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Common
Yellowthroat
Geothlypis trichas [Northern
and Maryland Yellowthroats]
Contributed by Alfred Otto Gross
[Published in 1953:
Smithsonian Institution United States National Museum Bulletin
203: 542-565]
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 brooksides 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. He 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.--It 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
yellowthroat (ignota) whereas the northern (brachidactyla)
follows at later dates. The earliest records for North Carolina
have been reported as the Maryland yellowthroat (trichas).
The matter is 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 brachidactyla, according to E. 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 Yellowthroats. . .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 nest 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 skunk cabbage 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 he 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 ground 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 E. 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 3 1/4 inches, outside depth 3 1/2 inches, inside diameter
of the cup 1 3/4 inches, and its depth 1 1/2 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, but on
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 measure19.4 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 away 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 had 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" by 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 proceeded 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 was 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 olive green.
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 crissum, pale straw-yellow on the abdomen,
the flanks washed with olive-brown, and a very faint buffy
pectoral band." Dr. Dwight notes that "the malar 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 forehead 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
NewYork 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
Mars-brown and the basal black gradually diminishes more
posteriorly as the extent of brown on each feather increases.
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 every month in the
year, but found "only a few young birds showing 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
even 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 nesting 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. H. 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 (Piesma cinerea) was found. Others
have reported yellowthroats in orchards where their chief food
seemed to be cankerworms. A. W. Butler (1898) gives the summary of
food eaten by 11 specimens of the yellowthroat examined by Prof.
F. H. King as follows: 22 case-bearing 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, mayflies 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 bushes 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 the 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. Its utterances have been rendered as: I
beseech you, I beseech you, I beseech you; witchity,
wichity, wichity; witch-a-wee-o, witch-a-wee-o,
witch-a-wee-o; peachity, peachity, peachity, etc.
Witmer 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 2/5 to 2 2/5 seconds in length. Usually
about two phrases occupy 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 chipping sparrow-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. W. 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 3:55 a.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 tchch,
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 other 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 yellowthroat 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 during the migration, 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 was caused by
dashing into the structures. The Maryland yellowthroat suffered
the greatest mortality, Mr. Culver recovering 130 of this species
of which three-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
struck the 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 Geothlypis trichas.
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. Friedmann (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, Ind. Two additional nests were
built upon the original structure, burying beneath each the egg of
the cowbird (Molothrus ater). 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 pallens (Kellogg) and the two flies Ornynoica
confluenta Say and Ornithomyia 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
northern 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 8, 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, brachidactyla 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 Panama 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 Panajachel, 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 Tecpan, 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 Wetmore 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 cover 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 sight 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 15o 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.
Common Yellowthroat*
Geothlypis trichas
[Northern and Maryland Yellowthroats]
Contributed by Alfred Otto
Gross
*Original Source: Bent,
Arthur Cleveland. 1953. Smithsonian Institution United
States National Museum Bulletin 203: 542-565. United States
Government Printing Office
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