warbler is widely distributed throughout that region. "It is found in
the lowlands to some extent as a summer resident, but by far the greater
number of the birds will be found summering in the more mountainous and
unsettled parts of the region. In some parts it is abundant. During the
migrations I have noted it following the deciduous growth and nearby
conifers along water courses, but when settled in its summer home, it is
almost entirely restricted to the high conifers, a habit that seems to
be followed even during rainy and stormy days. I am of the opinion that
it must nest at a considerable height, for on several occasions I have
seen the birds carrying material into trees at a height of over one
hundred feet."
Taylor and Shaw (1927) write: "On entering the great forest of the
Pacific Northwest, with its solitude, the deep-shaded grandeur of its
brown-barked pillars and its stillness, one can almost imagine himself
in a different world. Incessantly repeated, apparently from the very
crowns of the trees, comes the song of the Townsend warbler, denizen of
upper foliage strata. Found in early summer from Alaska south to the
State of Washington, the Townsend warbler finds on Mount Rainier
approximately the southern limit of its breeding range." Similar haunts
seem to have been chosen wherever the species has been found breeding.
_Spring._--The spring migration, apparently directly northward from
Mexico, seems to be quite prolonged. Dr. Alexander F. Skutch tells me
that the last of the winter visitors do not leave Guatemala until about
the first of May. Professor Cooke (1904) says that "an early migrating
Townsend warbler was seen on April 9 in the Huachuca Mountains of
Arizona. Migrants from Mexico begin to enter southern California April
14 to 20. * * * First arrivals have been reported from Loveland, Colo.,
May 11, 1889." And "the average date of the first seen during five years
at Columbia Falls, Mont., is May 7." Mrs. Amelia S. Allen writes to me
from Berkeley, Calif., that Townsend's warbler is an abundant fall and
spring migrant in California, where it is also a common winter visitant.
"In the spring they begin to increase about the middle of March, when
singing flocks go through the live oak trees, feeding on the small oak
worms. They become less conspicuous after the middle of April, but if
there are rains in the first half of May to delay migrations, occasional
flocks are seen. My latest date is May 17, 1915."
Rathbun, in his Washington notes, writes: "In the spring of 1916, in the
Lake Crescent region, a great majority of the individuals came in two
distinct waves. The first occurred on April 28 and this lasted for two
days, on the second of which the birds were less numerous. After an
interval of a day on which we failed to see any of these warblers, there
followed a second wave, on May 1, much larger than the one preceding. It
consisted of hundreds of these warblers, together with individuals of
other species, the main body of which followed the belt of deciduous
trees along the shore of the lake. This fact we verified by ascending
the adjacent mountain side to a considerable elevation during the
movement, where we found but few birds. Descending to the lake level to
note the migration, we found the birds close to the ground, the trees
being of small size. As most of the Townsend's warblers were males in
high plumage, the sight was most attractive. All were in constant song
and flitting about with rapid movements. In their company were many
chestnut-backed chickadees, a few Sitka kinglets, many Hammond's
flycatchers, and now and then an Audubon's warbler and a red-breasted
nuthatch. This movement began about half past eight in the morning and
lasted until ten o'clock, when the number of birds began to diminish
rapidly, and during the remainder of the day was inconsequential."
On April 25, 1917, he saw a similar flight at the same place. "The day
was rather warm and somewhat overcast, and the wave continued
intermittently throughout the greater part of the day, the song of
Townsend's warbler being much in evidence most of the time. In this
movement the birds passed by in small detached companies at intervals,
but the aggregate number was large."
_Nesting._--Not too much is known about the nesting habits of Townsend's
warbler, but enough is known to indicate that nests reported in willows
during the last century were evidently wrongly identified. The species
is now known to nest only in firs, though possibly it may sometimes be
found to select other conifers as nesting sites. Nests and eggs are
still very scarce in collections.
The first authentic nests were found by J. H. Bowles (1908) near Lake
Chelan, Wash., on June 20, 1908. The two nests, each containing four
newly hatched young--
were both placed about twelve feet up in small firs, one some five feet
out on a limb, the other close against the main trunk. Both were saddled
upon the limb, and not placed in a fork nor in a crotch.
The construction of both nests was identical, and entirely different
from any of the descriptions that I have read. They were firmly built,
rather bulky, and decidedly shallow for the nest of a warbler. The
material used appeared to be mostly cedar bark, with a few slender fir
twigs interwoven. Externally they were patched with a silvery flax-like
plant fiber, while the lining seemed to be entirely of the stems of moss
flowers. To an eastern collector it resembled an unusually bulky and
considerably flattened nest of the Black-throated Green Warbler, lacking
any sign of feathers, however, in its construction.
A nest with five eggs is in the Thayer collection in Cambridge, taken by
C. deB. Green on Graham Island, British Columbia, June 24, 1912. It is
described as placed "on top of the big limb of spruce tree," and is
large, compact, and well-built, being made largely of fine plant fibers,
mixed with strips of grasses, mosses, lichens, fine strips of inner
bark, plant down, and a few spider cocoons--all firmly woven together
and neatly and smoothly lined with long, fine, white hairs and one
feather. It measures externally 2-1/4 inches in height and 3 by 3-1/2 in
diameter; the cup is 1-1/2 inches deep and about 2 inches in diameter.
A set in my collection now in the U.S. National Museum was taken by F.
R. Decker in Chelan County, Wash., on June 23, 1923; the nest was about
15 feet up and 8 feet out on a limb of a fir tree and contained five
fresh eggs. Both birds remained close while the nest was being taken.
Two nests in the Doe Museum, at Gainesville, Fla., were taken by J. H.
Bowles in Washington, 9 and 10 feet up in small, slender firs, June 2
and 4.
_Eggs._--Either 3, 4, or 5 eggs are the numbers in the few recorded
sets. The 5 eggs in the Thayer collection are ovate and have only a
slight gloss. The white ground color is speckled and spotted with tones
of "bay," "auburn," "chestnut brown," "Mars brown," or "russet," with
undertones of "pale brownish drab," or "vinaceous drab." Some of the
eggs have markings of two or three shades of the darker browns, such as
"bay," or "auburn," while others have tones of a single lighter brown,
such as "russet," interspersed with the drab spots. There is not a well
defined wreath on any of these eggs, although the spots are denser at
the large end. The measurements of 40 eggs average 17.4 by 12.9
millimeters; the eggs showing the four extremes measure =19.0= by 12.7,
17.3 by =13.6=, =15.2= by 12.7, and 17.4 by =12.3= millimeters (Harris).
_Plumages._--Maj. Allan Brooks (1934) gives the following good
description of the juvenal plumage of Townsend's warbler: "Upper surface
brownish olive, greener on dorsum and grayer on crown; lores and
auriculars dusky brown, a broad supercilium and malar stripe whitish,
faintly tinged with yellow; chin and throat dusky olive gray passing
into white on the ventral region and crissum, the flanks and breast
streaked with dusky; wings with two white bars formed by the tips of the
greater and lesser coverts, tertials edged with ash gray, the black
central shafts of the white bars seen in the second (first winter)
plumage are barely indicated; tail as in second plumage."
Evidently the juvenal plumage is worn for only a very short time, for in
the bird thus described, collected on July 7, "a few yellow feathers of
the second plumage are appearing." Apparently, the postjuvenal molt is
completed in July and August, and involves the contour plumage and the
wing coverts only.
The young male in first winter plumage is similar to the old male at
that season, but with less black on the head and throat, cheeks more
olive, black streaks on back and sides obsolete, and yellow of the
throat paler. The young female differs from the adult female in a
similar way. There is evidently a partial prenuptial molt in late winter
or early spring, but I have not been able to trace it. Apparently the
black throat is acquired by the young male at this molt, and perhaps
enough of the head and body plumage to make the young bird appear nearly
adult, though the worn and faded juvenal wings and tail will distinguish
it.
Adults have a complete postnuptial molt in July and August. Ridgway
(1902) describes the fall and winter male plumage as "similar to the
spring and summer plumage, but all the black areas much broken or
obscured; that of the pileum and hindneck by broad olive-green margins
to the feathers, the black forming mesial or central streaks, that of
the auricular patch overlaid by olive-green tips to the feathers, and
that of the throat replaced by nearly uniform lemon yellow, with black
appearing as spots or blotches on sides of chest; black streaks on back,
etc., more or less concealed." The adult female fall plumage is "similar
to the spring and summer plumage, but upper parts slightly browner
olive-green, with the streaks obsolete, or nearly so; sides and flanks
tinged with brownish."
Although considerable wearing away of the concealing tips of the
feathers occurs during the winter, thus brightening the nuptial plumage,
there is evidently at least a partial prenuptial molt, especially about
the head and throat, at which the clear black throat of the male is
assumed and perhaps more of the body plumage renewed.
Stanley G. Jewett (1944) describes four specimens of adult males that
are clearly hybrids between this species and the hermit warbler.
_Food._--Professor Beal (1907) examined the contents of 31 stomachs of
Townsend's warblers taken in California from October through January, of
which he says: "The animal food consists of insects and a few spiders,
and amounts to over 95 percent of the food during the time specified. Of
this, bugs make up 42 percent, mostly stink-bugs (Pentatomidae) and a
few leaf-hoppers and scales." Several stomachs were entirely filled with
stink-bugs.
Hymenoptera, consisting of both wasps and ants, are eaten to the extent
of 25 percent of the food. Most of them are winged species. Perhaps the
most striking point in the food of this bird is the great number of
weevils or snout-beetles represented. They amount to over 20 percent of
the food, while all other beetles form less than 1 percent. The greater
number of these insects were of the species _Diodyrhynchus byturoides_,
a weevil which destroys the staminate blossoms of coniferous trees. Five
stomachs contained, respectively, 68, 65, 53, 50, and 35 of these
beetles, or 271 in all. * * * Representatives also of another family of
snout-beetles very destructive to timber were present in a few stomachs.
These were the engravers (Scolytidae), which lay their eggs beneath the
bark of trees, where they hatch, and the larvae bore in every direction.
Caterpillars and a few miscellaneous insects and some spiders make up
the remainder of the animal food.
The less than 5 percent of vegetable food "consists of a few seeds and
leaf galls."
Gordon W. Gullion tells me that in Eugene, Oreg., from early January
until the first of April 1948, Townsend's warblers were observed at a
feeding station almost daily, eating cheese, marshmallows, and peanut
butter.
_Behavior._--A marked characteristic of Townsend's warblers is their
fondness for the tree tops, especially on their breeding grounds and to
some extent at other seasons. In the coniferous forests which they
frequent in summer, they confine their activities almost entirely to the
tops of the tallest fir trees, where they travel rapidly, stopping only
long enough to glean their food and then hastening onward, returning,
perhaps, over the same trees in their active restless foraging.
Later in the summer and as migration time draws near, they are
frequently seen at lower levels, among deciduous trees and in second
growth woods, often in association with kinglets, chickadees, other
warblers, and juncos.
_Voice._--Mrs. Allen (MS.) renders the song as a "_weazy weazy weazy
weazy tweea_, rising in spirals, and the call-note a soft _chip_, not so
metallic as the lutescent's, and less emphatic than the Audubon's."
According to Rathbun (MS.), "its song is heard during May and June quite
persistently under all climatic conditions." Dr. Merrill (1898) says
that the song, as he heard it in Idaho, "usually consists of five notes,
_deé deé deé--d[=e] d[=e]_, all, especially the first three, uttered in
the peculiar harsh drawl of _D. virens_. Later in the season this song
changes somewhat." This second song was heard in low second growth. Mr.
Rathbun also refers in his notes to a different song, heard in some
young second growth; the bird was "singing softly as if to itself, this
being a much more finished performance than the ordinary song, although
identical in construction, the distinction being an elaboration of the
song in full in softer tones." Ralph Hoffmann (1927) found the song of
Townsend's warbler difficult to distinguish from that of the
black-throated gray warbler. "The Townsend Warbler's song has less of
the drawling inflection in the opening notes than the Black-throated
Gray's and often ends with a prolonged _ee-zee_. A song noted by the
writer in the Olympics in western Washington was transcribed as a hoarse
_swee swee swee zee_."
_Field marks._--The adult male Townsend's warbler is distinctively
marked, having the crown, cheeks, and throat black, with bright yellow
spaces between these areas, and an olive-green back and bright yellow
breast, both streaked with black; it has two prominent white wing bars
and considerable white on the outer tail feathers. The female has a
similar pattern, but the colors are much duller and she has no black
throat. Young and adults in the fall are much like the adult female in
spring, but are more or less clouded with brownish. There is no other
western warbler that is much like it.
_Fall._--Theed Pearse tells me that he has seen Townsend's warblers on
migration through Vancouver Island, British Columbia, as early as August
13 and as late as October 9, but gives no winter records. Rathburn gives
me two winter records for the vicinity of Seattle, Wash.; D. E. Brown
took two males on January 9, 1921, and saw "a number of others"; and a
week later he collected a female. These were doubtless, winter casuals,
as the summer residents and transients pass through Oregon in October or
earlier.
Mrs. Allen writes to me from Berkeley, Calif.: "The Townsend Warbler is
an abundant fall and spring migrant and a common winter visitant. In
Berkeley the average date of arrival in the fall is September 28 (18
records), the earliest August 27, 1931. They are most abundant during
October, after which they are reduced to winter numbers."
Henshaw (1875) writes:
At Mount Graham, Ariz., in September, this warbler was found in
considerable numbers, though the few taken were procured with no little
difficulty, for they almost invariably were seen in the tops of the
tallest trees, where a glimpse might now and then be had of them as they
dashed out after flying insects, or flew from tree to tree in their
always onward migratory course. The tracts of pine woods they shunned
entirely, but affected the firs and spruces, and their flights from
point to point were regulated and made longer and shorter by the
presence or absence of these trees. Their movements were exceedingly
rapid; a moment spent in passing in and out the interlacing branches, a
few hurried sweeps at their extremities, and they were off to the next
adjoining tree to repeat the process again and again till lost sight of
in the dense woods.
_Winter._--A few straggling Townsend's warblers spend the winter
occasionally as far north as Oregon and Washington; the species is
fairly common from central California southward; but the main body of
the species retires to Mexico and Central America. Mrs. Allen tells me
that they are quite abundant in the redwood trees of California in
winter; and in midwinter, she has "many records of their coming under
the eaves of the house, where they seem to be taking spiders."
Dr. Skutch has contributed the following account: "Townsend's warblers
winter in vast numbers in the highlands of Guatemala. From their arrival
in September until shortly before the departure of the last in May, I
considered these the most abundant of all birds, whether resident or
migratory, between 7,000 and 10,000 feet above sea-level on the Sierra
de Tecpán in west-central Guatemala. Here they were almost equally
numerous in the forest of pine, oak, alder and arbutus and in the nearly
pure stands of lofty cypress trees (_Cupressus benthamii_) on the
mountain-top. But they are widespread over the Guatemalan altos, from
5,000 to 10,000 feet above sea-level, and even pass the winter at
considerably lower altitudes, where pine woods locally replace the
broad-leafed forest prevalent in these less elevated regions. Thus on
the Finca Mocá, a huge coffee plantation lying on the southern side of
the Volcán Atitlán, a local stand of pine reaches to about 3,000 feet
above sea-level. Among these pines I found Townsend's warblers wintering
down to at least 3,400 feet, in company with such birds as hermit
warblers and Coues' flycatchers--all of them highland species which I
failed to find at so low an altitude in the neighboring dicotyledonous
woods more typical of the region.
"By the time the Townsend's warblers began to arrive from the North, the
great majority of the resident birds of the Sierra de Tecpán had
finished breeding for the year, and those of sociable habits had begun
to flock. The pretty Hartlaub's warblers (_Vermivora superciliosa_)
formed the nuclei of the mixed companies of small birds which roamed
through the rain-drenched woods at the beginning of September. The newly
arrived Townsend's warblers at once joined these flocks, falling in with
the resident birds as though they had never been absent in far northern
lands. Soon they outnumbered all other birds in these motley parties.
They were monotonously abundant; and despite their beauty, I was more
than once exasperated, when I had striven until my neck ached to obtain
an adequate glimpse of some small, elusive bird flitting through the
high treetops, to find at last that it was just one more Townsend's
warbler. There was always another of the same kind much lower among the
branches, which I might have admired with less flexure of the neck! At
5,000 feet and below, the plainly attired Tennessee warbler replaces the
elegant Townsend's warbler as the most abundant member of the mixed
flocks.
"By the middle of April, the Townsend's warblers on the Sierra de Tecpán
began to sing--a dreamy, lazy sort of song, which reminded me much of
that of the black-throated green warbler. Through the remainder of the
month, I repeatedly heard this simple song, sounding always as though it
came from far away. Soon the ranks of the Townsend's warblers began to
thin; and after May 2 I saw them no more. Males were present as late as
April 28; but the last that I saw, on May 2, was a female. The
withdrawal of the countless black-and-yellow warblers, together with
that of the other migratory species that flocked with them, left a void
among the treetops, which was not filled until their return just 4
months later.
"Early dates of fall arrival in Guatemala are: Guatemala City (Anthony),
September 7; Sierra de Tecpán, September 2, 1933; Huehuetenango,
September 11, 1934. Late dates of spring departure from Guatemala are:
Guatemala City (Anthony), May 1; Sierra de Tecpán, May 2, 1933."
Dickey and van Rossem (1938) say that "Townsend's warbler is a decidedly
uncommon species in El Salvador, which probably marks about the southern
limit of the winter range. The winter distribution, locally, is
practically confined to the oaks and pines of the interior mountains
where conditions most closely parallel those prevailing in the breeding
range."
DISTRIBUTION
_Range._--Western North America.
_Breeding range._--Townsend's warbler breeds =north= to southern Alaska
(Seldovia, Port Nell Juan, and Cordova); and southern Yukon (Lapie River
and Sheldon Lake). =East= to eastern Yukon (Sheldon Lake and Lake
Marsh); central to southeastern British Columbia (Atlin, Bear Lake,
Tacla Lake, and Revelstoke); southwestern Alberta (Banff National Park);
and western Montana (Fortine, Columbia Falls, Great Falls, and Red
Lodge). =South= to central southern Montana (Red Lodge); northwestern
Wyoming (Mammoth Hot Springs); northern Idaho (Falcon and Moscow); and
southern Washington (Blue Mountains, Preston, and Mount Adams). =West=
to western Washington (Mount Adams, Mount Rainier, Seattle, and
Bellingham); western British Columbia (Comox, Vancouver Island, and the
Queen Charlotte Islands); and southern Alaska (Craig, Baranof Island,
Glacier, Cordova, and Seldovia).
_Winter range._--The Townsend's warbler is found in winter in two widely
separated areas. It is found in varying numbers in the coastal region of
California from Mount St. Helena, Sonoma County, south to San Diego, and
on the Santa Barbara Islands. A specimen collected at Patagonia,
southeastern Arizona on December 3, may have been wintering. It also
winters in the mountains of western Mexico and Central America from
Guerrero (Tlalixtaquilla); and the Federal District (Tlalpan); through
Oaxaca (La Parada and Totontepec); Guatemala (Huehuetenango, Tecpán,
Dueñas, and Guatemala); El Salvador (Los Esesmiles and Mount
Cacaguatique); to central northern Nicaragua (Matagalpa).
_Migration._--Late dates of spring departure are: El Salvador--San José
del Sacore, March 16. Guatemala--Tecpán, May 2. Nayarit--Tres Marías
Islands, May 11. Sonora--Oposura, May 31. Texas--Boot Spring, Chisos
Mountains, May 16. New Mexico--Rinconada, May 6. Arizona--Rock Canyon,
Santa Catalina Mountains, May 25. California--Buena Vista, May 10.
Early dates of spring arrival are: Hidalgo--Jacala, March 28.
New Mexico--Apache, April 23. Arizona--Tombstone, April 3.
Colorado--Loveland, May 11. Wyoming--Cheyenne, May 11. Montana--Columbia
Falls, May 4. Idaho--Coeur d'Alene, April 29. Oregon--Sutherlin, April
21. Washington--Bellingham, April 25. British Columbia--Courtenay, March
28; Atlin, May 18. Alaska--Craig, April 27.
Late dates of fall departure are: Alaska--Ketchikan, September 5.
British Columbia--Atlin, September 1; Okanagan Landing, September 15.
Washington--Tacoma, October 3. Alberta--Jasper Park, September 8.
Idaho--Priest River, September 10. Montana--Missoula, August 31.
Wyoming--Laramie, October 18. Colorado--Fort Morgan, October 12.
Utah--Bryce Canyon, October 7. Arizona--Mineral Creek, Pinal County,
November 2. New Mexico--near Corona, October 18. Oklahoma--Kenton,
September 27. Texas--Glenn Springs, Brewster County, October 19.
Chihuahua--Durazno, November 7.
Early dates of fall arrival are: Oregon--Fremont National Forest, August
20. California--August 26. Utah--Beaver Creek Canyon, August 10.
Arizona--San Francisco Mountain, August 21. Wyoming--Laramie, August 11.
Colorado--Estes Park, August 14. New Mexico--Apache, August 2.
Texas--Pulliam Canyon, Chisos Mountains, August 26. Chihuahua--Saltillo,
August 28. Guatemala--Tecpán, September 2. El Salvador--Divisadero,
September 27.