Part 10

During that same year Embody (1907) discovered Bachman's warbler breeding in Logan County, Ky., and later Holt (1920) found it nesting in Autauga County, Ala. The localities in which these birds were breeding and the locations of the nests were not very different from those described above by Wayne.

_Eggs._--The egg of Bachman's warbler is ovate and pure white, and usually glossy. The only spotted egg on record is one of a set described by Holt (1920) as follows: "The nest contained four eggs, three of them pure, glossy white, the other with a dozen minute dots of light brown, mostly about the large end; all were tinted faint salmon pink by the yolks." Three to five eggs constitute a set; three seem the usual number, with four a close second, while five are unusual.

[AUTHOR'S NOTE: The measurements of 42 eggs average 15.8 by 12.4 millimeters; the eggs showing the four extremes measure =16.6= by 12.9, 16.5 by =13.0=, =14.9= by 12.2, and 15.8 by =11.6= millimeters.]

_Plumages._--[AUTHOR'S NOTE: Two young birds, just able to fly from the nest and taken by Wayne on May 13, are thus described by Brewster (1905):

The male which is now before me may be described as follows:--Top and sides of head and fore part of back faded hair brown with a trace of ashy on the middle of crown; remainder of upper parts dull olive green; wings and tail (which are fully grown) as in the first winter plumage excepting that the greater and middle wing-coverts are rather more broadly tipped with light brown, forming two well-marked wing-bars; chin and throat brownish white tinged with yellow; sides of jugulum smoke gray, its center yellowish; sides of breast gamboge yellow shading into olive on the flanks; middle of breast, with most of abdomen, yellowish white; under tail-coverts ashy white. All the feathers on the under parts which are strongly yellow or olive, and those on the upper parts which are decidedly ashy or greenish, appear to belong to the autumnal plumage or, as it is now called, the first winter plumage, but all the other feathers on the head and body are evidently those of the first plumage. * * *

I have not seen the young female Bachman's Warbler above referred to, but Mr. Wayne writes me that "It differs from the male only in these respects: The yellow on the sides of the breast is very much paler and more restricted and the back is not greenish, but brownish. The white on the tail-feathers is merely indicated on the margins of the inner webs of the tail-feathers."

It would appear from the above that there is a sexual difference even in the juvenal plumage, and that the postjuvenal molt begins before the middle of May. This molt evidently involves all the contour plumage and the wing coverts but not the rest of the wings or the tail. The young male in first winter plumage is similar to the adult male at that season, but the crown is entirely gray, or with very little black; the feathers of the black patch on the throat, which is more restricted, are tipped with yellowish or buffy. There are no specimens available that indicate a prenuptial molt, which is probably very limited. Young males in the first nuptial plumage may be recognized by the worn and faded wings and tail.

The complete postnuptial molt of adults apparently occurs in July or earlier; I have seen no molting birds, but a large series of August birds are all in completely fresh winter plumage. In this plumage the male resembles the spring male, but the black of the crown is widely tipped with gray and the black of the breast is narrowly tipped with yellowish; these tips largely wear away before spring, although Wayne (1910) says that his "breeding males all show the olive yellow edging on the black feathers." Similar molts and changes take place in the female, but she has no black in the crown and much less or none at all on the breast; her colors are duller and she has less white in the tail, as well as olive-green, instead of yellow, lesser wing coverts.

For a full description of individual variations in plumage, the reader is referred to Mr. Brewster's (1891) excellent paper.]

_Food._--Very little information is to be found concerning the food of this warbler, but insects undoubtedly constitute its diet. Howell (1924) says: "Five stomachs of this species from Alabama contained remains of caterpillars and a few fragments of Hymenoptera, probably ants."

_Behavior._--Wayne (1907), in writing of this bird on its breeding grounds, says: "Bachman's Warbler is a high-ranging bird, like the Yellow-throated Warbler, and generally sings from the top of a sweet gum or cypress. It appears to have regular singing stations during the breeding season, and upon leaving a tree it flies a long distance before alighting. On this account it is impossible to follow the bird through the dark forest, and it can only be detected by its song. I have occasionally seen the males in low gall-berry bushes within six or eight inches of the ground, but their usual resorts are among the topmost branches of the tallest forest trees."

Brewster (1891) had similar experience with migrating birds in Florida:

Nearly or quite all that has been hitherto written about this Warbler would lead one to infer that its favorite haunts are dense thickets, undergrowth, or low trees, and that it seldom ventures to any considerable height above the ground. Our experience, however, was directly contrary to this. * * * The bird, moreover, not only frequented the tops of the tallest trees, but at all times of the day and under every condition of weather kept at a greater average height than any other Warbler excepting _Dendroica dominica_. In its marked preference for cypresses it also resembled the species just named, but unlike it was never seen in pines. * * *

At the time of our visit the Suwanee bottoms were alive with small birds many of which were doubtless migrants. They banded together in mixed flocks often of large size and motley composition. * * * Such a gathering was nearly certain to contain from one or two to five or six Bachman's Warblers.

These with the Parulas were most likely to be feeding in the upper branches of some gigantic cypress, at least one hundred feet above the earth, where they looked scarcely larger than bumble bees. * * *

The habits and movements of Bachman's Warbler are in some respects peculiar and characteristic. It does not flit from twig to twig nor launch out after flying insects in the manner of most Warblers, and many of its motions are quite as deliberate as those of a Vireo. Alighting near the end of a branch it creeps or sidles outward along a twig, and bending forward until the head points nearly straight down, inserts the bill among the terminal leaflets with a peculiar, slow, listless motion, keeping it there a second or two, and repeating the leisurely thrust many times in succession without changing its foothold. The action is like that of several other members of the genus--notably _H. pinus_ and _H. chrysoptera_--under similar conditions, and suggests the sucking in of liquid food, perhaps honey or dew. Not infrequently a bird would hang back downwards beneath a twig and feed from the under sides of the leaves in the manner of a Titmouse. * * *

Many of the hackberry trees along the banks of this stream contained compact bunches--nearly as large as a child's head--of dead leaves blackened by exposure to wind and weather. These bunches probably sheltered insects or their larvae, for they attracted several species of birds, especially the Bachman's Warblers which would work at them minutes at a time with loud rustling, sometimes burrowing in nearly out of sight and sending the loosened leaves floating down to the ground. Upon exhausting the supply of food or becoming tired of the spot--whether one of the leaf bunches or the extremity of a cypress branch--the bird almost invariably started on a long flight, often going hundreds of yards through the woods or crossing the river, instead of merely passing to the next branch or tree as almost any other Warbler would have done under similar circumstances. This habit seemed to us characteristic of the species.

Atkins wrote from Key West (Scott, 1890):

Bachman's Warbler in its habits is very much like the Parula Warbler (_Compsothlypis americana_). The resemblance is more noticeable when feeding and in search of food. The birds will then penetrate a thick bunch of leaves and go through, over and all around in the most thorough manner in their exploration after insects that appeal to their taste. They are very active, and constantly in motion. They are also quarrelsome, and resent the intrusion of other species. Frequently I have noticed them fighting away the White-eyed Vireo, and where two or more Bachman's Warblers are observed together, one is pretty sure to see them chasing and fighting among themselves. When disturbed or alarmed they are at once alert; a sharp alarm note, something like that of a Yellow-throated Warbler (_D. dominica_) is uttered, but more forcible and clear cut in its delivery. This is accompanied with a few jerks of the tail, and the bird is off to a neighboring tree. They are found alike in the trees, low bushes, and shrubbery, sometimes on or quite near the ground, and seem to prefer the heavy and more thickly grown woods to trees or bushes more in the open. Young birds are quite tame, but the adults as a rule were very shy and difficult to approach after having been once disturbed.

_Voice._--The song of Bachman's warbler is of a wiry or insect-like character, and has been widely compared by many observers to the music of the worm-eating and parula warblers and the chipping sparrow. It also resembles, according to Aretas A. Saunders (MS.), one of the songs of the blue-winged warbler. Brewster (1891) says:

The song is unlike that of any other species of _Helminthophila_ with which I am acquainted and most resembles the song of the Parula Warbler. It is of the same length and of nearly the same quality or tone, but less guttural and without the upward run at the end, all of its six or eight notes being given in the same key and with equal emphasis. Despite these differences it would be possible to mistake the performance, especially at a distance, for that of a Parula singing listlessly. The voice, although neither loud nor musical, is penetrating and seems to carry as far as most Warblers'. Besides the song the only note which we certainly identified was a low hissing _zee-e-eep_, very like that of the Black-and-white Creeper.

Widmann (1897), observing a singing male for 8 hours, says that "the bird kept singing nearly all the time at the rate of ten times a minute with the regularity of clockwork, and its sharp, rattling notes reminded me strongly of an alarm-clock. In this regard it recalls one of the performances of Parula, whose rattle is of the same length and quality, except that it has a certain rise at the end, by which it is easily distinguished."

Wayne (1910) heard one singing exactly like a prothonotary warbler, this song lasting for more than 20 minutes. And Howell (1924) mentions two Bachman's warblers, observed in Alabama, that "had the habit of singing on the wing, the song being delivered just before the bird alighted on a perch after a short flight."

_Field marks._--[AUTHOR'S NOTE: Under certain circumstances Bachman's warbler might be mistaken for a black-throated green warbler, but, fortunately, the two species do not frequent similar habitats at the same seasons. Mr. Brewster (1891) calls attention to the difficulty of distinguishing it from the parula warbler, when the two are seen against the sky in a lofty tree-top; at such times--

the chestnut throat-markings of the Parula showed quite as dark and distinct as the black cravat of the Bachman's Warbler.

The latter bird, however, was the larger or rather plumper-looking of the two, and if the upper side of the wings could be seen the absence of the white bars which are so conspicuous on the wings of the Parula Warbler was quickly noticed. * * * Of course it is only the male Bachman's Warbler which can be confounded with the Parula, for the female--setting aside occasional individuals which have black on the throat--is most like the Orange-crowned Warbler. * * * Both sexes of Bachman's Warbler habitually carry the feathers of the crown a little raised, giving the head a fluffy appearance.]

_Fall._--[AUTHOR'S NOTE: Wayne (1925) says: "The Bachman's Warbler has left South Carolina before the advent of August; the latest date I have is a young male taken by me on July 16, 1919." But he records a specimen which struck the lighthouse on Tybee Island, Ga., on September 23, 1924; he thought that this bird might have come from somewhere in the Mississippi Valley region, where the species breeds much later than in South Carolina. Atkins sent the following notes to W. E. D. Scott (1890):

Key West, Florida, 1889. First arrival from north, July 17, one adult male and one young female. Next observed July 23, three birds. Not seen again until July 31, though I was watching for them almost continually; three birds again on this date. August 4, found them more common perhaps a dozen birds in all were seen. From this time till August 25 inclusive, I found them regularly in small numbers. On August 8, 11, and 25 they were most abundant, particularly so on the first-named date, when as many as twenty-five or thirty birds were seen. After the 11th there was a decline in the numbers until the 25th, when they were again almost as numerous as on the 8th, but none were observed after the 25th.

Bachman's warbler is said to spend the winter in western Cuba and the Isle of Pines, migrating through Florida and the Keys.]

DISTRIBUTION

_Range._--Southeastern United States and Cuba.

_Breeding range._--Although Bachman's warbler was described more than a hundred years ago its range is still very imperfectly known. After its discovery near Charleston, S. C., in 1833, the bird remained unknown until rediscovered in 1886 near Lake Pontchartrain, La. The first nest was found in 1897 in southeastern Missouri, nearly the northwestern border of the range as now known. It was not until 1901 that the species was again found near Charleston and in 1905 the first young birds were collected in the same swamp where the type specimen was collected.

Bachman's warbler breeds, locally =north= to northwestern Arkansas (possibly Winslow, Big Creek, and Bertig); southeastern Missouri (Grandin, Senath, and has occurred in Shannon County); central Kentucky (Russellville and Mammoth Cave); possibly occasionally in southern Indiana, since a pair was seen throughout the breeding season at Indianapolis; north-central Alabama (Irondale); and southern South Carolina (Charleston). =East= to the coastal swamps of South Carolina (Charleston), and Georgia (Savannah). =South= to Georgia (Savannah and possibly the Okefenokee Swamp); southern Alabama (Tensas River); and southern Louisiana (West Baton Rouge Parish). =West= to southeastern Louisiana (West Baton Rouge Parish) and northwestern Arkansas (Winslow, possibly). In addition, specimens have been recorded at Fayetteville, Ark.; Versailles, Ky.; Aylett, Va.; and Raleigh, N. C.

_Winter range._--The only known wintering place for the Bachman's warbler is the island of Cuba. It has occurred in the Bahamas in fall migration. Color is given to the theory that this species may occasionally spend the winter in the deep swamps of Georgia and Florida, by the collection of a specimen in Okefenokee Swamp on December 30, 1928, and the occurrence of several in December of 1932. A specimen was collected at Melbourne, Fla., on January 27, 1898.

_Migration._--That Bachman's warbler migrates through the Florida Keys is indicated by the large number seen at Key West in fall migration and by the many that have struck the light at Sombrero Key. On March 3, 1889, 21 birds of this species struck the light and five more were killed on April 3.

Early dates of spring arrival are: Florida--Lukens, February 27. Georgia--Atlanta, April 18. Alabama--Woodbine, March 20. Mississippi--Deer Island, March 21. Louisiana--Mandeville, February 27.

In spring the latest date at Dry Tortugas Island, Fla., is April 9 and the earliest fall arrival at Key West, Fla., July 17.

Fall departure dates are: Georgia--Savannah, September 24. Florida--Key West, September 5.

_Egg dates._--Missouri: 4 records, May 13 to 17.

South Carolina: 19 records, March 27 to June 17; 10 records, March 27 to April 4.

VERMIVORA PEREGRINA (Wilson)

TENNESSEE WARBLER

PLATE 14

HABITS

Alexander Wilson (1832) discovered this warbler on the banks of the Cumberland River in Tennessee and gave it the common name it has borne ever since, although it seems inappropriate to name a bird for a State so far from its main breeding range in Canada. Only two specimens were ever obtained by him, and he regarded it as a very rare species, possibly a mere wanderer from some other clime, hence the name _peregrina_. Audubon never saw more than three individuals, migrants in Louisiana and at Key West. And Nuttall, it seems, never saw it at all. Its apparent rarity in those early days was, perhaps, due to the fact that it is inconspicuously colored and might easily be overlooked or mistaken for a small plainly colored vireo or for the more common Nashville warbler; its fluctuation in numbers from year to year in different places may also have suggested its apparent rarity. Here in Massachusetts, we have found it very common in certain years and very scarce in others.

_Spring._--Professor Cooke (1904) says: "In spring migration the Tennessee warbler is rarely found east of the Alleghenies, nor is it so common in the Mississippi Valley as during the fall migration." And he makes the rather surprising statement that "the Biological Survey has received no notes from the South Atlantic States on the spring migration of the Tennessee warbler, nor from Alabama, Mississippi, or Louisiana, though two birds were seen in April in Cuba and some were taken on the island of Grand Cayman, and the species has been noted several times in spring at Pensacola, Fla." Yet he gives April 26, 1885, as the date of its arrival at Rising Fawn, Ga. And H. H. Kopman (1905) writes:

In a small lot of warblers sent Andrew Allison, In the spring of 1902, from the lighthouse on Chandeleur Island, off the southeast coast of Louisiana, was a Tennessee Warbler that had struck the lighthouse April 13. While I had some dubious records of the occurrence of the Tennessee Warbler at New Orleans in the early part of April, it was not until 1903 that I saw the species, in spring, and then in some numbers, singing, and loitering to a degree that surprised me, for the first of these transients appeared April 26, and the last was noted May 9. They were restricted almost to one spot, a thicket of willows beside a pond in the suburbs of New Orleans. I observed others the latter part of April, 1905.

This warbler seems to be a rare spring migrant through Florida; A. H. Howell (1932) gives seven records, from Key West to Pensacola, in March and April. The few records available seem to indicate that the main migration route is along the eastern coasts of Central America (Dr. Skutch tells me that he sees it both spring and fall in Costa Rica), Mexico, and Texas to the Mississippi Valley, whence it spreads out to reach its wide breeding range. Some birds may reach Florida via Cuba, and we have some evidence that it migrates across the Gulf of Mexico. It is common on the coast of Texas in spring.

Gerald Thayer wrote to Dr. Chapman (1907) that about Monadnock, N. H., the Tennessee warbler is "very rare, and seemingly irregular. It haunts blossoming apple trees, big elms, and roadside copses of mixed deciduous second growth."

At Buckeye Lake, Ohio, according to Milton B. Trautman (1940), "the daily and seasonal numbers of no warbler species fluctuated as greatly as did those of the Tennessee Warbler. During some spring migrations it was decidedly uncommon, and never more than 5 individuals were recorded in a day nor more than 35 for the spring. During other years as many as 250 individuals (May 16, 1929) were observed in a day, and more than 800 were noted during the migration. * * * The birds in spring chiefly inhabited the upper half of the taller trees of both upland and lowland wooded areas and also the upper parts of rows or groups of tall trees along the lake shore, streams, and about farmhouses."

It must have been a very common migrant in Minnesota at one time, for Dr. Roberts (1936) writes:

Formerly, when all Warblers were more abundant than now, the little Tennessee flooded the tree-tops for a week or ten days in such numbers as to equal, if not excel, all other species put together, excepting only the Myrtle. Insignificant in size and inconspicuous in garb, it made up for these shortcomings by numbers and incessant vocal effort, indifferent performer though it is. It is still one of the commonest species. It keeps well up among the topmost branches and moves restlessly about in search of food, singing meanwhile with little apparent effort and announcing its passage from one tree-top to another by a succession of sharp little _yeap-yeaps_ that are almost as characteristic to the trained ear as the song itself.

A. D. Henderson, of Belvedere, Alberta, tells me that the Tennessee warbler is probably the most numerous of the warblers which spend the summer in the territory around Belvedere and in the Fort Assiniboine District. It breeds mainly in poplar woods, but I have also found nests in dry muskeg.

_Nesting._--Prior to the beginning of the present century very little authentic information on the nesting habits of the Tennessee warbler was available. Professor Cooke (1904) records two sets of eggs taken by one of the parties of the Biological Survey in 1901 at Fort Smith, Mackenzie, of which he says: "These eggs are among the first absolutely authentic specimens known to science." And Dr. Chapman (1907) remarked: "The Tennessee Warbler awaits a biographer." Since then, we have learned much about it, mainly through the writings of B. S. Bowdish and P. B. Philipp, who found it breeding abundantly in New Brunswick. In their first paper (1916) they describe the summer haunts and the nesting habits of this warbler as follows:

The region in question is particularly well adapted to the nesting requirements of the Tennessee Warbler, as we noted them during the above period. Extensive lumbering has removed the greater part of the large growth spruce and balsam timber, which forms the great bulk of the forests of this region, leaving areas of small trees, which, in the older clearings, have grown thickly, and to an average height of ten feet. These are interspersed with areas of more or less open, large timber, and others where the second growth has reached little more than the proportions of somewhat scattered shrubbery. The essentially level surface is frequently scored by slight depressions which form the beds of tiny streams, bordered on either side by boggy ground, dotted with grass tussocks, bushes and small trees, and overspread with a luxuriant growth of moss. Such areas are most numerous in cleared tracts, but not infrequent in the edges and the more open portions of the woods. These are the summer home-sites of the Tennessee Warbler. * * *