Part 80

PLATE 44

HABITS

This western form of the yellow-throated warbler makes its summer home in the Mississippi Valley, from southern Wisconsin and southern Michigan southward, and it winters in Mexico and Central America. Although its winter range is so widely separated from that of the eastern form and its summer range, mainly west of the Alleghenies, is quite distinct, the two forms are very much alike in characters and habits. Ridgway (1902) describes it as similar to the yellow-throated warbler, "but with much smaller bill, the superciliary stripe more rarely yellow anteriorly, and with white areas on inner webs of lateral rectrices averaging decidedly larger."

Allison wrote to Dr. Chapman (1907) that in southern Louisiana, "it has a strong liking for woods shrouded in heavy festoons of Spanish moss, and, therefore, keeps much to the cypress swamps; but it is common in the less damp woods in the same regions; on the northern shores of Lake Pontchartrain it spreads slightly from the cypress swamp into the pines. It is essentially a bird of the larger trees, and swampy forest may be considered its typical habitat." M. G. Vaiden, of Rosedale, Miss., tells me that he always looks for the sycamore warbler in the cypresses, and that it is seldom found elsewhere, except on migrations.

Ridgway (1889) says of its haunts in Illinois: "The Sycamore Warbler is a common summer resident in the bottom-lands, where, according to the writer's experience, it lives chiefly in the large sycamore trees along or near water courses." In Indiana, according to A. W. Butler (1898), "the Sycamore Warbler does not depart from the vicinity of streams, even following small creeks, along which sycamores grow, for quite a distance towards their source. They seem to prefer these trees, spending much time among their highest branches, but they may also be found among all the trees fringing waterways, sometimes quite near the ground, and often are seen among our orchards, lawns, and even the shade trees along the streets of towns in the valleys."

It seems to be partial to the large, picturesque, stream-loving sycamores in other parts of its range, as far north and east as Michigan and Ohio, thus deserving its well-chosen name. In many places these fine trees have disappeared, and the warblers have become scarce or have gone entirely.

Spring.--The sycamore yellow-throated warbler is one of the earliest wood warblers to enter the United States from its winter home, arriving in Louisiana around the first week in March, reaching Indiana about the middle of April, and appearing in Michigan as early as April 20. In Ohio, according to Dr. Wheaton (1882), "this is the first of the family to arrive in spring. It is always to be seen before the Yellow-rumped and Yellow Warblers make their appearance, sometimes before the last snow and ice. I have seen them in considerable numbers on the 13th of April, and have known of its occurrence as early as April 9th. When on their migrations they confine themselves almost exclusively to the trees which skirt the streams, and move northward by day with considerable rapidity."

The main migration route seems to be almost directly northeastward, from western Mexico and Central America to western North Carolina and Ohio, and more directly northward through the broad Mississippi Valley to Michigan and Wisconsin. This is markedly different from the migration route of the eastern race, which migrates nearly northward along the Atlantic coast.

Nesting.--Whether the nest of the sycamore warbler is in a cypress or in a sycamore, it is always placed at a considerable height from the ground, for this is a tree-top bird. Nests have been recorded at heights ranging from 10 to 120 feet above the ground, but probably most of them are between 30 and 60 feet up. Mr. Butler (1928) describes two Indiana nests of similar construction. One was--

built about 35 or 40 feet above the ground in a flat crotch, on an approximately horizontal limb of a large sycamore tree. * * * The nest measures as follows: Outside diameter 2.50 inches; inside diameter 1.65; outside height 2 inches; inside depth 1.75 inches. The heavier frame was composed of shreds of grapevine bark, bits of the covering and coarser fibre of weeds, mingled with which were many small pieces of cotton cord or ravelings. The nest was lined and its entire bottom was composed of the soft down obtained from dry sycamore balls. In fact the nest really had no foundation for the bottom, the lining material reaching through to the limb. [The other] was about 75 feet above the ground in a crotch of small branches toward the end of a sycamore limb which was not strong enough to bear one's weight. It was so hidden by the foliage that it could not be seen until some of the leaves fell this autumn.

A set of four eggs is in the Richard C. Harlow collection, taken by W. C. Avery, Greensboro, Ala., April 24, 1893. The nest was in a liquidambar tree, 26 feet up and 9 feet out from the body of the tree, on a horizontal branch and nearly concealed in the Tillandsia in which it was built. George Finlay Simmons (1925) says that in Texas the nests are sometimes built in an elm or a pecan tree, from 12 to 35 feet from the ground.

Eggs.--The sycamore warbler lays from 3 to 5 eggs; in most cases 4 eggs seem to complete the set. Mr. Simmons (1925) describes them as "dull greenish gray-white; marked with distinct and clouded blotches, specks, and under-shell markings of lavender, purplish-gray, umber, and brownish-red; and sometimes even blackish spots; usually wreathed about the larger end." The measurements of 10 eggs average 16.9 by 12.7 millimeters; the eggs showing the four extremes measure =17.6= by =12.1=, =16.2= by 12.8, and 16.6 by =13.0= millimeters.

Plumages.--The sequence of plumages and molts is probably the same as for the yellow-throated warbler.

Food.--Very little seems to have been published on the food of this warbler, but it probably does not differ materially from that of the other wood warblers. Professor Aughey (1878) found remains of 15 locusts and 24 other insects in the stomach of one collected in Nebraska. A. H. Howell (1924) says: "Examination of 9 stomachs of this bird from Alabama showed its food to be mainly flies, beetles, ants and other Hymenoptera, and spiders."

Behavior.--Ridgway (1889) says that "in its motions, this warbler partakes much of the character of a creeper, often ascending or descending trunks of trees or following their branches, much in the manner of a Mniotilta." Butler (1898) says that "its longer flights much resemble those of the Chipping Sparrow. Its shorter ones, as with quivering wings it beats rapid strokes when moving from limb to limb, remind one of the movements of the Kingbird." Referring to its general habits in Texas, Simmons (1925) says it is:--

observed singly or in pairs, moving very slowly about in the tops of the trees, particularly the sycamores along streams, carefully keeping limbs and branches between itself and any chance observer. Movements very deliberate, sometimes stopping for several minutes, creeping along by small hops, among upper branches, never on trunks or larger limbs; thus, in actions, strikingly different from most members of the warbler family. Usually keeps to the tops of the tallest trees; hops from one perch to another very slowly; occasionally comes down among the lower branches. Usually quiet, the song being uttered at wide intervals; however, at times in spring it may be heard almost constantly singing.

Voice.--Butler (1898) writes: "The song of the Sycamore Warbler, as I catch it, is as follows: Twit, che-e, che-e, che-e, che-e, che-e, che-á. This is about its usual length. The first syllable is abrupt, with rising inflection, then, after a slight pause, the remainder is uttered at the same pitch until the last syllable, which ends sharply with a slight rise in tone. The whole song is very unique. Its notes are clear and distinct, and it is pitched in such a key that it may be heard under favorable circumstances over a quarter of a mile."

Mr. Allison wrote to Dr. Chapman (1907) as follows: "The call-note is a rather lively chipping, like that of an agitated Parula Warbler, or perhaps somewhat more like that of Pine Warbler. The song is like the Indigo Bunting's, much softened, and with a falling cadence all the way through; thus: See-wee, see-wee, see-wee, swee, swee, swee, swee--the last four notes uttered more rapidly, but becoming fainter, until the last one is very indistinct."

Mrs. Nice (1931) writes: "The songs of this lovely warbler made one think of evergreen forests; they gave a wistful, haunting touch to the somber, leafless woods, where most of the bird notes were loud and ringing. The bird in the Oliver's woods in 1927 had two songs. 'A' was in a continuously descending scale except for the last note which was slightly higher than that preceding--see see see see see see chérwer; the ending was abrupt. 'B' was more musical; it consisted of four notes on the same pitch, then three descending, ending with one on a somewhat higher pitch. Both songs were given five and six times a minute."

Winter.--Dr. Skutch contributes the following note: "The sycamore warbler is a rare winter resident in Central America, infrequently recorded in both the highlands and the Caribbean lowlands. Although Griscom states that in Guatemala it is a common winter visitant, the statement scarcely seems supported by the paucity of published records. Carriker knew of but one specimen taken in Costa Rica. I have myself seen this bird only thrice during 12 years in Central America. On January 22, 1935, I found one in a flock of Townsend's and black-throated green warblers in the pine woods on the Finca Mocá, on the Pacific slope of Guatemala at 3,500 feet. My one Honduran record is of a bird seen among the coconut trees by the shore at Puerto Castilla, on January 27, 1931. Peters secured a single specimen from a coconut palm near Tela, in the same general region, on January 18, 1928. In Costa Rica, I found one of these rare warblers in the garden of the hacienda Las Cóncavas, near Cartago, at 4,600 feet above sea-level, on November 3, 1935.

"Griscom's record of the sycamore warbler at San Lucas, Guatemala, on August 7, indicates early arrival. The single published Costa Rican date is of a bird collected by Underwood at San José on September 17. The date of the spring departure appears to be quite unknown."

DENDROICA GRACIAE GRACIAE Baird

NORTHERN GRACE'S WARBLER

HABITS

This pretty little warbler was discovered by Dr. Elliott Coues (1878) and named by him in honor of his sister and for whom, as he expresses it, "my affection and respect keep pace with my appreciation of true loveliness of character." Of its discovery, he states: "While journeying through New Mexico, en route to Fort Whipple, Arizona, in July, 1864, I found Grace's Warbler on the summit of Whipple's Pass of the Rocky Mountains, not far from the old site of Fort Wingate, and secured the first specimen on the second of the month just named." He afterwards found it to be "the most abundant bird of its kind, excepting Audubon's Warbler," in the pine forests on the mountains of Arizona, and says that Henshaw found it to be "one of the commonest of the summer Warblers in the White Mountains. * * * His observations confirm my own in regard to the pine-loving character of the birds; he found them almost invariably in coniferous forests, passing swiftly along the smaller branches of these tall trees, or darting into the air to capture passing insects; and even in August, when various families had united into small flocks, and were lingering in company with other insectivorous birds, before their departure for the South, their preference for their native pines was still evident."

I found it fairly common in the upper reaches of Ramsey Canyon in the Huachuca Mountains of Arizona, among the tall, scattered yellow pines, at elevations between 6,000 and 7,000 feet, where a nest with young was found on June 4, 1922. Swarth (1904) found it more common there as a migrant than as a breeding bird and rather irregular in its abundance.

Grace's warbler, now well-known as a summer resident in the mountains of southern Colorado, New Mexico, Arizona, Sonora, and Chihuahua, is apparently closely related to the yellow-throated warbler of the southern States and to Adelaide's warbler of Puerto Rico; it has a slightly differentiated subspecies in Central America.

Nesting.--What is probably the first authentic nest of Grace's warbler to be reported was taken in Yavapai County, Ariz., on June 23, 1890, by H. Keays for H. P. Attwater. This nest is described by Samuel B. Ladd (1891) as "placed on limb of pine sixty feet from the ground. Nest very compact; outside diameter 3 in. by 1-1/2 in. high; inside diameter 1-3/4 in. by 1-1/4 in. deep. The body of this nest is composed of horse-hair, strings and vegetable fibres. The most abundant vegetable material interwoven consists of the staminate catkins and bud scales of Quercus emoryi. There is also some wool, vegetable down, and insect webbing, in which are entangled the exuviae of some caterpillar. Attached on the outside was a small staminate cone of a species of Pinus. Nest well lined with feathers and horse-hair."