mention hackberry leaves, hairs, pine needles, horsehair, and cedar bark
in their Tennessee nests. They say that from 6 to 10 days were required
for nest construction, and that from 3 to 5 days more elapsed before the
first eggs were laid. Their four nests were all in bird-boxes; one was
in an orchard over plowed ground, one over a lotus pond in a wooded
ravine, and two were over lily pools near buildings.
Dr. Walkinshaw (1938) publishes a map showing the location of 21 nesting
boxes along the winding banks of the Battle Creek River, in Calhoun
County, Mich., and writes: "Of the 28 nests found during 1937, 19 were
in bird-houses over running water, 6 were in stubs over water (2 of
which were over running water), and the other 3 were in natural holes
back from the river bank. Of 44 nests found from 1930 through 1937,
excluding the 21 in bird-houses, six were over running water in old
woodpecker holes, one in a bridge-support in a slight depression, and
nine in natural holes over standing water. Seven were in old woodpecker
holes from two to a hundred and sixty feet back from the river-bank."
Many and varied are the odd nesting sites occupied by prothonotary
warblers. Dr. Thomas S. Roberts (1936) writes:
The vagaries of this bird in choosing artificial nesting-places are
shown by the positions of the following nests. On the La Crosse railroad
bridge: in a cigar-box nailed on the engine-house on top of the draw; on
one of the piers; in a metal ventilator-cap four inches in diameter,
that had fallen and lodged just at the point where the draw banged
against the pier, and close under the tracks; in a shallow cavity in a
piece of slab-wood nailed to a trestle-support close under the road-bed
of the railroad; these all far out in the middle of the Mississippi
River. Still others are: in a Bluebird box on a low post by a
switching-house and busy railroad platform; in a cleft in a pile in the
river; in a tin cup in a barn, to reach which the birds entered through
a broken pane of glass; in a pasteboard box on a shelf in a little
summer-house; in an upright glass fruit jar in a house-boat; and other
similar situations. In most cases the birds had to carry the
nesting-material long distances, especially to the places on the bridge.
John W. Moyer (1933) relates an interesting story that was told to him
by people living in a farm house along the Kankakee River. A pair of
these warblers built their nests and raised their broods for three
consecutive seasons in the pocket of an old hunting-coat, hung in a
garage; each year the man cleaned out the nest and used the coat in the
fall, and the next spring the birds used it again. M. G. Vaiden tells me
of a similar case.
Nests have been found in buildings, on beams and other supports. Louis
W. Campbell (1930) reports two on shelves in sheds, one in a small paper
sack partly filled with staples and another in a coffee can similarly
filled. Nests in cans in various situations have been found a number of
times, and others have been reported in a tin pail hung under a porch,
in a mail box, in a box on a moving ferry boat, in a Chinese lantern on
a pavilion, and in an old hornets' nest.
Dr. Walkinshaw writes to me: "At Reelfoot Lake, Tenn., during July,
1940, I found 8 nests of the prothonotary warbler, all built a few feet
above the water in small natural holes in cypress knees. Evidently these
are regular late-summer nesting sites." The knees were farther under
water earlier in the season. Most of his 76 Michigan nests were over
water, or less than 100 feet from it; but 10 were 300 or more feet away
from it and 2 were over 400 feet away. M. G. Vaiden tells me of a pair
that nested in the tool box of a log-loading machine that was in daily
operation, hauling logs.
_Eggs._--From 3 to 8 eggs have been found in nests of the prothonotary
warbler, from 4 to 6 seem to be the commonest numbers, 7 is a fairly
common number, and at least 3 sets of 8 have been reported; in the
J. P. Norris series of 70 sets are 34 sets of 6, 15 sets of 7, and
2 sets of 8.
The eggs vary in shape from ovate to short ovate, and they are more or
less glossy. The eggs are undoubtedly the most striking of the warblers'
eggs, with their rich creamy, or rose-tinted cream, ground color, boldly
and liberally spotted and blotched with "burnt umber," "bay," "chestnut
brown," and "auburn," intermingled with spots and undertones of "light
Payne's gray," "Rood's lavender," "violet-gray," and "purplish gray."
There is quite a variation in the amount of markings, which are
generally more or less evenly scattered over the entire egg; some are
sparingly spotted and blotched, while others are so profusely marked as
almost to obscure the ground color (Harris).
J. P. Norris (1890b), in his description of his 70 sets, describes 2
eggs in each of 2 sets as "unmarked, save for four or five indistinct
specks of cinnamon." These were in sets of 6 eggs each. Pure white,
unmarked eggs were once taken by R. M. Barnes (1889). Dr. Walkinshaw
(1938) gives the measurements of 78 eggs as averaging 18.47 by 14.55
millimeters; the eggs showing the four extremes measured =20= by 15, 19
by =16=, and =17= by =13= millimeters.
_Incubation._--The eggs are laid, usually one each day, very early in
the morning; Dr. Walkinshaw (1941) says between 5:00 and 7:00 a. m. in
Michigan; Meyer and Nevius (1943), in Tennessee, saw the female enter
the nest to lay as early as 5:00 a. m. on May 2, and as early as 4:44 on
May 23, remaining in the nest from 28 to 36 minutes on different
occasions. The period of incubation is recorded as 12, 13-1/2, and 14
days by different observers; about 13 seems to be the average, according
to Dr. Walkinshaw (MS.), probably depending on conditions and the method
of reckoning. Incubation seems to be performed entirely by the female,
but the male feeds her to some extent while she is on the nest.
Incubation starts the day before the last egg is laid.
_Young._--Meyer and Nevius (1943) write:
The adults shared feeding duties, and both removed fecal sacks. During
the first three days the female steadily brooded the young. One female,
observed from 4:55 to 8:10 a. m., when the young were one day old, spent
a total of 70 minutes off and 155 minutes on the nest. Trips from the
nest lasted an average of 8.6 minutes, while periods on the nest
averaged 19.4 minutes. * * * At one nest when the young were eight days
old, activities were noted during the eight and one-half hours from 8:30
a. m. to 5:30 p. m. The young were fed an average of 16 times an hour.
* * * The adults were seen carrying spiders and insects, small green
caterpillars frequently being used. Mr. H. P. Ijams saw a male offer a
10-day old nestling a may-fly. An incubator-hatched bird accepted
egg-yolk, ants, ant larvae, crickets, earthworms, and spiders.
They say of the development of the young: "The young on the day of
hatching had orange-red skin. The mouth lining was red. Down was
distributed over the frontal and occipital areas of the capital tract,
spinal tract, femoral, altar, and humeral tracts. Feather sheaths of
the alar tracts penetrated the skin the first day after hatching. On the
second day after hatching the eye-slits began to open. Feather sheaths
of the humeral, femoral, and crural tracts emerged on the third day;
those on the dorsal and ventral tracts emerged on the fourth day, and
those of the capital and caudal tracts on the fifth day. On the fifth
day the sheaths began breaking." During the next five days the young
developed rapidly and became more and more active, and on the tenth day
began to leave the nest.
Young observed by Dr. Walkinshaw (1914) at Reelfoot Lake "averaged 11
days of age when leaving the nest in 1939, while 21 young in Michigan
during 1939 and 1940 remained in the nest for a period of 10-3/4 days."
Of the comparative nesting success in the two localities, he says:
In Michigan from 1930 through 1940, 121 nests of the Prothonotary
Warbler were observed. Only 28, or 23.14 per cent, were successful. Out
of 413 eggs, 159 (38.47 per cent) hatched and 100 young were fledged
(.87 per total nest; 3.78 per successful nest). The fledgling success
was 25.66 per cent of eggs laid. More failures in Michigan resulted in
more nestings by individual birds.
In Tennessee during 1939, 30 nests were observed until terminated or
successful; 19 were successful (63.33 per cent) while out of 139 eggs,
78 hatched and all the young lived to leave the nest or 56.11 per cent
fledging success of eggs laid; 2.6 young were fledged per total nest;
4.1 per successful nest.
He also notes that in Michigan the species is typically single-brooded
if the first nesting is successful, but that in Tennessee it is
typically double-brooded.
_Plumages._--According to Dr. Dwight (1900) the natal down, located as
indicated above, is brownish mouse-gray. Ridgway (1902) gives rather the
best description of the juvenal plumage as follows: "Pileum, hindneck,
back, and scapulars dull olive-greenish; wing-coverts, tertials, rump,
and upper tail-coverts slate-gray, tinged with olive, the middle and
greater wing-coverts narrowly tipped with light olive-greenish,
producing two very indistinct bands; secondaries, primaries, and
rectrices as in adults; sides of head pale yellowish olive; chin,
throat, and chest dull light grayish olive, darkest on chest rest of
under parts dull white, passing on sides and flanks into olive-grayish."
In very young birds, according to Dr. Dwight, there is a variable amount
of brownish wash on the back, which fades out to gray. And Dr. Chapman
(1907) says that the white on the inner webs of the tail feathers is
more restricted than in adults and more or less mottled with blackish.
This first plumage is followed in June and July by a partial postjuvenal
molt involving all the contour plumage and the wing coverts but not the
rest of the wings or the tail. The young bird now becomes a golden swamp
warbler, the young being nearly like the adults, the females being
considerably duller in color than the males and having less white in the
tail.
The crown and hind neck in both sexes, both old and young, are washed
with dusky or olive in the fall. Spring plumages are produced by very
slight wear without molt. There is one complete, annual molt in late
summer.
_Food._--Very little seems to have been recorded on the food of the
prothonotary warbler. It is evidently highly insectivorous, obtaining
most of its food from the trunks and branches of trees and shrubs and
from fallen logs. Brewster (1878) says: "This Warbler usually seeks its
food low down among thickets, moss-grown logs, or floating débris, and
always about water. Sometimes it ascends tree-trunks for a little way
like the Black-and-White Creeper, winding about with the same peculiar
motion."
Dr. Roberts (1936) lists "ants, and other insects and their larvae," as
its food. Some of the food of the young is mentioned above, most of
which is doubtless included in the food of the adults. Spiders, beetles,
may-flies, and other insects should be included, as well as many
caterpillars and the larvae of water insects. Audubon (1841) says: "It
often perches upon the rank grasses and water plants, in quest of minute
molluscous animals which creep upon them, and which, together with small
land snails, I have found in its stomach."
_Behavior._--Brewster (1878a) observes:
When seen among the upper branches, where it often goes to plume its
feathers and sing in the warm sunshine, it almost invariably sits nearly
motionless. Its flight is much like that of the Water-Thrush (either
species), and is remarkably swift, firm, and decided. When crossing a
broad stream it is slightly undulating, though always direct. * * *
In general activity and restlessness few birds equal the species under
consideration. Not a nook or corner of his domain but is repeatedly
visited through the day. Now he sings a few times from the top of some
tall willow that leans out over the stream, sitting motionless among the
yellowish foliage, fully aware, perhaps, of the protection afforded by
its harmonizing tints. The next moment he descends to the cool shades
beneath, where dark, coffee-colored water, the overflow of the pond or
river, stretches back among the trees. Here he loves to hop about on
floating drift-wood, wet by the lapping of pulsating wavelets; now
following up some long, inclining, half-submerged log, peeping into
every crevice and occasionally dragging forth from its concealment a
spider or small beetle, turning alternately his bright yellow breast and
olive back towards the light; now jetting his beautiful tail or
quivering his wings tremulously, he darts off into some thicket in
response to a call from his mate; or, flying to a neighboring
tree-trunk, clings for a moment against the mossy bole to pipe his
little strain or look up the exact whereabouts of some suspected insect
prize.
_Voice._--The same gifted writer and careful observer (Brewster, 1878)
gives the following good account of the distinctive song of this
warbler:
The usual song of the Prothonotary Warbler sounds at a distance like the
call of the Solitary Sandpiper, with a syllable or two added,--a simple
_peet, tweet, tweet, tweet_, given on the same key throughout. Often
when the notes came from the farther shore of a river or pond we were
completely deceived. On more than one occasion, when a good opportunity
for comparison was offered by the actual presence of both birds at the
same time, we found that at the distance of several hundred yards their
notes were absolutely undistinguishable; nearer at hand, however, the
resemblance is lost, and a ringing, penetrating quality becomes apparent
in the Warbler's song. It now sounds like _peet, tsweet, tsweet,
tsweet_, or sometimes _tweet, tr-sweet, tr-sweet, tr-sweet_. When the
bird sings within a few yards the sound is almost startling in its
intensity, and the listener feels inclined to stop his ears. The male is
a fitful singer, and is quite as apt to be heard in the hot noontide or
on cloudy days, when other birds are silent, as during the cool morning
and evening hours. The ordinary note of alarm or distress is a sharp
one, so nearly like that of the Large-billed Water Thrush (_Siurus
motacilla_) that the slight difference can only be detected by a
critical ear. When the sexes meet a soft _tchip_ of recognition common
to nearly all the Warblers is used. In addition to the song above
described the male has a different and far sweeter one, which is
reserved for select occasions,--an outpouring of the bird's most tender
feelings, intended for the ears of his mate alone, like the rare evening
warble of the Oven-Bird (_Siurus auricapillus_). It is apparently
uttered only while on the wing.
Although so low and feeble as to be inaudible many rods away, it is very
sweet, resembling somewhat the song of the Canary, given in an
undertone, with trills or "water-notes" interspersed. The flight during
its delivery is very different from that at all other times. The bird
progresses slowly, with a trembling, fluttering motion, its head raised
and tail expanded. This song was heard most frequently after incubation
had begun.
Dr. Roberts (1936) refers to this flight song, as delivered "after the
manner of the Maryland Yellow-throat, * * * consisting first of the
usual rapid monotone of five or six notes and ending with a pleasing,
varied warble, full and strong in some of its notes and far sweeter than
the usual utterance."
Dr. Walkinshaw (1938) says of the usual song: "Uttered at the rate of
five or six times per minute, the song lasts slightly over one second.
It is given all day long from the time of arrival until the young have
left the nest and has been heard as late as the 16th of August (1931).
The frequency is much greater during the early nesting season and during
the earlier hours. During midday on warmer days the number of times per
hour seems much less. Later, from four until near sundown, it again
increases. During late nesting, when the young are about to leave the
nest, the rate again decreases, but it is heard several days after the
young leave the nest." Aretas A. Saunders tells me that the songs are
pitched at C´´´´ or B´´´, and the call note, _tseek,_ at A´´´.
_Field marks._--The golden swamp warbler could hardly be mistaken for
anything else. The rich, brilliant yellow of the head and breast,
sometimes almost orange on the head, only slightly paler in the female,
the absence of wing bars, and the large amount of white in the tail will
distinguish it.
_Enemies._--Dr. Walkinshaw (1941) says that the house wren is a serious
competitor with the prothonotary warbler in Michigan, contending with it
for nesting sites in the bird-boxes.
The cowbird is a persistent enemy of this warbler in spite of its
hole-nesting habits; perhaps if the warbler nested in deeper holes it
might find some relief from this pest. Among 70 sets of eggs of this
warbler in the J. P. Norris collection, 18 contain cowbirds' eggs. Dr.
Friedmann (1929) found no less than 36 records of such parasitism in the
literature, and says: "As many as four eggs of the Cowbird have been
found in a single nest together with four of the Warbler's. There are
several cases on record of doubled-storied nests of this bird, with a
Cowbird's egg buried in the lower story. Such cases are, however, not
common, and usually the Warbler seems to make no attempt to get rid of
the strange eggs." E. M. S. Dale wrote to me of a nest, found near
Toronto in 1933, that contained seven eggs of the cowbird and none at
all of the warbler!
Snakes sometimes destroy the eggs or young.
_Fall._--Dr. Walkinshaw (1938) says that "the majority of the
Prothonotaries leave our rivers [Michigan] by the second or third of
July. One may canoe some years a good many miles during the latter part
of July or the early part of August without finding a single
Prothonotary, whereas in other years many groups can be found. The
majority evidently are early migrants. Very few remain until late August
or early September, the latest date being September 9, 1934, at Battle
Creek."
The 1931 A. O. U. Check-List states that this warbler apparently crosses
the Gulf of Mexico in migration "and is not found in Mexico north of
Campeche," but probably some migration is along the coast of Texas and
Mexico, as suggested by George G. Williams (1945).
Dr. Chapman (1907) says: "The route of the Prothonotary Warbler in its
fall migration is interesting; the breeding birds of the Middle Atlantic
States apparently pass southwest to northwestern Florida and then take a
seven-hundred-mile flight directly across the Gulf of Mexico to southern
Yucatan, instead of crossing to Cuba and thence to Yucatan."
Alexander F. Skutch writes to me: "Unrecorded from Guatemala, the
prothonotary warbler is a rare bird of passage and very rare winter
resident in the more southerly portions of Central America. When
Carriker published his list of Costa Rican birds in 1910, he had a few
records from the highlands--apparently of migrating birds--and from the
Pacific lowlands, but none from Caribbean lowlands. But on March 4,
1934, I found it not uncommon at Puerto Limón, where I saw one among the
royal palms in Vargas Park, and several among the shrubbery about the
outlying cottages, all within a hundred yards of the Caribbean Sea. It
has been recorded a number of times from the Canal Zone, but it is not
common there. It is almost always seen in the vicinity of water."
_Winter._--Apparently the main winter range is in Colombia and perhaps
Venezuela. Referring to Magdalena, Colombia, P. J. Darlington, Jr.
(1931), writes: "The Prothonotary Warbler swarms during the winter in
the mangroves at Sevillano and in the fresh swamps at Cienaga. It was
seen also in bushes on the sea beach at Donjaca September 15, and along
the Rio Frio River in the edge of the foothills, where it was especially
common in February. The birds usually occur near water, but numbers were
noted again and again in yellow-flowering, acacia-like trees on the
border of stump land and dry forest, far from water."
DISTRIBUTION
_Range._--Eastern United States to northwestern South America.
_Breeding range._--The prothonotary warbler breeds =north= to
southeastern Minnesota (Cambridge, Lake Pekin, and La Crescent); central
Wisconsin (New London and Shiocton); southern Michigan (Hesperia,
Lansing, and Ann Arbor); northern Ohio (Toledo and Cleveland); extreme
southern Ontario (Rondeau); western New York (Buffalo and Oak Orchard);
northern West Virginia (Parkersburg); central Maryland (Seneca and
Bowie); and southern Delaware (Gumboro). =East= to southern Delaware
(Gumboro); eastern Virginia (Dyke, near Alexandria, and Dismal Swamp);
and the Atlantic coast to central Florida (Lake Gentry and Padgett
Creek). =South= to central Florida (Padgett Creek and possibly
Puntarossa); the Gulf coast to southeastern Texas (Cove, Houston, and
Bloomington). =West= to central Texas (Bloomington, Fort Worth, and
Gainesville); central Oklahoma (Norman and Oklahoma City); eastern
Kansas (Emporia and Manhattan); northwestern Iowa (Lake Okoboji); and
southeastern Minnesota (Rochester, Red Wing, and Cambridge).
The prothonotary warbler has been recorded as casual or accidental
=west= to southeastern Nebraska (Powell and Lincoln); southeastern South
Dakota (Yankton and Sioux Falls); and central Minnesota (Brainerd).
=North= to southern Ontario (London and Hamilton); central New York
(Ithaca); Massachusetts (Northampton, Amherst, and Concord); New
Hampshire (Concord); and Maine (Matinicus Island and Calais).
_Winter range._--The winter home of the prothonotary warbler is in
Central America and northwestern South America where it has been found
=north= to northwestern Costa Rica (Bolson); Nicaragua (Escondido
River). =East= to northwestern Venezuela (Mérida and Encontrados); and
western Colombia (San José de Cucuta and Villavieja). =South= to
southwestern Colombia (Villavieja); and northwestern Ecuador
(Esmeraldas). =West= to northwestern Ecuador (Esmeraldas); western
Colombia (Antioquia); western Panamá (Paracote and David); and Costa
Rica (Puntarenas and Bolson). It has been reported to occur in winter in
Campeche and on Cozumel Island, Mexico, and casually or accidentally in
Cuba (Habana), Jamaica, and St. Croix, Virgin Islands.
_Migration._--The probable route of the prothonotary warbler between its
summer and winter homes is across the Gulf of Mexico, from the Yucatan
peninsula where it occurs in both spring and fall migration. The casual
or accidental occurrences of this warbler in Cuba (Habana); Jamaica; and
St. Croix, Virgin Islands, are in migration.
Late dates of spring departure are: Colombia--Villavieja, February 5.
Panamá; Canal Zone--Barro Colorado, March 10. Nicaragua--Edén, March 23.
Quintana Roo--Cozumel, April 6. Cuba--Habana, April 4.
Early dates of spring arrival are: Yucatán--Mérida, March 28.
Jamaica--Black River, February 28. Cuba--Habana, March 31.
Florida--Pensacola, March 18. Alabama--Booth, April 4.
Georgia--Fitzgerald, March 21. South Carolina--Yemassee, March 27.
North Carolina--Greenville, April 6. Virginia--Suffolk, April 10.
Mississippi--Gulfport, March 18. Louisiana--Morgan City, March 10.
Texas--Cove, March 28. Arkansas--Huttig, March 31. Missouri--St. Louis,
April 17. Kentucky--Bowling Green, April 5. Illinois--Murphysboro, April
17. Ohio--Berlin Center, April 18. Michigan--Grand Rapids, May 3.
Iowa--Iowa City, April 26. Wisconsin--Madison, May 2. Minnesota--Red
Wing, May 7. Oklahoma--Tulsa, April 2. Kansas--Manhattan, April 26.
Nebraska--Blue Springs, April 30.
Late dates of fall departure are: Nebraska--Watson, September 1.
Oklahoma--Oklahoma City, September 14. Texas--Kemah, September 11.
Wisconsin--Racine, September 22. Iowa--Sioux City, August 31.
Michigan--Three Rivers, September 13. Ohio--Columbus, October 5.
Illinois--Oak Park, October 17. Kentucky--Lexington, October 6.
Tennessee--Elizabethton, October 19. Louisiana--Monroe, October 8.
Mississippi--Deer Island, September 27. North Carolina--Raleigh, August
26. South Carolina--Charleston, September 17. Georgia--Atlanta, October
8. Yucatán--Chichén-Itzá, October 18.