Part 44

Arrival dates in Georgia are similar to those in South Carolina. Around Charleston, there are comparatively few birds in evidence from November until late February, though individuals may be seen throughout this period. The barrier islands, typified by Bull's Island, seem to be favorite wintering localities. In late February the song period begins, coinciding with a distinct influx from the south, and soon the birds seem almost everywhere. Arthur T. Wayne (1910) puts the twenty-seventh of the month as the advent of the spring migration in Charleston. This coincides with all my observations, though some variation may occur when the spring is early or late.

In North Carolina the bird is much more common in the coast region than the interior, but does occur scatteringly in the middle portion of the state and sometimes considerably to the westward. It is absent in the mountains but a few may be noted in the valleys of the foothills. According to the findings of Pearson and the Brimleys (1942) it appears about Raleigh on March 9. Probably the coastal areas are visited earlier, perhaps by March 1. Uncertainty prevails regarding the arrival of birds in the western parts of the state. These authors quote T. D. Burleigh as stating that the earliest date near Asheville is March 28, 1935, and that "at no time were any seen on the mountainsides."

In Virginia one finds this warbler appearing in the Tidewater area "as early as March 20th," according to H. H. Bailey (1913). May T. Cooke (1929) states that it usually comes to the Washington region around April 15, the earliest record being March 30. Its summer status there is characterized as "local"; moist woodlands along the Potomac River are its favorite spots. Further inland, Ruskin H. Freer (MS.) says that he has seen it but twice at Lynchburg, on April 11, 1933, and September 30, 1930. Lynchburg, in the foothills of the Blue Ridge, is probably a western limit.

Professor E. A. Smyth never saw it in Montgomery County and J. J. Murray (MS.) has not recorded it about Lexington in Rockbridge County (MS.), localities in the Shenandoah Valley of Virginia. According to Dr. Murray "the bird is unknown west of the Blue Ridge in Virginia. It is a migrant in the foothills and upper Piedmont on the eastern side of the Blue Ridge. From Washington south through central Virginia it is an uncommon summer resident in the eastern third of the State, becoming more common as the coast is approached, but even in the tidewater region and on the Eastern Shore it is abundant only locally."

My experience with this warbler in Virginia is limited to the southern portion of the Eastern Shore. There, in the area about Eastville, Cheriton, and Cape Charles during June and half of July 1940, I found it fairly numerous in the woodlands but discovered no nests. This locality appears to be the extreme northern limit of the Spanish moss for only a few bedraggled clumps were noted in the woods near Eastville on the Chesapeake Bay side of the peninsula. This moss ceases to be prevalent as one comes to the bay on the Norfolk side and the dejected evidences of the growth across that body of water suggest that it may have had its origin in wind-blown shreds that gained and maintain a precarious foothold.

_Nesting._--It is in its domestic habits that _dominica_ exhibits its unalterable affinity for _Tillandsia usneoides_ where the ranges coincide. The nest is rarely placed anywhere except in a clump of it, and the tree concerned is usually an oak, as this species offers more foothold for the Spanish moss than others and, as a consequence, is more heavily draped. Although I have found nests both in pines and cypresses, there is little question but that the live oak holds them more often than any other tree. The long plantation avenues are splendid sites, and Arthur T. Wayne once told me that he had climbed every tree in the long approach to Oakland Plantation in Christ Church Parish near Charleston, for nests of this bird!

The height at which the nest is placed varies from 10 or 12 feet to 50 or 75, and in some cases to nearly 100. The lowest nest I ever found was in my yard (in 1943); it was built in a clump of moss in a cassina bush (_Ilex vomitoria_) barely 3-1/2 feet from the ground. However, the average height might be put at about 35 feet.

Nest building materials are not of wide choice, usually consisting of fine grasses, caterpillar silk, weed stems, and plant down, with a lining of plant down or sometimes feathers. The moss among which the nest is suspended is woven into the structure to some extent. Horsehair and skeletonized leaves are sometimes employed. The nest is fairly deeply cupped and averages about 3 inches in outside diameter, 2-1/2 in inside diameter, and the same in depth. The writer has never seen a nest not built in moss, but Wayne (1910) gives two other locations in coastal South Carolina, his only such in 50 years of field work. Both were in short-leaf pines, one 45 and the other 50 feet up, and both were hidden in masses of needles and burs, invisible from below. One of these nests is in the Brewster collection and the other in J. E. Thayer's.

Dr. E. E. Murphey, writing of the bird in the Savannah River Valley of Georgia (1937), states that it prefers moss "whenever it is present" but adds, "contrary to the experience of Arthur T. Wayne in the coastal area, it breeds also in pine woods which at places come very close to the margins of the swamps * * * Here the Yellow-throated Warbler nests not uncommonly, building far out on the end of the horizontal limbs, well concealed by the needles." He states that "two broods are usually reared." W. H. LaPrade, Jr. (1922) describes the nesting in the Atlanta area as similar to that noted by Dr. Murphey about Augusta. In the coastal strip and the offshore islands conditions identical with those in South Carolina prevail.

In the latter State birds are usually mated by March 11. Nest building is begun by the middle of the month unless the season is delayed or adverse weather hinders operations, in which case nests are not found at times until early April. Georgia and Florida nestings correspond closely. In areas where Spanish moss is not found, _dominica_ reverts to saddling its nest on the horizontal branches of trees. Pearson and the Brimleys (1942) state that in the Raleigh, N.C., area the nest is frequently constructed in pines "at a height of from 20 to 40 feet." They also say that in the coastal region where the cypress occurs the bird "frequently nests in the long, gray moss hanging from the trees." North Carolina nesting commences in late April.

The nest is constructed mostly by the female, sometimes completely so, but D. J. Nicholson (1929) has seen the male assisting in Florida. In the spring of 1942 a nest was built in a banner of moss no more than 20 feet from the porch of my home, at the extremity of a drooping live-oak limb. The female brought material as often as twice a minute, disappearing completely within the moss clump which could be seen bulging now and then with her movements. She was utterly unconcerned by observers on the porch, even the noise made by children not disturbing her in the least. The male sang constantly nearby.

Two broods are raised in coastal South Carolina. The young of the first are fully fledged by April 22, according to Wayne. The second nest is begun soon after the first brood is away. The yellow-throated warbler will, of course, lay again if accident befalls the nest and eggs. Little time is lost in the interim and illustrative of this tenacity of purpose are some interesting notes of C. S. Brimley (1943) dealing with experiments made by him and his brother, H. H. Brimley of Raleigh, N. C. On April 25, 1890 they collected a set of four eggs from the nest in a pine tree, 42 feet up. Four days later (April 29) another nest was being built in a smaller pine nearby, at an elevation of 47 feet. On May 12 a set of eggs was taken from it and three days later (May 15) the birds again began to build, this time in a very slender pine which had to be stayed with ropes when eggs were removed from the nest on May 26. Two days later the fourth nest was started in a large pine, 44 feet up. On June 7 additional eggs were secured. All sets consisted of four eggs. No further attempts were made on this persevering pair but "they may have built a fifth nest * * * for all we know to the contrary."

Although it seems remarkable that Audubon apparently failed to remark particularly on the moss-nesting habits of this warbler, it will be recalled that his observations seem to have been made largely in Louisiana, for he stresses this State in his account of the species; but he could hardly have failed to observe it elsewhere in the South, particularly on his visits to Rev. John Bachman in Charleston. Of the nest Audubon (1841) says that it is "placed on a horizontal branch of a cypress, twenty, thirty, or even fifty feet above the ground, and is with difficulty discerned from below, as it resembles a knot or a tuft of moss." Certainly, moss is abundant in Louisiana and it would seem that the birds there share this preference despite the fact that the form of this warbler found there is _albilora_.

_Eggs._--[AUTHOR'S NOTE: Dr. Chapman (1907) says that the yellow-throated warbler lays 4 or 5 eggs, but very rarely 5, and adds:

"Ground color a dull greenish gray-white, in a large series the peculiar color of the markings seem to tinge the ground color; the markings are very mixed, numerous under shell marks, in the form of blotches and specks, of pale lavender and purplish gray overlaid with heavier surface markings of wine-red, umber and deeper shades of purplish gray and blackish. The heaviest markings are at the larger end, which is sometimes well wreathed, with many spots and specks over rest of egg." The measurements of 50 eggs average 17.1 by 13.0 millimeters; the eggs showing the four extremes measure =19.0= by 13.6, 17.6 by =14.0=, =15.4= by 12.7, and 16.0 by =11.9= millimeters.]

_Plumages._--[AUTHOR'S NOTE: Dr. Dwight (1900) describes the juvenal plumage, in which the sexes are apparently alike, as "above olive-brown with dull black streaking. Below, dull white, streaked with clove-brown chiefly anteriorly." A postjuvenal molt, beginning early in June in Florida, and involving the contour plumage and the wing coverts but not the rest of the wings or the tail, produces the first winter plumages. These are much like those of the adults, but are generally more brownish, the female being browner than the male. The yellow throat is assumed at this molt.

The first nuptial plumage is acquired by wear, the brownish wash wearing away and the back becoming grayer and the black markings clearer. Young birds are now indistinguishable from adults, except by the browner and more worn wings.

Adults have one complete postnuptial molt in midsummer, after which the fully adult plumage is assumed, the colors of the female being similar to those of the male but duller.]

_Food._--The food of the yellow-throated warbler has apparently not been well investigated. Little appears in the literature, an illustration of the need to learn more of the diet of small, woodland birds. Records of the examination of seven stomachs reveal that insects compose most of its diet, for according to Howell (1932) "beetles, moths and their larvae, flies, bugs, grasshoppers, grouse locusts, crickets, scale insects, and spiders" are included in the food. Witmer Stone (1937) in writing of the first observance of this warbler at Cape May Point, N. J., on July 13, 1920, states that he saw it take "a green caterpillar about an inch in length." D. J. Nicholson has noted (1929) that while watching one of these birds in Volusia County, Fla., he saw it eat at least ten "worms" in a few minutes as it searched the trees near where he sat.

I have often watched these warblers feeding in my yard and have seen them take small, active caterpillars on numerous occasions. There seems little doubt that scale insects are often taken, as the yellow-throated warbler, creeping about the limbs of trees as it does, undoubtedly finds many of these tiny, but destructive pests. There can be little question as to its benefit to agriculture.

_Behavior._--There is much that is reminiscent of the brown creeper in the habits of the yellow-throated warbler. Its actions are deliberate and methodical, with none, or very little, of the nervous energy so characteristic of many species of _Dendroica_. As a result it is easier to watch than many other warblers, and its technique of hunting frequently brings it close to the observer. Pearson and the Brimleys (1942) state that it confines its creeping search to the limbs of trees, omitting the trunks altogether. However I have seen this warbler in my yard, feeding on the trunks of both pines and oaks. In this posture, it acts almost exactly like the black-and-white warbler (_Mniotilta varia_) and the brown creeper (_Certhia familiaris_). D. J. Nicholson of Orlando, Fla. (1929), mentions that he has seen them feeding on the "mossy trunks" of trees.

Milton P. Skinner (1928) writes:

Yellow-throated warblers are gentle and friendly, but are not really socially inclined, either toward other members of their own kind or toward other species. * * * In the trees, their movements are quick, nervous and active, and they are very neat and trim in appearance for they spend much time in preening * * * As usual with warblers, these little birds are skillful insect catchers, and eat house flies, mosquitoes, ants, crickets, beetles and many other varieties of the smaller insects. Once I saw one on an artificial feeding station eating bread crumbs.

These warblers seem even fonder of bathing than most other warblers. They go regularly and often to their baths, and after bathing they spend several minutes carefully preening their feathers.

_Voice._--The song of the yellow-throated warbler is one of its distinctive characteristics. Completely unlike the thready, insect-like notes of many of its family, it is difficult to describe verbally, and interpretations of it must necessarily vary according to impressions made on human ears. That it is loud, with a definitely ringing character, is agreed upon by all, and in this respect resembles the beautiful song of the prothonotary warbler (_Protonotaria citrea_) another dweller of the cypress lagoons.

R. T. Peterson (1939) says that the song is "slightly suggestive" of those of the indigo bunting (_Passerina cyanea_) and the Louisiana water-thrush (_Seiurus motacilla_), although I had not noticed this resemblance, and describes the notes as "starting with several clear, slurred notes and dropping slightly down the scale." This is true; the preliminary or "clear" notes vary in number from five to eight, and are run together at the end. F. M. Weston (MS.) says that there are "several distinct repetitions of a single note, ending weakly in an anticlimax trill," also a satisfactory description. Rendered into words (always inaccurate and often misleading) it has been written as _ching-ching-ching-chicker-churwee_. F. M. Chapman (1907) remarks that he was familiar with the song for some years before being impressed with its resemblance to that of _S. motacilla_, and follows with the statement that it is not so much the form of the notes themselves "as their wild, ringing, carrying quality which recalls the song of the water-thrush," in which quality a resemblance is readily understandable, and further says that the song has been compared to that of the indigo bunting "not without reason." Howell (1932) simply characterizes it as "loud and attractive," and also compares it with that of the indigo bunting and the water-thrush.

Aretas A. Saunders (MS.) writes: "The song is bright, musical and lively, beginning with high-pitched two-note phrases, sounding something like _cheeka-cheeka-cincha-cincha_, and then dropping down in pitch in a series of rapid notes. It is fairly loud, with a clear ringing quality." This is much the best description I have seen of this highly individual song.

This warbler is an indefatigable songster. From early March through May (about Charleston) it sings almost incessantly, practically from dawn to dusk. Often only seconds intervene between the renditions. As June approaches, the frequency of its singing drops sharply, and by the middle of that month only a very occasional song is heard.

_Enemies._--The yellow-throated warbler is open to the various dangers which beset any of the smaller passerine species, but I know of no single enemy that operates against it particularly. However, it occasionally falls into a somewhat novel trap, becoming entangled in tough spider-webs. In much of the cypress country of the southeast the large Carolina silk spider makes its home and spins a magnificent golden web high up amid the straight-trunked columns of the trees. Some of these webs may stretch for many yards and on two occasions I have seen this warbler caught therein. In one instance it was the convulsive fluttering of the bird, apparently stationary in midair, which attracted attention and after some moments of violent activity, it succeeded in breaking the strands which held it. In the other, a dead specimen was found inextricably entangled. Although two experiences such as this are by no means conclusive of any marked mortality, it at least indicates that this may occur more often than one would realize.

_Field marks._--The brilliant yellow throat is always diagnostic and is usually readily seen because of the bird's tameness and deliberate actions. The grayness of the plumage is also apparent. A brief glimpse is enough to establish its identity, even if the characteristic song is unfamiliar.

_Fall._--The yellow-throated warbler leaves the northern portions of its range rather early. A very late specimen in the northern perimeter of the range was found dead by J. K. Potter (MS.) at Collingswood, N.J., on November 2, 1943. According to H. H. Bailey (1913) departure dates for southeastern Virginia are in the "latter part of July." May T. Cooke (1929) gives the latest occurrence about Washington as September 11, 1927. Near Lynchburg, R. H. Freer (MS.) has seen it once on September 30. These are all considerably later than Bailey's late July, and though very late, dates indicate that the species may remain in Viriginia well into August. C. W. Richmond and J. D. Figgins secured specimens on July 28, 1889, at Four Mile Run (near Washington), these being noted by William Rives (1890) in his catalog of Virginia birds.

Late September sees the last migrants leaving central and western North Carolina; the twenty-fifth of that month in the Raleigh area and the twenty-eighth in the Asheville region (Pearson and the Brimleys, 1942). In the coastal area the average is probably a little later.

From South Carolina southward, as already noted, the species is a permanent resident though the scattered wintering individuals are quite probably birds that nested in the northern portion of the range. About Charleston birds can be seen through July and August, but being quiet are not nearly so noticeable, and their numbers fall off in September and October. The young appear to leave much earlier, indeed, shortly after the cessation of the song period in mid-June, though doubtless early July sees some of them still here.

In Florida I have not seen this warbler south of the Lake Okeechobee-Kissimmee Prairie region in winter but occasional individuals are seen there throughout January and February in the "hammocks" and they begin to sing in early March. In the western part of the state F. M. Weston writes from Pensacola that the "fall migration is hardly noticeable in this region, for the birds have been silent and inconspicuous since June, and the migratory movement consists merely of a quiet withdrawal from the area." Of its winter status in that area he follows with the statement that the "yellow-throated warbler winters regularly in small numbers, at which season it is confined to the live oak groves. In order to find it, an observer must scan carefully every chickadee-titmouse group found in suitable situations. The composition of such a group would be half-a-dozen each of the tufted titmouse, Florida chickadee, myrtle warbler and ruby-crowned kinglet, a blue-gray gnatcatcher, a blue-headed vireo, an orange-crowned warbler and one or two yellow-throated warblers."

Alexander Wilson (1832) in speaking of the first specimen of this warbler he ever saw (in Georgia) stated that it was late in February and was the first spring appearance of the species in that area, following this at once with the explanation that "they leave the U. S. about three months during winter and, consequently, go to no great distance." He was in one of his few errors here for the warbler is, as we have abundantly seen, present in southeastern United States through the whole of the winter.

DISTRIBUTION

_Range._--Southeastern United States to Panamá and the West Indies.

_Breeding range._--The yellow-throated warbler breeds =north= to northern Illinois (Knoxville, Hennepin, Saint Charles, and possibly Waukegan); northern Indiana (Elkhart and Waterloo); northern and eastern Ohio (Wauseon, Sandusky, Cleveland, and Cadiz); northern West Virginia (Doddridge County); northern Maryland (Baltimore); and southern Delaware (Seaford and Frankford). Its occurrence, without indication of breeding has been reported north to Sigourney, Iowa; Lake Koshonong and Racine, Wis.; Kalamazoo, Battle Creek, and Detroit, Mich.; Frankfort Springs and Narberth, Pa.; Mamaroneck, N. Y.; Hartford, Conn.; and Dedham, Mass. =East= to southeastern Delaware (Frankford); and the Atlantic coast to central eastern Florida (Titusville). =South= to south-central and western Florida (Titusville, Bassinger, Punta Rossa, Tarpon Springs, St. Marks, and Pensacola); the Gulf coast of Mississippi and Louisiana to eastern and central Texas (Port Arthur, Houston, Brazoria County, San Antonio, and Ingram). =West= to eastern Texas (Ingram, Austin, Waco, Rhome, and Gainesville); central Oklahoma (Dougherty, Oklahoma City, and Ponca City); southeastern Kansas (Neosha Falls), central Missouri (Columbia); and western Illinois (Knoxville).

The territory as outlined is occupied by two geographic races: the eastern yellow-throated warbler (_D. d. dominica_) breeds from Maryland southward and east of the mountains; the sycamore yellow-throated warbler (_D. d. albilora_) breeds from the mountains westward.

_Winter range._--The two races appear not to mingle in winter. The yellow-throated warbler winters =north= to northwestern Florida (Pensacola and St. Marks); and casually to southern Georgia (Thomasville and Brunswick). =East= to southeastern Georgia (Brunswick); the Bahamas (Watling and Great Inagua Islands); Dominican Republic (Samaná); Puerto Rico; and St. Thomas; casually to Montserrat. =South= to Montserrat, casually; Haiti (Port au Prince); and Jamaica. =West= to Jamaica; Grand Cayman; western Cuba (Isle of Pines and Habana); and western Florida (Pensacola).

The sycamore warbler winters regularly =north= to southern Sinaloa (Mazatlán); Nayarit (Tepic); southern Veracruz (Tlacotalpan); Yucatán (Progreso); and Quintana Roo (Cozumel Island). =East= to Quintana Roo (Cozumel Island and Xcopén); British Honduras (Belize); central northern Honduras (Ruatán Island and Puerto Castilla); southeastern Nicaragua (Greytown); and central Costa Rica (San José and Cartago). =South= to Costa Rica. =West= to western Costa Rica (Cartago); western Guatemala (Dueñas and Totonicopán); western Guerrero (Acapulco); western Michoacán (Coahuayana); Colima (Colima); and southwestern Sinaloa (Mazatlán). It also winters in small numbers in Cameron County, Tex.