Florida during the month of May. The migration of the yellowthroat is thus one of the most extended.
The first yellowthroats arrive in North Carolina during the last week of March, by the middle of April they arrive in New Jersey and Maryland, and late in April they are in New York state. The first arrivals appear in southern New England during the first week of May, and the vanguard of northern yellowthroats can be expected in Maine before the middle of the month, although the bulk of the birds do not appear until a week or so later. They reach the northern limits of their nesting range in Newfoundland by the last week of May.
The subspecies brackid act yla~ according toE. C. Oberholser (1938), is a winter resident in Louisiana from October 8 to April 1. Records, presumably of the northern yellowthroat, reach Arkansas and Kentucky about the middle of April, and St. Louis, Mo., a few days later. They arrive in Ohio during the last week of April, Minnesota the first week of May, and by the middle of the month they are on their breeding grounds in North Dakota and Ontario. The progress of the birds on the Atlantic and Mississippi flyways during the spring migration is at approximately the same rate.
Nesting: Unlike many of our warbiers, the yellowthroat does not nest in the interior of our dense forests and is seldom seen in the upper branches of tall trees, being more or less restricted to low growths of vegetation. However, it is not strictly terrestrial in its habits, as in the ovenbird. It is partial to wet situations but these need not be great in extent. While it may be found on the borders of large marshes and especially on little islands in marshes and swamps it is also met with near springs and small brooks. An extreme- wet situation for a nesting site of the Maryland yellowthroat is described by W. I. Whitehill (1897) as follows: “While collecting in a large slough in Jackson County, Minnesota, on June 9, 1897, amid the green rushes where Long- and Short-billed Marsh Wrens were breeding, I ran across a pair of Yellow-throats * * * in some high rushes in about four feet of water, and upon investigating I found the nest placed almost level with the water in a thick clump of cat-tails, over fifty feet from shore, and right in the midst of a colony of Marsh Wrens.~~ Often individuals take up their residence in dry upland situations remote from water. They may be found along old fence rows grown up with weeds and tangles of briers and shrubbery, in huckleberry or raspberry or blackberry patches, and along the margins of woodlands and neglected country roadsides. Maurice Brooks (1940) reports that in the central Allegheny Mountain region where the spruces have been cut, the northern yellowthroats have invaded the highest mountains and are now abundant at all altitudes.
I have found it a very common nesting bird on many of the small outer islands off the coast of Maine. Some of these islands are without any source of fresh water and the only apparent attraction is a growth of rank grass and weeds and briers, and the extreme isolation from enemies, that such sites provide. For example, on Outer Green, a tiny islet of a few acres, there is a bit of tall grass and weeds only a few square yards in area, but it is sufficient to serve each year as the home of a pair of northern yellowthroats. On some of the larger islands where there is no fresh water other than rain I have seen as many as four pairs, all of which apparently were nesting.
The rest of the yellowthroat is frequently placed on or a few inches above the ground and is securely lodged in tussocks of grass, reeds, cattails, briers, and sometimes in herbaceous plants such as skunkcabbage and similar vegetation. Quite often the grass in which the nest is built is backed by a shrub or small tree. The nest is always well concealed from view until the grass or shrubs are parted. This in addition to the secretive habits of the birds makes the task of locating the nest most difficult. All I have seen were accidently found by flushing the bird from the nest when scouting through masses of vegetation in search of other birds.
Although the yellowthroat’s nest is commonly located on or within a few inches of the ground there are numerous instances in which the nest is secured to tall weed stalks or shrubs well above the ground. I. D. Campbell (1917) describes a nest of the Maryland yellowthroat that be found at Bernardsville, N. J., which was located in an alder, 3 feet above the ground. R. B. Simpson (1920) found a nest in the top of a cluster of laurels that was growing among a growth of hemlock trees. Mr. Simpson states that this nest was more like that of a mourning warbler than of a Maryland yellowthroat. William Brewster (1906) writes: “I have twice found it nesting in wound junipers in perfectly dry upland pastures near Arlington Heights” [Massachusetts]. Others have found nests in a diversity of situations indicating a great deal of individual variation as far as the selection of the nesting site is concerned.
One most unusual situation for a nest is described by A. W. Brockway (1899) of Old Lyme, Conn., as follows:
The locality chosen was near a back entrance to a house situated on the main street of town. A pair of shoes, which were the property of my friend, were placed outside of the door on the under pinning which projected out from the side of the house about two feet. One day he had occasion to wear them and went out and brought them into the house; * * * he discovered something in one of them, and upon examination found it to be a nest. The other shoe contained a few dry grasses and other fine material but for some reason the bird gave up the idea of building in that, and took up housekeeping in shoe No. 2. My friend immediately put the shoes back, thinking that she would return, and upon glancing into the shoe the next day was surprised to see that It contained an egg.
The yellowthroat continued laying until she had deposited five eggs.
P. G. Howes (1919) found a nest of the Maryland yellowthroat near his house in Stamford, Conn., which was effectively guarded by a nest of large hornets. According to Mr. Howes, the birds did not bother the wasps and the wasps respected the birds; a case of symbiosis.
The nests of the yellowthroat are not always isolated from others of their kind. For example Isaac U Hess (1910) found 17 nests in a half-acre swamp in central Illinois. This small swamp was in an extensively cultivated agricultural area, a region where suitable nesting sites are few in number. This unusual concentration of nesting birds was probably due to necessity rather than to choice.
The nest is a rather large, bulky structure composed of dead grass, weed stems, dead leaves, grape vine bark, dead ferns, etc. all loosely put together. The lining consists of fine grasses, tendrils, delicate fibers of bark, and often a quantity of hair.
The external parts of a nest, located in a meadow, was made up of wide blades of fresh grass lined with moss. Nests in cattail marshes had a foundation of cattail shreds, dried leaves, and grass stems and were lined with fine grasses only.
The nest is cup-shaped but in some instances loosely attached material extends above the main rim and may partially roof over the top of the structure. The average measurements of several typical nests, not including protruding materials, are outside diameter 31A inches, outside depth 3~/2 inches, inside diameter of the cup 13/4 inches, and its depth 11/2 inches.
All nests that I have seen were completed when found, and I have no information as to the time required or the manner in which the nest is built. The female apparently builds the nest~, buton one occasion I saw a male bird carrying nesting material and it is probable that he sometimes assists his mate in its construction.
Eggs: The usual set of the northern yellowthroat is four eggs but complete sets vary from three to five, and as many as six eggs have been reported. The eggs have a ground color of white or creamy white specked chiefly at the larger end with reddish brown, umber and black and with shell markings of stone gray. As in any large series of eggs of a species there is more or less variation from the typical. In some eggs the markings are in a distinct wreath near the larger end, in a few, some of the marks are in the form of small streaks and in still others the marks are faint and much reduced. The average size of two sets of four eggs each is .69 by .52 inch.
[AUTHOR’S NOTE: The measurements of 50 eggs of the northern yellowthroat average 17.5 by 13.3 millimeters; the eggs showing the four extremes measure 19.4 by 14.5, and 14.2 by 11.7 millimeters. The measurements of 26 eggs of the Maryland yellowthroat average 16.7 by 13.2 millimeters; the eggs showing the four extremes measure 18.3 by 13.8, 17.5 by 14.0, and 15.4 by 12.1 millimeters.]
Incubation: The incubation of the eggs requires 12 days and is performed entirely by the female. The male sings throughout the incubation period and is ever alert in defending his territory. He sometimes delivers foods to the female while she is incubating the eggs.
H. Mousley (1917) has found that although the eggs of different individual northern yellowthroats are subject to great variation, the successive sets of any one bird are strikingly alike in shape, size, and markings. Mr. Mousley did not succeed in getting the yellowthroat to lay a third set of eggs after the first two sets had been taken. It is doubtful if the yellowthroat rears more than two broods a year, Although Aretas A. Saunders (1938) believes that some of them do, since he has found the last birds leaving the nest in August. Usually an egg is laid each day until the set is completed but L. H. Porter (1908) reports finding a nest on June 4 in which the set of four eggs was not completed until June 12, a case, according to Porter, in which the deposit of the eggs was greatly prolonged by cold weather.
Unlike many birds, the northern yellowthroat usually leaves the nest unobtrusively when a human intruder comes near and does not betray its location by scolding. In the case of one nest the female sat very closely, and by exercising care I was able to almost touch her before she slipped off, mouse-fashion. She crept silently through the grass to the shelter of the neighboring vegetation and from there watched me intently. On another occasion the reaction of a yellowthroat was very different in respect to a small dog. Both birds made a wild demonstration, calling and scolding loudly and even making passes at the intruder in their efforts to drive him away from the vicinity of the nest.
The birds readily adapt themselves to a blind placed close to the nest, although their suspicions may be aroused at first. A day after the blind is in place they pay little attention to it, and I have had the bird return within 20 minutes after I had entered the structure.
Young: The young at the time of hatching are nearly naked, having only scant tufts of grayish or mouse-colored down on the crown and dorsal tracts of the body and wings. The eyes are sealed shut. Soon after emerging from the eggs the young are active and open wide their mouths in anticipation of food, which arrives before many minutes have elapsed. In one nest under observation the male delivered the first food in the form of a small, green insect larva. During the first day the male did the major part of the feeding, since the female remained at the nest much of the time to brood the delicate young. She was seen to leave the nest but twice during the first day, probably in search of food~ During the first few days the male frequently delivered food to the female at the nest, and she in turn fed it to the young.
By the third day the papillae of the developing feathers of the primaries, secondaries, and tertials, and to a minor degree those of the dorsal tract, have pierced the integument The remainder of the body remains naked except for the persisting tufts of down.
On the fourth day the eyes are open for the first time. The response of the young to the presence of the adults is much more marked than during the first days. Both male and female now share about equally in the arduous task of feeding the young, the food still consisting chiefly of insect larvae or soft-bodied adult insects. In feeding, at one nest I had under observation, the adult birds approached the nest silently, except for low twitters. They sneaked through the grass, selecting definite pathways more or less hidden by the vegetation, thus giving an observer little warning of their approach. The female did all of the brooding, but by the fourth day she spent less time at the nest and took more excursions in search of food.
The young usually emit a fecal sac after they are fed, and this is immediately seized by the parent that chances to be present. During the first few days the fecal sacs are usually eaten, but in later nest life they are more often carried a~vay some distance from the nest and dropped. I have seen the female eagerly keep watch for fully 5 minutes in anticipation of the fecal sac, even stimulating the youngsters with the tip of her bill to make them respond. The birds also removed all other foreign material such as a pellet of gum, small wads of paper, or rolled-up leaves purposely dropped into the nest as an experiment. The eggshells were removed at the time of hatching by the female. Nelle E. Shaver (1918) gives an interesting account of the removal of an addled egg as follows:
The nestlings bad crept to one side of the nest to escape the rays of the sun, so that the addled egg remained alone and in plain view. The male Yellow-throat came first to the nest with food. Seeing the addled egg he picked it up between the mandibles and carried it away, without breaking it and with no slips or unsuccessful trials. The bird, carrying the egg, disappeared in the foliage of the trees at a distance of about twenty-five feet from the nest. It is possible that the ridge formed by the shell fragment may have furnished a “grip” hy which the egg was firmly held In the mandibles. On the other hand, the mandibles are capable of opening to a surprising degree, and the whole behavior of the bird In this act seemed to proceed without uncertainty or experimentation.
This behavior is probably unusual, as in nests that I have had under observation the infertile egg remained until after the young normally left the nest.
By the fifth day the papillae of the larger feathers are bursting from their tips and this process is considerably advanced by the following day. At times the adult birds peck at the feathers apparently to facilitate the process of unsheathing. On the sixth day the young exhibit evidence of fear when a human observer examines the nest. The food delivered at this time consists of many adult insects such as small moths, spiders, beetles, and grasshoppers. A. C. Redfleld (1911) made a unique observation concerning the order in which the young are fed, as follows: “On one occasion the male fed two of the young. Before he had left the female arrived with an insect. He held his bill toward her as though wishing to take the food from her. Not heeding him she proceeded to feed the young one last favored by the male. Quickly her mate removed the food from the young one’s mouth and thrust it into the bill of the third young one, which had received nothing. This would make it appear that the parent birds do actually keep account of which young they have last fed.” Mr. Redfield’s interpretation may be correct, but it is rare for birds to exhibit such intelligence or to detect the sequence in which the young are fed.
By the eighth day the feathers have proceed~d in the unsheathing process to such an extent that the young present a smooth and pleasing contour. A few tufts of down, however, still cling to the ends of some of the contour feathers. Now that the young have a substantial protective covering and have acquired a temperature control, continuous brooding is not essential, but during extreme weather conditions, such as a cold rain or when the nest is exposed to the direct rays of the sun, the female protects the young by shielding them with her half-spread wings.
On the ninth day the young are ready to leave the nest and the least disturbance at the nest is a signal for them to leave. Under normal conditions they remain at the nest until the tenth day.
On June 10, 1945, I flushed a juvenal northern yellowthroat from the tall grass on Cone Island, off the coast of Maine. It flew but a few yards and alighted on a limb of a small dead shrub. The bird then allowed me to approach very near and exhibited not the least fear of my presence or that of the three other observers who stood nearby staring at the little creature. When we continued on our way the bird persisted in following us alighting again and again within a few feet of us. The youngster followed us in this manner for nearly a mile, until finally it joined company with an adult male, possibly its parent, and together they disappeared in the dense vegetation.
A. D. DuBois sends notes of his observations of a northern yellowthroat caring for a young cowbird and of its own young at Lincoln, Illinois, on June 21, 1913: “Found a female yellowthroat caring for a young cowbird which could fly very well and was about twice her own size. The cowbird flew to a bush near me. Its foster mother xvas nearby with food in her bill but she became agitated at my presence and flitted about, chirping. I suddenly clapped my hand over the young cowbird and thus caught it. The cowbird cried out with its squeaky voice and both male and female yellowthroats were immediately on the scene of the disturbance, fully as much concerned as though this young rascal were their own flesh and blood. The male, particularly, spread and fluttered his wings in a little bush 10 or 15 feet away, exhibiting great excitement, while the female chirped nervously from beneath a bush on the other side. They did not flutter along the ground as many birds do but remained in the weeds and bushes while doing all in their power to attract my attention. Sometimes the male held up his wings in a very pretty fashion. When I released the young cowbird it flew probably 100 feet, the foster mother following after it.
“Later, in the same bushy, weedy pasture, I caught a young yellowthroat, with much difficulty: a pretty little fellow much like the adult female, but with its tail just sprouting. I think this belonged to other parents. They made much less fuss about their own offspring than did the other pair about the young cowbird.”
The young are cared for by the adults for an unusually long period after they leave the nest, this being especially true of the second brood of the season, when parent birds may be seen feeding young that are able to fly as well as the adults, and apparently long after the young are capable of caring for themselves; in fact, they have been seen feeding their young up to the time of the fall migration. It is possible that the fall migration starts as a family group.
Plumages: The juvenal plumage which is acquired by a complete molt of the natal down is described by Dr. Dwight (1900) as follows: “Above, pale olive-brown of variable depth, greenish on the upper tail coverts. Wings olive-brown edged with olive-green, the median and greater coverts faintly tipped with cinnamon. Tail bright olivegreen. Below, tawny wood-brown, Naples-yellow on the abdomen and olive-yellow on the crissum. Inconspicuous orbital ring pale buff. Bill and feet pinkish buff becoming deep sepia with age.”
The following plumages of the Maryland yellowthroat are also described by Dr. Dwight: The first winter plumage is acquired “by a partial postjuvenal molt, beginning about the middle of July, which involves the body plumage and the wing coverts, but not the rest of the wings nor the tail.” It is unlike the previous plumage in being “above, deep olive-brown, greener on the upper tail coverts, the crown and forehead tinged with Mars-brown, the forehead frequently with a very few feathers black basally. The wing coverts chiefly olive-green. Below, bright lemon on the chin, throat and enssum, pale straw-yellow on the abdomen, the flanks washed with olive-brown, and a very faint buffy pectoral band.” Dr. Dwight notes that “the inalar and auricular regions show traces of the black mask varying from a few black feathers to a considerable area always veiled by ashy edgings. The black seldom invades the lores and f orehead and never the orbital ring as in the adult. The orbital ring is buffy white.”
The first nuptial plumage, he says, is acquired “by a partial prenuptial moult which involves chiefly the forehead, crown, sides of head and chin and not the rest of the plumage. These areas are somewhat worn, as a rule, when the birds reach New York in May, but specimens from Jamaica, West Indies, taken December 2nd, January 9th, 22d and 24th and February 4th show actual moult in progress. It is not surprising that the feathers assumed should show considerable wear before May. The black feathers of the ‘mask’ are acquired.”
He says that those of the upper margin of this area are broadly tipped with pearl-gray, which becomes ashy with wear. “This gray band, posteriorly on the crown, has its feathers tipped with Marsbrown and the basal black gradually diminishes more posteriorly as the extent of brown on each feather increasec. There is a yellow tinge in some of the feathers. The width of the band varies greatly. The bright yellow chin is also acquired and young birds and old become indistinguishable.”
The adult winter plumage is acquired “by a complete post-nuptial moult in July and August. It differs from the first winter dress in possessing a complete black ‘mask’, which includes the forehead, lores, orbital ring and auriculars, only the forehead and the auriculars being slightly veiled. The ‘mask’ has a distinct cinereous posterior border veiled on the crown with Vandyke-brown. The yellow below is deeper and the brown wash on the flanks darker in most cases.” He reports that 6 specimens out of 22 in this plumage show a few white feathers in the orbital ring, usually confined to the lower eyelid, and 3 out of 23 spring males show the same peculiarity, which seems to be purely individual and possibly peculiar to the younger birds.
The adult nuptial plumage is “acquired by wear,” although he thinks there must be only a limited prenuptial molt, for he examined specimens of this species taken eveiy month in the year, but found “only a few young birds shcwing actual moult in February, March and April.” He adds that “the adult nuptial and winter plumages are so extremely similar that wear alone might convert the latter into the former,” although ex en with the large series he examined positive conclusions were not possible.
In the female “the plumages and moults correspond to those of the male. In juvenal plumage the sexes are alike. In first winter plumage the female is much browner, the yellow of the lower surface is wholly replaced by buff, and there is no black about the head. The first nuptial dress is assumed by a limited prenuptial moult (sometimes suppressed) illustrated by a specimen of February 4th. Later plumages differ little, except in yellowness, from the first winter dress and no black is ever assumed about the head.”
Albinistic plumages of the yellowthroat have been reported.
Food: In the case of the yellowthroat, as of other birds which usually inhabit places remote from agricultural areas, no studies based on the stomach contents of a large and representative number of individuals has been made. However, from various field observations and the few stomachs that have been examined we know the yellowthroat is insectivorous in its food-eating habits. In its n~sting haunts it has been observed feeding on beetles, grubs, larvae and adults of moths and butterflies, flies, ants, spiders, plant lice, and such insects as leafhoppers and leaf rollers which are abundant among the grass and low-growing herbage that it frequents.
E. II. Forbush (1907) writes: “I watched a Maryland yellowthroat on the low willow sprouts, and saw him pick off fifty-two gipsy moth larvae before flying away.” Mr. Forbush concluded in his study of the gipsy moth infestation in Massachusetts that the yellowthroat ranked among the efficient enemies of this pest. At another time Mr. Forbush saw one eat 89 aphids during the course of one minute.
S. A. Forbes (1883), in the examination of three stomachs of the yellowthroat, found four-fifths of the food consisted of canker worms and other undetermined caterpillars, 8 percent consisted of Coleoptera (beetles), gnats amounted to 4 percent, and a small hemipteran (Pieama ci’nerea) was found. Others have reported yellowthroats in orchards where their chief food seemed to be cankerworms. A. XV. Butler (1898) gives the summary of food eaten by 11 specimens of the yellowthroat examined by Prof. F. H. King as follows: 22 casebearing caterpillars, 5 other larvae, 6 small dragonflies, 3 moths, 3 dipterous insects, 3 small hymenopterous insects, 3 beetles, 3 spiders, 2 small grasshoppers, 1 leafhopper, 2 hemipterous insects, and 2 insect eggs. J. Henderson (1934) quotes Aughey as having reported 8 locusts in the stomach of a single Maryland yellowthroat. C. W. Townsend (1905) found beetles, flies, and small seeds in the stomach of a Maryland yellowthroat he collected at Ipswich, Mass., on December 6, 1903.
Under ordinary conditions the yellowthroat secures its food in an environment remote from agricultural areas, orchards, and gardens; thus it may be thought to be of little economic importance. However, since many destructive insects breed in areas inhabited by these birds, and from there spread to cultivated areas, the yellowthroat can be considered a useful insectivorous bird in its food-eating habits.
Nelle E. Shaver (1918) who made a nest study of the Maryland yellowthroat at the Iowa Lakeside Laboratory on Lake Okoboji has presented detailed and painstaking observations on the food delivered to the young by the adult birds. Miss Shaver summarized the results of 1,694 observations made over the entire nesting period from the time the young hatched until they left the nest. The food delivered was as follows: Unidentified insects 376, moths 347, various larvae 290, spiders 280, mayfles 116, flies 61, unrecognized material 92, caterpillars 20, damselflies 54, beetles 13, chrysalids 13, butterifies 11, seeds 10, caddisflies 3 ,grasshoppers 6. Miss Shaver states further:
The birds gleaned their food from the ground and the shrubbery close to the ground. The greater amount of the food for the young was such as must have been picked from low bush.~s around the nest. The small moths which were so numerous in the grass, seemed to afford an unfailing source of supply.
The “worms” were the usual miscellaneous assortment, mostly with a greenish color. These were, of course, gleaned from the foliage. The number of spiders taken by these birds was an interesting fact. * * Sometimes the food morsel was large, and the time required by tile young in swallowing made identification possible. At other times the food was small and the feeding process was so rapid that identification was impossible. Much of the small stuff may have consisted of plant lice, etc.
Voice: The northern yellowthroat may be heard in full song soon after the arrival of the males in spring. Although the song is subject to great individualistic and local variations its characteristic rhythm and the loud, clear, and strongly accented syllables make it distinctive and easily identifiable. But while the song of the yellowthroat lends itself readily to syllabification, few interpreters agree as to what the bird seems to say. It utterances have been rendered as: I beseech ~you, I beseech you, I beseech you,~ witchity, wichity, wichity; witch-awee-o, witch-a-wee-o, witch-a-wee-o,~ peachity, peachity, peachity, etc. ~Vitmer Stone (1937) in his study of the Maryland yellowthroat at Cape May, N. J., emphasizes the idividual variation of the song. He states that no two appeared alike, although each carries a similar phrase that is characteristic and gives to all songs an impression of identity. He offers 13 interpretations of songs he recorded and claims that it was very easy to identify individual birds after their songs were memorized.
Aretas A. Saunders has given us his interpretation of the song as follows: “The song of the yellowthroat consists of 3 or 4 repetitions of a phrase of 2 to 6 notes, with 1 note of the phrase strongly accented. The phrases vary greatly in different songs and individual birds. Some phrases are very common, while others are comparatively rare. 3- or 4-note phrases are much commoner than others. In 106 records of the song of this species, only 1 is of 2-note phrases; 7 are of 5 notes and 3 of 6. The remainder are almost equally divided between 3 and 4. In 5 of these records the phrase is sung only twice; in 67 records three times, in 32 four times, and in 2 five times.
“Probably the commonest phrase is one of three notes, the first highest in pitch, and the last lowest; the first note the one usually accented. This is commonly sung with three full phrases and the first note of a fourth, wit’ato-wit’ato-wit’ato-wit. This is sometimes varied by making it a phrase of four notes, each lower in pitch than the preceding one, making the phrase wee’titato. In the Allegany State Park this is the commonest yellowthroat song. Another common song has the second note highest, and accented, witee’to, and this is varied by two notes on the same pitch before the accented note titiway’to. There are many other variations, but they seem to be less common than these. In all these, however, the song is readily recognized, for it is much more definite and distinctive than most warbler songs.
“The pitch of songs varies from D”’ to D’ ” ‘, or one octave. Single songs commonly have a range of one and one half to two and one half tones, a very few only one tone, and a few others up to three and one half tones. Songs vary in the rapidity of the phrases and range from 1% to 224 seconds in length. Usually about two phrases occuy 1 second of time.”
The song of the northern yellowthroat may be heard throughout the nesting season but in the last weeks of July and the first week of August singing is less general and less spirited. I have never heard the song in Maine after the last week of July, but observers in other sections of its range have heard it throughout the month of August and as late as the second week of September, although this late singing is unusual. M. B. Trautman (1940) in his intensive study of the birds of Buckeye Lake, Ohio, writes: “The song period began with the first male arrivals in the spring, reached its height in mid-May, and continued undiminished until late June. There was less singing in early July, and by August it had ceased almost entirely. A few birds continued to sing throughout summer and fall, especially in the early morning. An individual on Lieb’s Island sang during late October and until November 2, 1929, the last day on which it was observed.” Others have reported individual birds remaining throughout the winter, as far north as Toronto, Canada, that were heard singing their characteristic song in spite of snow and severe weather conditions.
Aretas A. Saunders writes that the northern yellowthroat sings until August 1, an average based on 14 seasons in Allegany State Park. The latest date on which the song was heard was August 8, 1929. Frank L. Burns (1937) states that the approximate duration of the yellowthroat’s song is 87 days, extending from May 5 to July 31. Of this time the two nesting cycles were in progress for a period of 77 days. In Arkansas W. J. Baerg (1930) writes that in a 5-year period of study the average singing period extended from April 15 to August 10, or 117 days, about a month longer than the determinations made by Burns in Pennsylvania.
The northern yellowthroat seems to exhibit some ability in imitating the song of other birds. E. M. S. Dale, of London, Ontario, writes to us: “For several days in early May 1933, we heard a chippingsparrow-like song coming from the edge of Spettique’s Pond (a mile or two south of London). We were unable to catch a glimpse of the singer until the fifteenth, when we got a good look at it in the very act, and were much surprised to find that it was a northern yellowthroat. We were wondering if it had been listening to swamp sparrows and had copied them. In 1936 a similar case occurred, when we heard what we took to be a short-billed marsh wren singing, only to find that it was the yellowthroat again. I guess we would have all put it down for a wren without thinking a second time, but one of the party took the trouble to look it up. On May 14, 1937 we heard what was without doubt the same bird singing the same wren song from the same location. Here are two instances of a marsh bird whose song imitated very closely the songs of two other marsh birds, the normal songs of the three species being about as unlike as it is possible to get them.”
H. Mousley (1919) has determined that the “singing tree,” or the place selected by the male for singing, was near the nest; in five nests the distance varied from only 7 to 11 yards. He found this information useful in locating the nests.
H. IV. Wright (1912) found that the awakening song of the Maryland yellowthroat at Jefferson Highland, in the White Mountains of New Hampshire, begins on an average at 3: 51 a.m. but varied from 3:41 to 3:55a.m.
The yellowthroat in its haunts is generally well concealed from view, and since it is readily excited and disturbed by our approach, the first indication to us of his presence is a sharp echek, schick, or chit note which is excitedly uttered as he hops nervously about in the thicket closely scrutinizing our movements to determine whether we are friend or foe. At other times he may be heard to utter a slight chip or tip note.
In addition to the ordinary, or territory, song the yellowthroat has a so-called flight song which is more generally heard late in the season after the birds have begun nesting. The flight song is not so highly developed in the yellowthroat as it is in the true flight singers of the open grass areas, nor is it as spectacular as the performance of two ether warblers, the ovenbird and the yellow-breasted chat. The flight song of the yellowthroat is merely an outburst of ecstasy consisting of short, confused, and sputtering notes, but generally including phrases of the common song. It is uttered as it gracefully flies up from the ground to a height of 15 to 20 feet. The song ends while the bird is at its highest point of the flight. He then silently drops to the place from which it started. The flight song is more often heard in the late afternoon or toward evening than it is during the early part of the day.
E. H. Forbush (1929) presents an account of a flight song of the yellowthroat, which was most unusual for the height at which the bird flew during the performance, as follows:
There is an occasional song-flight that goes far beyond the ordinary. I recall but one high-flyer, and probably a high flight is very unusual. One such is described by Miss Florence M. Pease as follows: “On May 14, 1914, I saw a Maryland yellow-throat fly very high, then spiral down and then fly off toward the church, where It was still a good distance from the ground. I was not able to estimate accurately how many feet the bird flew up, but I noted that when It began to spiral down it was far, far above the church steeple. I had always supposed that the flight-song of the Maryland yellow-throat was given from a height of a few feet.”
Enemies: The yellowthroat is subject to the usual enemies of birds that nest near or on the ground. I remember finding a nest of the yellowthroat in a grassy area near a meandering meadow brook in central Illinois where snakes were common. During a second visit to the nest, when the young were 3 days old, I saw a large water moccasin disappearing into the vegetation as I approached. Two of the young were missing and I presume, judging from the behavior of the adults, they were victims of the unwelcome visitor.
A. L. Rand (1943) cites a report from Lake Okeechobee, Fla., in October 1942, where a 3-pound large-mouthed bass was found to have a yeflowthroat in its stomach. These fish often feed in shallow water among the water-hyacinth where they could easily capture a bird as they do various insects on or near the surface. Mr. Rand mentions reports of other birds captured by black bass and since yellowthroats are frequent visitors to such situations in quest of insects, it may not be a rare incident. Turtles have been known to capture small birds and may also prove to be an enemy of the yellowthroat.
However, the number of yellowthroats that fall victims to natural enemies are insignificant when compared with the appalling losses suffered by this species dur~ng the migraticn, especially when the great migration waves meet with severe storms and foggy weather. D. E. Culver (1916) gives an account of a large number of birds that were killed on May 21 and 22, 1915. by flying into public buildings and the City Hall in Philadelphia. On May 21 there was a heavy mist or fog prior to the storm, but this was later cleared away by falling rain. Many of the birds became exhausted from continuous fluttering about the lights and later succumbed to exposure, but the death of the majority w.s caused by dashing into the structures. The Maryland yellowthroat suffered the greatest mortality, Mr. Culver recovering 130 of this species of which threc -fourths were females. This sex ratio was due to the lateness of the season, as the males are the first to migrate. Culver also reports that during a migratory wave, October 17 and 18, 1915, the yellowthroat was again killed in large numbers, the total being exceeded only by that of the myrtle warbler.
Robert Overing (1938) on September 12, 1937, between 10: 30 p. m. and midnight identified 576 individuals of 24 species which struckthe Washington Monument. There was a slight mist enveloping the top of the shaft and the wind velocity was 8 to 10 miles an hour. Mr. Overing identified 189 Maryland yellowthroats and other subspecies of Ceothlypis tricha8.
‘W. E. Saunders (1930) writes of the great loss of bird life at Long Point lighthouse, Ontario, during certain nights of September 1929. Out of 2,060 birds killed on September 7, 9, and 24: 29, 254 of them were Maryland yellowthroats, this being the most frequent victim of the 55 species reported.
A. M. Frazar (1881) reports a great destruction of birds on April 2, 1881, during a sea trip from Texas to Mobile, Ala. Land birds including a great number of Maryland yellowthroats were seen to perish. Even those that came aboard the boat were washed into the sea again.
The yellowthroat is a frequent victim of parasitism by the cowbird. L. E. Hicks (1934) reports that out of 41 nests of the northern yellowthroat he has found 19, or 41 percent, that were parasitized by the cowbird. Dr. Friedinann (1929) states that at Ithaca, N. Y., the yellowthroat stands seventh in order of the birds most frequently imposed upon by the cowbird. There are many instances on record where the cowbird has been successful in having the yellowthroat accept its eggs and of rearing the young to maturity. However, some circumvent the intrusion by building a second nest over the first containing the egg of the cowbird, a method frequently employed by the yellow warbler. A. W. Butler (1898) writes of a 3-story nest of the yellowthroat as follows: “Mr. E. R. Quick has in his collection a three-story nest of this bird, taken near Brookville, md. Two additional nests were built upon the original structure, burying beneath each the egg of the cowbird (Molothrus ateT). Thus it outwitted the detestable parasite, and in the third nest deposited her complement of eggs. Similar nests have been found elsewhere, showing that this is not an individual peculiarity, but others of its kind had experimented along the same line.”
The northern yellowthroat is host to a number of external parasites of which Harold S. Peters (1936) has identified the louse Ricinus valiens (Kellogg) and the two flies Ornynoica con fluenta Say and Ornitkoinyia anchineuria Speiser.
Fall: There are so many breeding birds on the migration range of the yellowthroat that it is not easy to mark the beginning of the southward migration in the autumn. The bulk of the birds leave their northern breeding grounds in September, but even in these northern sections many birds linger well into October, a few as late as November. Indeed there are a number of records of birds seen throughout the winter months.
M. B. Trautman (1940) writes of the fall migration at Buckeye Lake, Ohio, as follows: “Upon a few occasions the chip note of night migrating birds was recognized as early as late July, and a few apparent transients were seen dropping earthward in the early mornings. Evidence of migration was always apparent by August 10. The peak of migration took place between late August and late September, and then the species was as abundant as in spring. It disappeared between October 5 and November 2.” At Oneida Lake, N. Y., according to D. Stoner (1932) fall migration begins in September and by mid-October practically all of the birds have left the territory.
At the Florida lighthouses, where specimens have been recovered, thus making it certain that individuals of the northern yellowthroat are migrating, the first birds appear about the middle of September. They are reported to reach Cuba during the last two weeks of the month. The earliest arrivals reach Jamaica the first week of October and have been reported in Nicaragua during the last week of October.
Winter: The winter ranges of the nirthern and Maryland yellowthroats overlap to a great extent. The records are confusing in certain cases, and we cannot be sure that the races are properly designated. The northern yellowthroat winters from southern United States to the Bahamas and the West Indies and through eastern Mexico to Costa Rica. The Maryland winters from North Carolina and Louisiana to Florida, the Bahamas and Haiti. An adult male was taken by Todd (1922) as far south as the Santa Marta region, Colombia.
Dickey and Van Rossem (1938) have found the northern yellowthroat a common midwinter visitant in El Salvador. They write as follows:
The northern yellowthroat was not detected in the fall, even in localities where later in the year it was present in numbers. It is safe to say that few, If any, reach El Salvador before about January 1, after which date the species is common and generally distributed In marshland, shrubbery along streams, and even In fern bracken up to 8,000 feet in the Arid Upper Tropical Zone.
The northward migration is chiefly during early April. At Lake Olomega from April 1 to 5, 1926, and at San Salvador until April 17, 1912, yellowthroats were very common, much more so than during the winter. However, some individuals remain very late in spring; indeed, locally, they are sometimes actually common in the middle of May. An instance of this Is the fact that at Lake Chanmico from May 13 to 17, 1912, braclUdact pie was frequently noted In the grass and mimosa scrub about the edge of the lake. A peculiarity of this occurrence was that the birds were usually In pairs. The two males taken were in breeding condition, and the single female had rapidly developing ova.
Dr. Alexander F. Skutch has sent us the following notes concerning the yellowthroat (races not designated) in Central America: “Like so many of the warblers that winter in Central America, the yellowthroats are abundant in the north but rare in the south. In Panamci and Costa Rica it has been very rarely recorded; I have seen it only once during eight years in these countries. In Guatemala, it winters in fair numbers at lower elevations, on both sides of the Republic, upward to at least 3,000 feet above sea level. I saw two at IPanajachel, 5,000 feet above sea level, in late October; but it is possible that at this date they had not yet settled down for the winter. This single bird I met on the Sierra de TeqAn, at 8,500 feet, on March 7, 1933, was obviously only a transient: I saw no other of the kind during the course of the year. In the lower Motagua Valley, I found the yellowthroat an abundant winter resident; and it was not rare on the great coffee plantations of the Pacific slope. It frequents low-lying pastures where the grass is tall, moist thickets, and the brakes of giant cane along the rivers. Always solitary, it shows no tendency to flock.
“The yellowthroat arrives late and apparently has not been recorded before October. In April, when the migratory movements begin, these birds become exceedingly abundant in the Motagua Valley of Guatemala. They linger into May, rarely past the middle of the month; and I have recorded males as late as females. On May 7, 1932, I heard a male, the last of his kind I saw that year, sing repeatedly but rather weakly, among tall, lush grass in the Motagua Valley.”
Dr. Barbour (1923) states the northern yellowthroat is a common winter visitant in Cuba, where it is found about marshes, in cane brakes and reed beds, and in lowland thickets of vines and lianas.
In the Isle of Pines, W. E. C. Todd (1916) states that the Maryland yellowthroat is a common winter resident throughout the northern part of the island where it inhabits the low, wet thickets.
In Haiti and the Dominican republic Wdmore and Swales (1931) state: “The yellow-throat is found in numbers at the proper season in weed-grown fields, and the borders of marshes in the lowlands, and also ranges widely into the higher altitudes where there is suitable corer for it. It lives near the ground concealed in the dense growths that it affects, coming out on open perches for a few seconds and then dodging quickly out of sighs or flushing with tilting flight to fly for a few yards before disappearing again into its coverts. Attention often is directed to it by its harsh call note, a low chimp, as it scolds whenever disturbed.”
So many individuals of yellowthroats have been found wintering well north of the usual winter range of these birds that it has become something more than an accidental occurrence. A few representative records in this connection are of interest. Baillie and Thompson (1928) report that a Maryland yellowthroat was seen December 25, 1927, in a sheltered ravine of Hyde Park, Toronto, Canada. It was a male in good plumage; it was active and uttered its characteristic song. M. B. Trautman (1933) saw a male northern yellowthroat during a severe cold snap during mid-March at Buckeye Lake, Ohio. It was wintering in the cattails which stood beside a 2-foot snow drift at the time it was seen The bird was collected and upon examination was found to be fat and in apparently good condition.
C. W. Townsend (1905) writes: “I found a Maryland yellow-throat on December 6th, 1903, in the sand dunes just back of Ipswich Beach, among some bayberry bushes and goldenrod stalks. There was about an inch of snow on the ground and the thermometer early in the morning was only 150 F. The bird proved to be a young male, quite fat, with its stomach filled with insects, mostly beetles and flies, and a few small seeds. Its plumage was interesting, as it had partially assumed the first nuptial plumage.” Since Dr. Townsend’s winter record there have been numerous winter records of the northern yellowthroat in Massachusetts as well as in other sections of New England. The yellowthroat is a regular winter resident from North Carolina southward.
Range: North America, Central America, and the West Indies.
Breeding range: The yellowthroat breeds north to southeastern Alaska (Chickamin River) ; southern Yukon (Jarvis River at Alaska Highway, Champagne, and Pelly River); northern Alberta (Peace River area, and the Athabaska Delta) ; south-central Saskatchewan (Manito Lake, Emma Lake, and Yorkton); southern Manitoba (Brandon, Aweme, Pembina, Lake St. Martin, Shoal Lake, and Carman); central and northern Ontario (Kenora, Lac Seul, Roseport, Amyot, and Moose Factory); central and southeastern Quebec (Mistassini Post, Lake Albanel, Godbout, Mingan, Natashquan, and Anticosti Island); and southern Newfoundland (Lewis Hills, Grand Lake, Pushthrough, possibly Gooseberry Island, and Exploits River). East to Newfoundland (Exploits River); Connecticut; New York; eastern Pennsylvania; western Maryland (Cranesville) ; Virginia (Emporia, Pungo, and Dismal Swamp) ; North Carolina (Wadesboro and Raleigh) ; South Carolina (Greenwood, Lancaster) ; Georgia (Atlanta, Athens, Newton, and Saint Marys) ; and eastern Florida (Gainesville, Micanopy, Deep Lake, Royal Palm Hammock, and Miami). South to Florida (Miami, Tallahassee, and Pensacola); southeastern Alabama (Abbeville and Dothan) ; southern Mississippi (Gulfport and Biloxi); southern Louisiana (Pilot Town, Houma. Vermillion Bay, and Sunset) ; southern Texas (Brownsville) ; northwestern Chihuahua (probably San Diego); and Colima (Colima and Manzanillo). West to Colima (Manzanillo); Nayarit; Sinaloa; Sonora (Tepopa Bay and Kino Bay) ; Baja California (San Ram6n, Rosario, San Felipe) ; coastal California (Santa Barbara, San Rafael, San Francisco Bay) ; western Oregon (Portland, Salem, and Corvallis) ; western Washington (Sumas, Seattle, Grays Harbor, Tacoma) western British Columbia (Kispiox Valley, Hazelton, Comax, and Chilliwack) ; to southeastern Alaska (Chickamin River).
Winter range: The yellowthroat winters north to northern California (Eureka); southern Arizona (Yuma and Tucson) ; southern Texas (Brownsville and Beaumont) ; southern Louisiana (Chenier au Tigre, Grand Isle, and New Orleans) ; southern Mississippi (Biloxi); and North Carolina (Raleigh and Lake Mattamuskeet). East to North Carolina (Lake Mattamuskeet); Georgia (Atlanta and Savannah) ; throughout Florida; Cuba (Isle of Pines); Jamaica; the Bahamas (Bimini, Andros, Nassau, and Hog Island); Haiti (Gon&ve); Dominican Republic (Fort LiberiA); and Puerto Rico (Guajatico Reservoir). South to Puerto Rico (Guajatico Reservoir); and Panama (Volc~n de Chiriqui). West to Panamti (Volc~n de Chiriquf); Costa Rica (San Jos~); Nicaragua; Honduras; El Salvador; Guatemala; Quintana Roo; Oaxaca (Huajuapan); Guerrero (Coyuca) ; Baja California (Cabo San Lucas, Miraflores); and along the California coast to Eureka.
The range as outlined is for the entire species of which 12 subspecies are recognized. The northern yellowthroat (C. t. brachidactyla) breeds from southeastern Manitoba, central and northeastern Ontario, central and southeastern Quebec, and the southwestern half of Newfoundland south to western North Carolina and west to central and northeastern Oklahoma, Kansas, and central Nebraska; the Maryland yellowthroat (C. t. trichas) breeds from southern Pennsylvania south to northern parts of Georgia and Alabama, and to eastern Texas; the Florida yellowthroat (0. t. ignota) is a permanent resident in southeastern Louisiana, southern Mississippi, and Florida; the Athens yellowthroat (C. t. typhicola) breeds from southeastern Virginia to central Alabama; the western yellowthroat (C. t. occident alis) breeds from central northern and southeastern Oregon, southern Idaho, southwestern Wyoming, central northern Colorado, southwestern Nebraska, and southwestern and central southern Kansas, south to central eastern California, south-central Nevada, central southern Utah, northern and central eastern Arizona, northern and central eastern~New Mexico, and northern Texas; the Pacific yellowthroat (G. t. arizela) breeds along the Pacific coast in southeastern Alaska, to northwestern, central northern, and central California; the salt marsh yellowthroat (G. t. sinuosa) breeds in the salt-water marshes of the San Francisco Bay area of central western California; the Sonora yellowthroat (G. t. chryseola) breeds and is probably resident in southeastern Arizona, southern central and southeastern New Mexico, and western Texas, south to northeastern Sonora and northwestern Chihuahua; the tule yellowthroat (C. t. scirpicola) is a resident race in southern California, southeastern Nevada, southwestern Utah, and westernmost Arizona, south to northern Baja California; the Brownsville yellowthroat (C. t. insperata) is a resident race of the Rio Grande delta region below Brownsville, Texas; the San Bias ye]lowthroat (C. t. modesta) is a resident race along the western coast of Mexico from central western Sonora through Sinaloa and Naysrit to Colima; and the northern plains yellowthroat (C. t. cam picola) breeds in southern Yukon, northeastern British Columbia, northern Alberta, south-central Saskatchewan, and southwestern Manitoba; south to southeastern Alaska, central Oregon, central Idaho, northeastern Colorado, and North Dakota.
Migration: Late dates of spring departure are: Colombia: Lake Macotama, Santa Marta region, April 21; Baud6 Mountains, near Nuqui, June 16. El Salvador: Lake Chanmico, May 17. Costa Rica: Basin of El General, May 2. Honduras: near Tela, April 28. Guatemala: near Quirigu~, May 7. Tabasco: Balanc~n, May 9. Puerto Rico: Desengano, April 18. Dominican Republic: May 8. Jamaica: Spanishtown, May 10. Cuba: Cienfuegos, May 12. Bahamas: May 10. Florida: Lower Florida Keys, May 21. Arizona: Tucson, June 7. California: Pasadena, May 20.
Early dates of spring arrival are: Bahamas: Cay Sal, March 13. Florida: -Sombrero Key Light, March 3. Alabama: Greensboro and Shelby, March11; Birmingham, March14 (average of 10 years, March 17). Georgia: Savannah, March 12. South Carolina: Columbia, March 11. North Carolina: Raleigh, High Rock, and Washington, March 20 (average of 30 years at Raleigh, March 28). Virginia,: Cape Henry, March 7 (average, April 7); Rockbridge County, April 18. West Virginia: Bluefield, April 14; French Creek, April 27 (average of 17 years, May 1). District of Columbia: Washington, April 11 (average of 57 years, April 22). Maryland: Baltimore and Patuxent Wildlife Research Refuge, April 12. Delaware: Kent and Sussex Counties, March 4 (average of 21 years, March 20). Pennsylvania: Carlisle, April 3; Kennett Square, April 15. New Jersey: Camden, April 3; Trenton, April 20. New York: Staten Island, April 10; Poughkeepsie, April 14; Watertown, April 22. Connecticut~: Carrollton, April 25. Massachusetts: Woods Hole, April 17. Vermont: St. Johnsbury, May 1. New Hampshire: East Westmoreland, May 3. Maine: Waterville, April 18; South Harpswell, May 4. Quebec: Montreal, May 4. New Brunswick: Fredericton, April 30. Nova Scotia: Yarmouth, May 9. Newfoundland: St. Andrews, May 27. Louisiana: Bains, March 30. Mississippi: Edwards, March 10. Arkansas: Monticello, March 26. Tennessee: Nashville, April 6 (average of 12 years, April 8); Elizabethton, April 1. Kentucky: Bowling Green, April 8. Missouri: Pemiscot County, April 8. Illinois: Murphysboro, April 15; Chicago region, April 20 (average May 4). Indiana: Carlisle, April 17. Ohio: Oberlin, April 13; Columhus, April 17 (average for central Ohio, April 25). Michigan: Ann Arbor (University), April 17. Ontario: London, April 25; Ottawa, May 4 (average of 9 years, May 16). lowa: Elkader, April 19. Wisconsin: Prairie du Sac, April 10; Madison, April 24. Minnesota: Lanesboro, April 30 (average of 40 years for southern Minnesota, May 9). Texas: White Rock, March 9. Oklahoma: Adair County, April 7. Kansas: Wichita, April 12. Nebraska: North Platte, April 18. South Dakot.a: Yankton, April 30. North Dakota: Devil’s Lake region, May 3. Manitoba: Treesbank, May 13. Saskatchewan: Regina, May 7. New Mexico: San Antonio, March 28. Utah: Wendover, March 15. Arizona: Tucson Valley, February 29. Colorado-Colorado Springs, April 2. Wyoming: Douglas, April 16; Laramie, May 2 (average of 10 years, May 10). Idaho: Moscow, May 1. Montana: Fortine, May 9. Alberta: Banif National Park, May 5. California: San Clemente Island and Colorado River Valley, March 23. Nevada: Millett, April 26. Oregon: Jackson County, March 22. Washington: Yakima County, March 29. British Columbia: Courtenay, Vancouver Island, April 15.
Late fall departure dates are: Alaska: Taku River, September 9. British Columbia: Okanagan Landing, October 10; Comox, Vancouver Island, October 12. Washington: Bellingham, October 1. Oregon: Eugene area, October 18. Nevada: Indian Springs, Charleston Mountains, October 11. California: Coalinga, October 22. Alberta: Glenevis, October 8. Montana: Bozeman, October 8. Idaho: Moscow, October 4. Wyoming: Douglas, October 16; Laramie, October 12 (average of 7 years, September 18). Colorado-Boulder, September 30. Arizona: Tucson, November 11. Utah: Deep Creek, October 5. Saskatchewan: Eastend, September 28. Manitoba: Brandon, October 5; Aweme, September 26 (average, September 17). North Dakota: Fargo, October 18. South Dakota: Yankton, October 15. Nebraska: Hastings, October 8. Kansas: Lake Quivira, Johnson County, September 27. Oklahoma: Oklahoma City, October 16; Copan, November 29. Texas: El Paso, October 26. Minnesota: Hutchinson, October 26 (average of 14 years for southern Minnesota, September 27). Wisconsin: Mazomanie, October 18; Madison, December 21. lowa: Osage, October 26. Ontario-Fort Albany, James Bay region, September 22; Ottawa, September 27; Hamilton, December 19; Toronto, December 25 and 26. Michigan: Erie, November 29; Sault Ste. Marie, December 1. Ohio: Toledo, Nov ember 23; Buckeye Lake, November 2 (average, October 14). Indiana: Bloomlngton, November 4. Illinois: Chicago, October 28 (average of 15 years, October 9). Missouri: St. Louis, October 19. Kentucky: Bowling Green, October 29. Tennessee: Elizabethton, October 27. Mississippi: Oxford, October 10. Newfoundland: Cape Anguille, October 3. Nova Scotia: Wolf yule, October 4. New Brunswick: Saint John, October 15. Quebec: Montreal, October 14; November 29. Maine: Bath, October 21, November 10; Portland, December 8. New Hampshire: Hanover and Sandwich, October 22. Vermont: Rutland, October 23. Massachusetts: Cambridge, November 26; East Orleans, December 10. Rhode Island: Little Compton, November 5. Connecticut: Portland, November 7; West Hartford, November 12. New York: Rochester, October 28; numerous November and December records near the coast. New Jersey: Union County, November 24 (average, October 21). Pennsylvania: Renovo, October 24; Jeffersonville, November 1. Maryland: Baltimore County, October 27. District of Columbia: Washington, November 2 (average of 20 years, October 6). West Virginia: Bluefield, October 21. Virginia: Rockbridge County, October 21. North Carolina: Raleigh, October 24 (average of 8 years, October 13). South Carolina: Spartanburg, October 16. Georgia: Tybee Light, October 21; Demarest, November 30. Alabama: Birmingham, October 22 (average of 10 years, October 19).
Early dates of fall arrival are: California: Cactus Flat, San Bernardino Mountains, August 16. Arizona: Huachuca Mountains, August 25. Illinois: Chicago, August 21 (average, August 29). New York: New York City, August 13. Maryland: Patuxent Wildlife Research Refuge, August 12. Georgia: Tybee Light, September 23. Florida: Sombrero Key, September 12. Cuba: Cienfuegos, September 5. Dominican Republic: Ciudad Trujillo, September 30. Puerto Rico: Monte Grande, October 31. Yucat~n: Chich~n-ItzA, October 8. Honduras: near Tela, October 3. Nicaragua: Escondido River, October 28.
Egg dates: Arizona: 11 records, May 30 to July 22; 7 records, June ito 9.
California: 66 records, April 4 to July 10; 33 records, May 1 to 20, indicating the height of the season.
Florida: 11 records, April 22 to July 20; 6 records, April 26 to May 7.
Massachusetts: 97 records, May 23 to June 27; 55 records, May 30 to June 8.
Nova Scotia: 9 records, June 4 to 26 (Harris).
GEOTHLYPIS TRICHAS IGNOTA Chapman
CONTRIBUTED DY ALFRED OTTO GROSS
The Florida yellowthroat was first described by Frank Chapman (1890) based on an adult male in breeding plumage taken at Tarpon Springs, Fla., May 19, 1887. His description is as follows:
Above olive green with a slight rusty tinge, somewhat lighter on the rump and tall; wings brownish, the feathers edged with the color of the back, the outer web of the first primary whitish, the carpal bend yellow. A broad black facial mask includes laterally the eyes, auriculars, and sides of the throat, reaching on the forehead to near the posterior margin of the eyes, and Is bordered by a band of hoary ash, which has no abrupt posterior termination but, suffusing the crown, changes gradually into the color of the back. Under parts rich yellow, whitish on the centre of the abdomen; flanks rich ochraceous brown, the sides of the breast slightly washed with the same color. Measurements: Wing 2.26; tail, 2.32; tarsus, .84; exposed culmen, .50 inch. * * *
Adult female in breeding plumage. * * * Similar in color to the male, but without the black mask and ashy border, the crown being rusty brownish, paler on the forehead. * * *
Adult male in winter. Similar to adult male in the spring but darker above, the ashy band bordering the black mask restricted to a narrow line; crown rich rusty brown, brighter anteriorly, where also the feathers have more or less ashy and yellowish bases, and fading gradually into the color of the back; abdomen somewhat paler. * * *
Adult female in winter. Similar to adult fall specimens of triehas, but darker above, with the yellow of the breast and underparts washed with brownish.
Immature birds. Immature birds’ of both sexes are not readfly distinguishable from wintering northern specimens, and from the nature of the case there are at this season specimens showing every degree of intergradation, both as regards size and coloration. Generally speaking the resident birds are slightly darker above, with the marking of the under-surface deeper in color and of greater extent.
The Florida yellow-throat is similar to the Maryland yellow-throat, but with a longer tarsus, tail, and bill; yellow of underparts of a deeper shade and greater extent; flanks of a much darker color; the upper parts broxvner; the facial mask wider, with its ashy border (in summer specimens) slightly paler and of greater extent. First primary shorter, equalling the eighth instead of the sixth, as in the Maryland yellow-throat.
The breeding range of the Florida yellowthroat as formerly defined included the region from the Dismal Swamp region of Virginia, the coast of South Carolina, central Alabama, and central Georgia to Florida and along the Gulf coast to Louisiana. Since the Athens yellowthroat (typhicola) has been recognized, the breeding range does not extend farther north on the Atlantic coast than northern Florida (Burleigh, 1937). Tn a later paper Burleigh (19Mb) states the Florida yellowthroat has an extremely limited range on the coast of Mississippi. Specimens were taken every month of the year except July along a narrow southeastern coastal area but it was noted only once, during the summer, on any of the islands off the coast. Breeding birds taken only 22 miles inland north of Gulfport were found to be intermediate in their characters between the Florida and the Athens yellowthroat. The Florida yellowthroat breeds throughout Florida and is practically resident except in the more northern parts of its breeding range. Possibly a few migrate south of Florida to Cuba, since ignota as well as the two northern forms have been found dead at stations in southern Florida during the migration season.
According to Holt and Sutton (1926) it is abundant in all suitable places throughout southern Florida, but particularly numerous at “‘Gator Lake, in the salt-marsh inhabited by the Cape Sable Seaside Sparrows at East Cape, and along New River near Miami. Common also on the keys off East Cape.” Frank M. Chapman (1907) writes: “In Florida this resident form of the Yellow-throat is so commonly found only in scrub palmettos that it is known as the ‘Palmetto Bird.’ I have also found it about the bushy borders of ‘bay-galls’ surrounded by scrub palmetto, while in the Kissimee region it lives in the lower growth (largely young palms) of cabbage palms.” According to A. H. Howell (1932):
The Florida yellow-throat inhabits thickets and brier patches, being especially partial to wet situations, such as the borders of streams, lakes, and sioughs. The birds are common along the canals in the Everglades, and in the floating vegetation on the upper St. Johns River near Lake Washington, and are found in smaller numbers in dry palmetto thickets on the prairies or in the forests. They are rather shy, and on being disturbed take refuge in the depths of the thickets in which they live, and voice their alarm with a characteristic burring chink. In singing they usually come out to the edge of the thicket or fly to a low perch on a bush or tree.
In winter the Florida yellowthroat is common about cultivated lands, in thick scrub and tall switch grass on the prairies and in grassy, marshy situations. Since there is no marked increase in spring, it is another indication that this form is not strongly migratory.
Nesting: The nesting habits of the Florida yellowthroat are similar to those of the northern subspecies. It is interesting that it breeds as late in the season (April 10 to June 9) as do the birds in the middle Atlantic states. The nests are placed in clumps of grass in marshy situations and sometimes in weeds, bushes, and thickets on dry ground. They are loosely woven of dry grasses, stems, and bits of wide blades of swamp grass, and lined with fine grasses; they are seldom placed more than a few inches above the ground.
Eggs: Most of the sets of eggs are four in number but a few with five eggs have been reported. The color and markings of the eggs are similar to those of the Maryland yellowthroat. The measurements of 29 eggs average 17.7 by 13.4 millimeters; the eggs showing the four extremes measure 19.2 by 13.5, 18.6 by 14.0, and 16.1 by 12.4 millimeters.
Food: The yellowthroat is said to be a very beneficial insect-eating bird in Florida, in regions where tomatoes and other vegetable produce is reared. But like the other subspecies of yellowthroats the majority of the birds occupy habitats where the destruction of insects is of less importance to agriculture.
The contents of the stomachs of seven yellowthroats collected in Florida were found by the United States Biological Survey to consist mainly of insects, with a few spiders and small mollusks and a small number of seeds of the sweetgale. Of the insects eaten, Orthoptera (chiefly grasshoppers) and crickets comprise the largest amount, with ilymenoptera (ants, wasps, bees) next in importance. Other forms well represented were beetles, bugs, flies, and caterpillars.
Voice: The song of the yellowthroat as it is heard in Florida is full and strong, and while having the same characteristics, is nevertheless recognizably different from that of the northern yellowthroat we hear in New England. The song has been interpreted as witcker-c/ieree, witclier-cheree, ‘witcher-ekeree, but there is considerable individual variation in the renditions. The song may be heard throughout the spring and summer but in spring it seems to be more spirited and perhaps more elaborate.
The flight song begins as the singer launches forth from his thicket, reaches a climax at a height of 15 or 20 feet, when the head is thrown lztck as when singing at rest, and gradually dies away as the bird sinks down with rapidly vibrating wings. The flight song resembles the following: C/ice, c/ice, chee, c/ice, che-witekery, witchery, witchery, witchery.
Enemies: The Florida yellowthroat like that of its near relatives is subject to parasitism by the cowbird. It is seldom that the young of the yellowthroat survive more than a few days before they are starved or suffocated to death by the much larger and more aggressive cowbird.
Various observers have reported that it frequently falls prey to snakes, turtles, and even fish. This might reasonably be expected of individuals that frequent the swamps and marshlands of semitropical Florida where such enemies are abundant.
Harold S. Peters (1936) has found the tick, Haemapkyealis leporispalustrus Packard a parasite of the Florida yellowthroat. It is of interest that he found no ticks infesting either the Maryland or the northern yellowthroats.
Since the Florida yellowthroat does not migrate to the extent of the northern yellowthroat it does not meet with the extraordinary hazards of a long migration which has been the cause of the death of so many of the northern species.
GEOTHLYPIS TRICHAS TYPHICOLA Burleigh
CONTRIBUTED BY ALFRED OTTO GROSS
The Athens yellowthroat bears a superficial resemblance to the Florida race but can be readily separated from it by its distinctly smaller bill, and less brownish under parts and flanks. The northern yellowthroat can be differentiated from the Athen’s yellowthroat by its larger bill and olive green rather than brownish upper parts.
The Athens yellowthroat is distributed from southeastern Virginia to Georgia and Alabama and in migration to eastern Mexico. Burleigh (1937), in an account of the yellowthroats of Georgia, writes:
The Athens yellow-throat is the most abundant of the yellow-throats occurring In the state, and in fact it is one of the most characteristic birds of Georgia. Except for the limited area occupied by the Maryland yellow-throat it can be found throughout the state, and, while less numerous during the winter months Is to a large extent resident as far north as Athens. In severe winters it is perceptibly scarcer in the northern half of the state, but even with snow on the ground and the temperature well below freezing an occasional bird can be seen in the thickets and stretches of underbrush. All winter records based on actual specimens taken have without exception been found to refer to this race alone.
Specimens of the Athens yellow throat were previously referred to the Florida yellowthroat, a race, as now restricted, that is confined largely to the peninsula of Florida and the coastal regions of southeastern Georgia.
The nesting habits and behavior of the Athens and Florida yellowthroats are similar.
GEOTHLYPIS TRICHAS OCCIDENTALIS Brewster
Contributed by Alfred Otto Gross
The western yellowthroat is a large form of Geothlypis trickas first described by William Brewster in 1883 (Allen and Brewster, 1888). An adult male collected at Truckee River, Key., May 4, 1881, was described as follows: “Upper parts nearly uniform pale yellowisholive, with a tinge of brown on the occiput; throat, jugulum, breast, anterior portion of abdomen, and under tail-coverts rich, pure yellow; sides of body warm ochraceous brown strongly tinged with yellow; middle of abdomen anteriorly creamy white; a black mask on the front and sides of the head bordered behind by a broad band of creamy white, slightly tinged with bluish; much concealed yellow on the feathers of the crown.” In comparing C. tricltas ocoidentalis with C. t. trieltas lie states it “is somewhat larger * * * and its tail is disptoportionately longer. Its upper parts always paler and usually yellower; the yellow of the under parts is decidedly richer and purer, and extends much farther down on the abdomen, frequently tinging nearly all of the body beneath; the flanks are paler and more ochraceous; the white of the head purer and generally broader.”
W. Palmer (1900) in comparing the western with the northern yellowthroat states:
The western bird, occidentalis, is a little larger than bracaidactyla, but grayer in dorsal coloration with a broad white posterior edging of the facial black. The yellow of the throat is more intense and the black of the forehead is relatively narrower. Freshly molted adult birds are but slightly paler dorsally than eastern birds, hut Immature birds are fully as dark and as brown above as in similar aged eastern birds. The females in summer are as a rule less yellowish and paler than eastern birds. A few have decidedly yellow throats but it is far from the rule. The immature females are browner and duller above and beneath with a much browner tinge across the breast than in either trichas or Brochidact pie.
The wing formula and the relative length of the primaries exhibit distinct differences from those of the eastern forms.
The western yellowthroat breeds from Oregon, southern Idaho, and the western portion of the Great Plains (North and South Dakota and Texas) south to northern New Mexico. The distribution of the western yellow-throat in California where there are also the two forms C. t. sinuosa and C. t. seirpicola represented, is complicated. According to Grinnell and Miller (1944): “In breeding season, valleys of northern California from the coast east to the Nevada line; in central California south to northern Sonoma County, thence east of San Francisco Bay through Solano and eastern Contra Costa counties to the Monterey Bay area and the Salinas Valley; extends south into central San Joaquin Valley where intergradation with seirpicola takes place; similarly east of the Sierra Nevada intergradation becomes apparent in Owens Valley, Inyo County.”
In winter the western yellowthroat is found in the Sacramento and San Joaquin Valleys, Calif., from Tehama County southward to southem California, and through Baja California and western Mexico as far south as Cape San Lucas and Tepic, Nayarit. In California migrants appear in all sections of the State, even up the middle elevations in the mountains.
Specimens of the western yellowthroat have been taken as far east as Erie, Mich. (Van Tyne, 1944), and Gulfport, Miss. (Burleigh, 1944).
In Washington, according to correspondence from Samuel F. Rathbun, the western yellowthroat is decidedly localized in its distribution, being restricted to brushy borders of swamps, marshes, lakes, and streams, but very often it is absent from these localities. When seen among the rushes along the edge of some rush-bordered piece of water, climbing actively among the stalks, its actions are reminiscent of those of the tule wrens.
At Fort Klamath, Oreg., J. C. Merrill (1888) writes: “The habits of the Western Yellow-throat in this vicinity, as regards its favorite resorts, are quite unlike what I have elsewhere observed. Though the numerous streams offer it the same rank undergrowth along their swampy edges that it in other places prefers, yet it is rarely seen in such situations. A few are found among the low willows growing in the marsh, but its favorite haunt, and one in which it is very common, is among the tules in company with Marsh Wrens and Yellowheaded Blackbirds.”
In California, Grinnell and Miller (1944) state that its habitat is in the “low thick tangles of plant growth in or about fresh- or brackishwater marshes and sloughs; extremely small areas of flooded ground in river bottoms * * * may suffice. Important is continuous cover for concealment in foraging down to the mud or water surfaces. The sphere of activity is within six feet of the water and principally within three feet.”
In Montana, according to A. A. Saunders (1921) the western yellowthroat is: a very common summer resident in the western half of the state, east to the western part of the prairie region. Apparently rare in the more eastern part of the prairie region, and occuring there only in migration. Breeds throughout the Transition zone, on the prairies, and in the mountain valleys and foothills. Nests in thickets of willow, wild-rose and similar shrubs, in moist places along the streams. The breeding range of the Western Yellowthroat in Montana Is almost exactly coincident with that of the MacGillivray Warbler, hoth being found east of Fergus County and the Musseishell River, but the Yellowthroat is much commoner at low elevations in valleys, and much less common ia the mountain foothills. In many localities, however, the two species are found together.
In Utah where the western yellowthroat is a common resident, except in the southwestern part of the state, W. H. Behle (1944) writes: “[it] occurs in cattail and tule marshes and in willow-cottonwood associatibn bordering valley streams.”
Nesting: In his Birds of California, William Leon Dawson (1923) writes:
Nests of the yellow-throats are the commonplace of all swampy localities: commonplace, yet never without interest, because of their varied architecture and their diverse setting. A nest may be sunk firmly into a tussock of grass barely clear of the ground or water, or it may be lashed firmly to stalks of an investing clump of cattails, or it may be deftly hidden under a canopy of weedtops a hundred feet from water. The nest may be composed chiefly of brittle weathered leaves or grass or sedge, so coherent as to be scarcely removeable, or else it may he settled into a veritable fortress of coiled cattail leaves sturdy and dependable. The lining too, may he of coiled grasses almost as light in color as the speckled white eggs which they support, or it may he of black horsehair, throwing the jewels into prized relief.
Grinnell and Miller (1944) write: “nests are placed low down, often over the water. Plant associations most likely to meet these requirements: growths of cattails, tules and other sedges, especially where tangled and matted; thickets of young willows; blackberry vines, accompanied by nettles and dock.”
A nest collected at Fairbank, Ariz., is described by A. C. Bent (MS.) as follows: “Bulky, loosely built nest made up entirely of coarse strips of sacaton grass and other grasses; no plant down or other soft material. The dimensions were, outer height 3 inches, diameter ~½ inches, inner depth 2 inches and inner diameter 21/4 inches.”
IV. L. Dawson (1923) states the nest is “of course coiled grasses, or, more rarely, leaves of Typha angwstifolia; lined with fine grasses or horse hair.” Others have mentioned that a lining of horsehair is sometimes used, as is also the case of many nests built by the eastern forms of the yellowthroat.
Eggs: The eggs vary from three to five in number but the majority of the nests contain four eggs. They are similar in their markings to those of other forms of yellowthroat, having a ground color of white or creamy white, dotted and spotted or rarely streaked with black, shades of brown, and lavender or vinaceous gray. The markings are usually concentrated about the larger end of the egg.
Food: F. E. L. Beal (1907) in an investigation of the food of the western yellowthroat examined the contents of 114 stomachs of birds taken in California during every month but January. He found the yellowthroat to be practically wholly insectivorous and the insects it eats to be either harmful or of little economic value. It eats no fruit or grain, or, as far as known, any other useful product. Beal states further:
The animal matter amounted to 99.8 percent of the total food. The largest item is Hymenoptera, amounting to 35 percent, of which about half Is ants and the remainder wild bees, wasps, etc. Hemiptera amount to 28 percent, and are made up of leaf-bugs, leaf-hoppers, tree-hoppers, plant lice, scales, and probably some others not identifiable. The black olive scale was found in a few stomachs and plant-lice in one, but the other families were a pretty constant component of the food in every month. Beetles were eaten to the extent of nearly 15 percent, and are mostly harmful specles: The three orders of insects [Hymenoptera, Hemiptera, and Coleoptera] mentioned above form the greatest bulk of the food of the yellowthroat, and are regularly eaten throughout the year.
Caterpillars and moths comprise 5 percent, Diptera 12 percent, spiders 4 percent. Grasshoppers were found in four stomachs.
The vegetable food was incidental and was probably taken accidentally when other food was being secured. It consisted of only a few seeds and vegetable rubbish.
Voice: The song of the western yellowthroat is similar to that of the eastern forms but William Leon Dawson (1923) has presented some interesting and unusual interpretations as follows:
Mounting a weed-stalk, he rubs out, Recs’iwitte, recs’iwitte, nt, or I beseeck you, I beseech you, I beseech. Rhythm is the chief characteristic of this song, and although a given bird appears to be confined to a single type, the variety of feet offered by a swamp is most entertaining. Chit’ooreet, ciut’ooreet chu’; heard on the edge of a northern pond, reminded me of the Kentucky warbler (Oporornis formosus) while another, less ambitious, lisped, 0-Us twi88′-pe, O-ti8 twiss’ ye. Returning to the typical rhythm, one indignant swain near Los Angeles, shouted, Greas’y unities, greo.s’y wit ties, Grit! * * *
But by far the most remarkable song in my experience came from a locality in eastern Washington. We had just been listening to the unwonted notes of a Desert Sparrow * * * some hundreds of miles out of its usual range, and we were not unprepared for shocks, when Hoo hee, chink i woo chu tip fell upon our ear. Again and again came the measured accents, clear, strong and sweet. Not till I had seen the mandibles of a Western Yellow-throat, and that repeatedly, moving in perfect rhythm to music, could I believe so small a bird the author of this song. For fifteen minutes the Warbler brought forth this alien strain, Hee-o chili wo, cha tip, or Hee 00 chitiwcw chu tipew, without once lapsing into ordinary dialect.
Mr. Dawson also describes a harsh accusing note uttered by the western yellowthroat which he describes as “a sort of Polish consonantal explosion, wzschthub,: a sound not unlike that made by a guitar string when struck above the stop.”
Richard Hunt (1919) describes and presents an excellent analysis of. the song of the western yellowthroat he heard on the campus at Berkeley, Calif., as follows:
As I listened from an office window, a single clear and near example of the song reached my ears. It was an utterance in four sections, the first three being four syllabled and exactly alike: pnitisitta, pritisitta, pritisitta, prit, with accent on the pnit. I had never heard a Yellowthroat song of this exact syllabification, hut the chief and important distinguishing character of the song of the species is, after all, its exact repetition of some sort of two- or three or four-syllabled word. Every individual Yellowthroat has quite a stock of different words, and some are likely to he different from any words one would hear another Individual sing. Timbre, to be sure, is also a character of the Yellowthroat song: though It varies among and In individuals as widely as does the word-form. The timbre of this song was hardly typical: it was unusually loose and liquid. The utterance was comparatively slow.
Samuel F. Rathbun writes that in Washington the western yellowthroat sings from the time of its arrival, during the last week of April, until nearly the end of July.
Like its eastern relatives, the western yellowthroat has a characteristic flight song which has been noted by various observers but I have seen no published accounts of the details of the performance.
Enemies: The western yellowthroat is frequently parasitized by the cowbird, and several writers claim that it is one of the most frequent victims in their respective localities. The records range from Colorado to Utah, the latter probably referring to the sagebrush cowbird. In California this yellowthroat has been reported as being parasitized by the dwarf cowbird.
While the yellowthroat resides in a habitat where it would not be expected to be molested, nevertheless, according to various reports, it is often a victim of predatory birds. W. L. Finley (1907) relates an experience in which a Cooper’s hawk attempted to strike the birds he was observing.
Migration: The dates of migration of the western yellowthroat seems to vary greatly in different pads of the ~vest, depending on the altitude, climate, and temperature of the regions traversed. W. W. Cooke (1904) states: “The birds arrive at just about the same time: second week in May: on the plains of north-central Colorado and at Great Falls and Columbia Falls, Mont., the latter place almost 600 miles farther north, but enjoying at this period of the year an equal degree of warmth with the Colorado plains. But almost a month earlier than this, southern British Columbia is reached by the yellowthroats that wintered in the warm valleys of California lying as far north as the plains of north-central Colorado which during the winter season can support no warbler life.”
It is difficult to follow the migration of the western yellowthroat, as it passes through regions where it is resident and where other subspecies are also resident. In Arizona it is a common migrant in April and May (throughout May at Shiprock, N. Mex.) and has been reported at Rinconada May 5, 1904. It has been recorded as late as May 10 at Ortez, Sonora, Mexico. Spring dates in California are: Colorado River Valley and San Clemente Island, March 23; Pasadena, March 25; Berkeley, May 21; and Yosemite Valley, May 25. The western yellowthroat arrives in Oregon during April, the earliest date for Jackson County is March 22 and the earliest date for Lake County is April 9. In Washington it reaches Seattle April 17: 21; Hoquiam, April 27; Ocosta, April 30; Tacoma, April 6: 12; and Yakima County, March 29. Migration in the autumn begins in August and continues through October. There are numerous winter records of the western yellowthroat in California, so that fall as well as spring records mean little in following migration. It has been recorded at San Bernardino Ranch, Sonora, Mexico, August 26 to September 8, 1892; and at San Pedro River, October 7 to 15, 1892.
NORTHERN PLAINS YELLOWTHROAT
GEOTHLYPIS TRICHAS CAMPICOLA Behle and Aldrich
CONTRIBUTED BY JAMES LEE PETERS
The breeding yellowthroat of the northern Rocky Mountains and northern Great Plains region was named by Behle and Aldrich (1947) who characterized the race as follows:
Similar to Geotidypis trickas occidentalis of the Great Basin, but upper parts grayer, less yellowish olive green; yellow of underparts less extensive posteriorly; belly and flanks grayer, averaging more whitish, less huffy. Similar to 0. t. orizela of the humid coast belt west of the Cascade Range, but also grayer on upper parts; white frontal stripe broader; yellow of under parts slightly paler and less extensive; posterior underparts whiter, less huffy. The range assigned to this race by its describers is as follows: “Breeds east of the Cascade Mountains in northern Oregon, Washington, and British Colombia, thence east through northern Idaho, Alberta, Saskatchewan, Montana, northern Wyoming to northern North Dakota. In migration occurs southward in Utah, Colorado, and Arizona. Winter range undetermined.
GEOTHLYPIS TRICHAS SINUOSA Grinnell
CONTRIBUTED By ALFRED OTTO GROSS
The salt-marsh yellowthroat is known also as the San Francisco yellowthroat because of its restricted distribution chiefly in theregion about that city. This form was described by Joseph Grinnell (1901) as follows: “Similar to Geotklypis trickas occidentalie, but dorsally and laterally darker in color, and size much less. Thirteen specimens (males) from the marshes of San Francisco Bay measure: Wing 51 mm. to 54.6 mm. averaging 53 mm.; tail 52.6 to 56.6 mm. averaging 55 mm.”
Grinnell and Miller (1944) give an account of its status, range, and habitat as follows:
Status: Resident; hut to some degree scatters or migrates from breeding range In San Francisco Bay region to appear, fairly commonly, as ~ winter visitant in southern California from late September to mid-March. Common throughout year on breeding grounds.
Geographic range: In breeding season vicinity of San Francisco Bay, Mann County, and Napa sloughs, southern Sonoma County, on the north, east to Carquinez Strait, and south to vicinity of San Jose, Santa Clara County. In winter, constal marshes from San Francisco Bay region south to San Diego; also, twice recorded north to Humbolt Bay. Life-zones, Upper Sonoran and Transition; localities of nesting all below 1,000 feet elevation. * * *
Habitat: In summer, fresh and salt water marshes, but chiefly the former. More commonly found near salt and brackish water in fall and winter. Requires plant cover similar to that frequented by the race Geothly pie trichas occident alis [the western yellow-throat]. * * * Tall grasses, tub patches and willow thickets provide normal plant environment for nesting activity.
Milton S. Ray (1916) found three nests of the salt-marsh yellowthroat in the Lake Merced region of San Francisco County on April 22, 1911. Two of the nests had four eggs each in advanced stages of incubation and one contained three fresh eggs. All three nests were about two feet up in wiregrass and were made of coarse flat weed stems lined with fine light-colored grasses, loosely put together. Mr. Ray states this yellowthroat does not inhabit the salt marshes exclusively but 15 much more abundant along fresh-water lakes and streams and in wet meadow land. However, one nest with 4 eggs was found in a salt marsh north of San Rafael on April 12, 1914. This nest was on high ground not subject to overflow. An excellent account of the nestrng habits of the salt-marsh yellowthroat in the Lake Merced region has been written by G. XV. Schussler (1918), as follows:
The nesting period ranges from middle April until June, fresh eggs having been taken on April 2 and June 15. The yellowthroats, habitually suspicious, become doubly vigilant during the breeding season and I think only twice in all the years I have studied them have I surprised the female in the act of carrying nesting material. It has been my experience that if any unfinished structure not containing eggs is located, the birds promptly abandon it. The nest, a cup-shaped, fairly compact receptacle is usually composed of lengths of dried grass ~vell interwoven with the supporting stems. It is commonly hidden in bunches of wire grass or weeds among willows and placed from six to twenty-four inches above the ground. The bowl-like interior is often lined in rather a loose manner with dried grass or thin fiber. The usual complement is four though a set of three, particularly when laid late in the season, is not rare. The eggs are taperingly oval in shape, white, with a decided pink tinge when fresh, and circularly splotched about the larger end with dots and dashes of black, brown, and deep lavender, varying in size from minute markings on some specimens to a pronounced ring of color on others. Incubation, which is performed by the female, usually occupies about fourteen days.
While incubating, the females show remarkable shyness in slipping off the nest and keeping well ahead of the observer, with short undulating flight. Occasionally as evening approaches they are apt to flush from directly beneath one’s feet, particularly should he beat quietly up toward them against the wind. When startled from her nest the female disappears and maintains silence for some moments hut If the intruder remains in the vicinity, or removes the nest or eggs, her sharp chack of alarm will rapidly summon the male and the pair will flit nervously about in the underbrush, often fearlessly approaching within a few yards of the observer.
The young when hatched are naked, hut gradually become sparsely covered with light down. Feeding, which is participated in by both parents, takes place at short intervals during the greater part of the day, until the young are ready to leave the nest. So far as I have been able to observe, the parent birds appear to entice the ambitious nestlings into the tule and willow thickets away from the open flats where they may have been hatched. This is probably In order to afford them the shelter of the branches and, by removing them some little distance from the ground, to protect them against small predatory mammals.
[AUTHOR’S NOTE: The measurements of 28 eggs average 17.1 by 13.2 millimeters; the eggs showing the four extremes measure 18.5 by 13.5, 18.2 by 13.8, 15.9 by 12.9, and 16.3 by 12.4 millimeters.]
Voice: G. NV. Schussler (1918) states that in the winter the saltmarsh yellowthroats are in the seclusion of the high tules standing in deep water. At this season the birds flit out of sight in advance of one’s approach, uttering their solitary chack of protest and suspicion. With the approach of spring they leave the tules to make incursions into the shorter grasses and among the willows. At this period Mr. Schussler has heard them utter a short grating call resembling k-r-r-r-r-r in addition to their familiar chack. He writes of the song as follows:
It is usually not until some warm, sunny morning in late February that the clear ringing umeech-ity wreech-ity, wreech-ity, wreech-ity of the male is heard. The song varies considerably with the season and Individual, those in early spring often sounding sadly out of tune, and some are even rendered In a condensed form of two syllables; but the power of it rises rapidly as the year advances until by the end of March its nuptial gladness pours forth In full-throated volume. Sometimes as evening approaches, one of the little black-faced birds will leap into the air with fluttering wings and expanded tail and as it slowly tumbles down into the grass again, ivill execute an exquisite series of melodious runs and trills not unlike the vocal accomplishments of the chat.
In September the summer songs of the males have ceased and a great diminution in their numbers is noticeable. By November, 8ifluosri has again largely retired to the tule jungle and with his added winter air of distrust is once more the shy flitting figure of the December marshlands.
GEOTHLYPIS TRICHAS CHRYSEOLA Van Rossem
CONTRIBUTED BY ALFRED OTTO GROSS
The golden yellowthroat was described from a breeding adult male, taken June 12, 1929 at Saric, north-central Sonora, Mexico, by A. J. Van Rossem (1930), who says of its subspeciflc characters: “Compared with Geothlypis tricha8 ac ii’ cola, both sexes are brighter and more yellowish above, the yellow of the underparts is brighter and more extensive (the flanks of the males are only slightly, or not at all, tinged with grayish), and the post-frontal white band in the males is even wider and is noticeably suffused with yellow.” Its range, he says, is “north-central Sonora, northeast to the San Pedro River in Cochise County, Arizona; east to northwestern Chihuahua and south, in spring at least, to Tecoripa, east-central Sonora.”
Three of the four localities from which the Sonora yellowthroat is known indicate an upland habitat, and its range, when finally worked out, will probably be found to center in the northern part of the Mexican plateau.
Van Rossem (1945) ,speaking of Mexico, writes: “Evidently a fairly common resident in suitable localities along fresh water streams from the vicinity of Rancho La Arizona (and very probably from the Altar River valley) eastward across the northern part of the State nearly or quite to the Chihuahua boundary. The southernmost breeding station known at the present time is Pilares in the Bavispe River valley. * * * One specimen taken at Tecoripa, March 3, 1929, indicates a seasonal movement by part, at least, of the population.”
Monson and Phillips (1941) state that okry8eola is common at Feldon, Ariz., and that birds taken at Tucson and Bisbee are of this race. Burleigh and Lowery (1940) collected a male 10 miles east of Guadalupe Peak, Tex., at an elevation of 4,500 feet in an arroyo in the open desert on April 29, 1939. Sutton and Burleigh (1939) collected a male several miles north of Victoria, northeastern Mexico on February 25, 1938.
GEOTHLYPIS TRICHAS SCIRPICOLA Grinnell
CONTRIBUTED BY ALFRED OTTO GROSS
The tule yellowthroat was described by Grinnell (1901) as “similar to Geot/dypis trickas ocoide’ntalis, but brighter colored and larger throughout with especially longer tail. Twenty-five males from the Pacific slope of Los Angeles County measure: Wing, 55 mm. to 60.3 mm. averaging 57 mm.; tail, 56 mm. to 64 mm. averaging 60 mm. Scirpicoks is the brightest and deepest colored of all [the western yellowthroats], the yellow of the under parts being more extended posteriorly and having a hint of an orange tint, while the upper parts are brighter brown or green according to age and wear.” A. J. Van Rossem (1930), in comparing the tule with the western yellowthroat, states that it has a brighter coloration and a slightly larger bill. “In sctrpwola the dorsal plumage is greener (less grayish) ; the yellow of the underparts extends farther over the abdomen and is, in a series definitely brighter; the flanks are more brownish (less grayish) and the post-frontal band of white in the males is wider.”
The range of the tule yellowthroat “extends along the Pacific slope from about 30~ in Lower California north to Santa Barbara, California, the southern San Joaquin Valley and Walker Basin on the south fork of the Kern River. The Colorado River drainage colony which is (apparently) isolated from that on the Pacific extends from the mouth of the Colorado River north along that stream, and its tributary the Virgin River, to Washington, Washington County, Utah, west through the Imperial Valley to Mecca, Riverside County, and east up the Gila and Santa Cruz rivers at least to Tucson, Arizona.” In California, according to Grinnell and Miller (19#), the altitudes of occurrence are chiefly below 1,500 feet, but birds may range up to 4,200 feet, as at Julian, San Diego County.
The measurements of 40 eggs average 17.3 by 13.3 millimeters; the eggs showing the four extremes measure 18.9 by 12.5, 18.0 by 14.0, and 16.0 by 12.5 millimeters.
The ecology and nesting habits of the tule and western yellowthroats are similar.
GEOTHLYPIS TRICHAS ARIZELA Oberholser
Some fifty years after it was originally described, the Pacific race was officially admitted to the A. 0. U. Check-List as a recognizable form.
The original describer, Dr. Harry C. Oberholser (1899) gives a detailed description of the type, an adult spring male from Fort Steilacoom, Wash., and writes: “From occidentalis the present race may be readily distinguished by its much narrower white frontal band, and also by its appreciably smaller size; though the former character is of course not available for determination of females and young. It differs from triclzas as does occidentalis, but in dimensions not to so marked a degree. Intermediates between trio/toe and occidentalis such as occur on the Great Plains, come sometimes rather close to arise/a.”
He gives for this form the following distribution: “Pacific coast region from southern British Columbia to northern Lower California; east to the Cascade Mountains and the west slope of the Sierra Nevada; south in winter to Cape St. Lucas and Tepic.”
GEOTHLYPIS TRICHAS INSPERATA Van Tyne
CONTRIBUTED BY ALFRED OTTO GROSS
The Brownsville yellowthroat was described by Josselyn Van Tyne (1933) from an adult male secured in the Rio Grande Delta below Brownsville, Tex., on June 11, 1930:
Subspeciflc characters: Similar to Geothippis tricha8 trichas (Linnaeus) but bill larger, forehead more whitish, and general coloration paler. Compared with Geothlypis trichas occidentalis Brewster it is smaller (wing of male 55: 56 mm. instead of 55: 60 mm.) but has a larger bill. The belly and flanks are more whitish, but the forehead is less extensively white. Compared with Geotlilypis tricha8 brachid~act~fla (Swainson) it is paler and has a shorter wing hut an even larger hill. The ninth primary of in8~erata is shorter than the fourth, instead of longer as in brachidactyla. Two juveniles of the new form, taken June 2 and 4, are much paler and have larger bills than any of a series of brachidactyla with which I have compared them.
Geothllipia trichas insperata has the ninth primary shorter than the fourth, as in Geothlypic trick as ignota Chapman, but is much paler and has a very much larger bilL The larger bill alone is sufficient to separate insperata from the Pacific coast forms.
The Brownsville yellowthroat is known only from the type locality. It leaves the region during the winter but its winter home is not at present known, nor is anything known of its nesting habits.
SAN BLAS YELLOWTHROAT
GEOTHLYPIS TRICHAS MODESTA Nelson
CONTRIBUTED BY ALFRED OTTO GROSS
The San Blas yellowthroat was described by E. W. Nelson in 1900. The description of a male taken at San Blas, Tepic, Mexico, June 12, 1897, is as follows: “Smaller than typical G[eotldypis] triehas from the eastern United States, with the green of back darker, more brownish olive and brownish flanks; black frontlet and white border to same nearly as in Geothlypk trickas oxidentalis. * * * The young as well as the adults are distinguishable by their dark color.”
A. J. Van Rossem (1930) states: “In typical form m~odcsta is a dark colored race. It is much like Geothlypis t~ichas sinuosa of the San Francisco Bay region, but is slightly grayer (less olive) and has a longer tail and decidedly larger bill.” Were it not for the larger bill it would be difficult to distinguish these two races, although their ranges are separated by a gap of over a thousand miles.
The San Bias yellowthroat is resident in a narrow strip of Tropical Zone salt-water associations of western Mexico, from southern Sinaloa northward to Tepopa Bay, and is accidental in Baja California (Magdalena Bay and San Josd Island). Its typical habitat is the mangrove: salicornia association. Nothing is known concerning its habits and nesting.
BELDING’S PENINSULAR YELLOWTHROAT
GEOTHLYPIS BELDINGI BELDINGI Ridgway
This large handsome yellowthroat was discovered in southern Baja California in 1882 by that famous naturalist Lyman Belding, and was named for him by Ridgway (1882). It is considerably larger and much more richly colored than the yellowthroats of the C. trichas group. Belding (1883) found it “common in the few suitable localities around San Josd, Mirafiores, and cafions of the Miraflores and Santiago Peaks.”
Walter E. Bryant (1890b) found it on the west coast “at lower Purisima calion, and as far north as San Ignacio.” lIe says that “the birds kept mainly within the bulirushes and bushes of the creek,” at Comondii on the east coast.
William Brewster (1902) writes: “Mr. Frazar saw his first Belding’s Yellowthroat on April 21 at Triunfo, in a small, deep arroyo where the stream had been dammed for irrigating purposes, making a little pool of water around which grew a quantity of canes and rank grasses, the whole covering an area of about forty yards square. Here were found three pairs, the females of which were apparently incubating, although no nests were discovered. The species was next met with at San Josd del Cabo, where it proved to be one of the most abundant birds. It was also very common about the lagoon at Santiago, frequenting rushes, often where the water was three or four feet deep.”
Nesting: Bryant (1890a) was the first to find and positively identify the nest of Belding’s yellowthroat. lIe found, or had shown to him, five nests near Comondd in 1889. A nest found on March 25 is thus described:
“The nest was loosely woven in a clump of ‘cat-tails’ (Typha) one metre above running water. It is composed outwardly entirely of dry leaves of the ‘cat-tail,’ and thinly lined with fine fiber and a few horsehairs. It measures externally (as nearly as can be determined from its rough shape) not less than 150 mm. in height by about 115 mm. in diameter. The receptacle is about 55 mm. in depth, with a diameter at the top of 50 mm. The general appearance is almost identical with some song sparrows’ nests.” Another nest, found on March 27, was in a similar situation but was oniy half as high. And a third was found on March 28, “in a heavy growth of ‘cat-tails’ near the outer edge of the clump, and placed one and one-half metres high. This nest, like the others, is composed of ‘cat-tail’ leaves, but is lined almost exclusively with black horsehairs, so few being used that they do not even hide the structural material.” It should be noted that the birds breeding near Comondii are somewhat intermediate between the two races, but, as we have no nesting information from the Cape region, it seems best to include these quotations here.
Eggs: Two or three eggs seem to make up the set for Belding’s yellowthroat; 3 seems to be the commonest number. The 12 eggs in the Thayer collection are ovate and slightly glossy. The ground color is white or creamy white, which is rather sparingly speckled, spotted or blotched with “light vinaceous-drab,” “light mouse gray,” “pale brownish drab,” or “Quaker drab,” with fewer spots of “Hay’s brown,” “Dresden brown,” or black. The markings are generally concentrated at the large end, often leaving the small end immaculate. The wreath, which may be made up of fine, dense specklings or spots, often has over-writings of black which circle the egg. The measurements of 32 eggs of the species, some of which may be intermediate between the two races, average 19.5 by 15.0 millimeters; the eggs showing the four extremes measure 21.0 by 16.0, 18.0 by 14.5, and 20.1 by 14.0 millimeters (Harris).
Plumages: Brewster’s fine series probably illustrates all the regular plumages of this yellowthroat. He (1902) describes the juvenal plumage from a specimen taken on September 5, just before the postjuvenal molt, as follows: “Above dull brownish drab, the wings faintly, the tail distinctly, tinged with olive; greater and middle wing coverts edged and tipped with rusty, forming obscure wing bands; below pale brownish buff, deepest on the sides, abdomen, and upper portion of the breast, unmixed with yellow save on the chin, where there are a few bright yellow feathers, evidently those of the first winter plumage; bend of wing slightly yellowish; under surface of wing ashy white; lores with a faint yellowish tinge.”
This and other specimens indicate that the postjuvenal molt of the body plumage and the wing coverts occurs in late August and September. The male in first winter plumage differs from the adult “only in having the feathers of the black mask slightly tipped with grayish or yellowish, especially on the forehead; the yellow border of the mask more restricted and mixed with brownish; the breast and under tail coverts tinged with brownish saffron; the flanks and sides rich purplish cinnamon.” The female in first winter plumage differs from the adult female in autumn “only in having the upper parts tinged with reddish brown, the throat and breast with brownish saffron, the flanks and sides, as well as the anal region, with cinnamon.”
The series indicates that the spring plumage is acquired mainly, if not wholly, by wear in both young and old birds; and there is probably a complete postnuptial molt in late summer. He describes the adult male in fall as “differing from the spring male in having the yellow of the crown paler and tinged with grayish white; the upper parts of a deeper, browner olive, tinged slightly on the occiput and nape with purplish brown; the yellow of the under parts richer with more decided brownish on the sides and flanks; the base of the lower mandible flesh colored; the remainder of the bill dark horn colored instead of black. The black mask is wholly unmixed with any lighter color.” The adult female in autumn differs “from the spring female only in being slightly grayer above.”
Voice: Bryant (1890) writes: “I frequently heard them singing, sometimes in the top of a low tree. Their notes are rather loud and quite clear, an interval of a few seconds occurring between each song. The three songs which I heard sung by the same individual March 31, were noted on the spot. In different places of the song occurred a low, short buzz, represented by stars in the following. The first song occupied about five seconds.
1. Sweet, sweet * * * ear * * * sweet, sweet ear * * *
&iweet, sweet ear.
2. Sweet, sweet ear * * * sweet, sweet ear.
3. Sweet, sweet ear * * * sweet, sweet ear * * According to Brewster(1902), Frazar told him that “the song re sembles that of the Maryland Yellow-throat, but is so much heavier and fuller that it can be easily recognized.” Brewster says further that the bird occasionally mounts into the air and sings on the wing.
Range: Resident in the southern half of Baja California.
Breeding range: The peninsular yellowthroat is resident in Baja California from San Ignacio south to San J05~ del Cabo. Two subspecies are recognized; Belding’s peninsular yellowthroat (G. b. beldingi) is found only in the extreme southern part of the peninsula (Todos Santos, Triunfo, Santiago, Miraflores, and San Jos6 del Cabo); Goldman’s peninsular yellowthroat (0. 6. goidmani) occupies a range in central Baja California (San Ignacio, Santa Igneda, San Joaquin, Purissima, and Comond6).
Egg dates: Baja California: 9 records, March 25 to May 17; 4 records, May 2 to 9.
Mexico: G records, April 9 to June 1; 3 records, May 4 to 18, indicating the height of the season (Harris).
GOLDMAN’S PENINSULAR YELLOWTHROAT
GEOTHLYPIS BELDINGI GOLDMANI Oberholser
Dr. Harry C. Oberholser (1917) described the more northern race of beldingi, Goldman’s peninsular yellowthroat, from the central portion of Baja California, as: similar to GeotiLlypis l~eldingi beldingi, but male with the upper surface much duller, more brownish or grayish (less yellowish) throughout; crown behind the black mask largely or wholly grayish or whitish instead of yellow; yellow of under parts somewhat lighter and confined to throat and breast; lower abdomen white or whitish, Instead of usually deep yellow, as in Geothlypis beldingi; sides and flanks paler and more grayish. Female similar to the female of Geothlypis betlingi, but upper parts and sides of head paler, more grayish (less yellowish) yellow of lo~ver parts paler and less extensive, confined to throat and upper breast, the abdomen being dull whitish, slightly or not at all washed with yellow; sides and flanks paler, more grayish.
He gives its distribution as “central Lower California, from San Jgnacio to Comond4.” But he remarks: “Birds from San Ignacio, which represents the northern limit of its range, are, as would be expected, most extreme in their characters. Two males and two females from Comondii, some distance south of San Ignacio, are intermediate between Geotidypis beldingi goidmani and Geotidypis beldingi beldingi, the females being more like the latter than are the males, which are but slightly different from Geotidypis beldingi goldinani. As a whole the Comondti birds are certainly referable to the northern race.”
From the more northern portion of its breeding range, Griffing Bancroft (1~3O) reports that Goidmans yellowthroat is: resident in Santa Agueda, San Ignaclo, and San Joaquim, the only localities where there is tule. These birds do not appear to care for willow associations. They are fairly common, especially in San Ignacio, where they nest in the heart of the heaviest tule patches. Their nests are strips of dead tule leaves, well woven and tied around several living stalks. The linings show individual variations but are usually of palm fibre. The nests are decidedly larger than those of more northerly birds. * * *
The eggs of gohimoni are a dull white, heavily spotted about the larger end, but otherwise almost immaculate. The decorative scheme is complicated. There are blotches, up to a millimeter in diameter, and a few hair lines which are jet black. A majority of the spots, many three millimeters long, are so weakly pigmented that they are gray and even have a suggestion of a lavender cast. Mixed throughout are specks of either color.
He gives the measurements of 13 eggs as averaging 18.7 by 14.5 millimeters. The measurements of 8 other eggs, apparently of this race, average 19.0 by 14.5 millimeters; the eggs showing the four extremes measure 19.7 by 14.5, 19.3 by 14.8, and 17.8 by 14.0 millimeters (Harris).