Front matter (continued 5)

Field marks.—There are no very striking marks on Lucy’s warbler; it is clothed in quiet colors and in general appearance suggests a warbling vireo. The chestnut crown patch of the male can be seen under favorable conditions, but on the female it is seldom in evidence. The chestnut upper tail coverts can be seen only when the bird is in certain positions. Its activity will mark it as a wood warbler, and it is the only one of this family likely to be found on its breeding grounds among the mesquites in the nesting season.

Enemies.—Mr. Howard (1899) says that “many nests are destroyed by wood-rats and snakes.” And Mr. Dawson (1923) writes:

Dwarf Cowbirds are prominent in the formidable host of enemies which this tiny bird must face. Sometimes the warblers are able to entrench themselves behind apertures so narrow that the Cowbird cannot get in; and once we saw the Cowbird’s foundling resting unharmed, but also harmless, upon the “doorstep,” not less than two inches distant from the warbler’s eggs. Another nest, more exposed, contained three eggs of the arch enemy, and had been deserted by the troubled owners. The Gila Woodpecker is an especially persistent enemy. Accustomed as he is to poking and prying, he seems to take a fiendish delight in discovering and devouring as many Lucy Warblers’ eggs as possible. We caught several of these villains red-handed, and we found reason to believe that more than half of the nests in a certain section had been wrecked by them. Add to these the depredations of lizards, snakes, and, possibly, rats, and the wonder is that these tiny gray waifs are able to reproduce at all.

DISTRIBUTION

Range.—Southwestern United States to central Mexico.

Breeding range.—Lucy’s warbler breeds north to southern Utah (Beaverdam Wash, Zion National Park; Calf Creek, Garfield County; and the San Juan River); and southwestern Colorado (Montezuma County near Four Corners). East to Colorado (near Four Corners); western New Mexico (Shiprock, possibly San Antonio, mouth of Mogollon Creek, and Redrock); southeastern Arizona (Bisbee); and northeastern Sonora (Moctezuma). South to northern Sonora (Moctezuma and Sáric); southern Arizona (Baboquivari Mountains, Menager’s Dam, and Gadsden); and southern California (Picacho and Silsbee). West to southern California (Silsbee, Mecca possibly, and Chemehuevis Valley); western Arizona (Fort Mojave); and southwestern Utah (Beaverdam Wash).

Winter range.—The few available records place the winter home of Lucy’s warbler in central western Mexico from Jalisco (Bolaños and Lake Chapala) to eastern Guerrero (Iguala).

Migration.—Few migration dates are available for a species with such a limited range. Early dates of arrival are: Arizona—Tucson, March 12. California—Mecca, March 29. Utah—St. George, March 23. A late departure date is: Arizona—Tombstone, October 3.

Egg dates.—Arizona: 58 records, April 22 to June 27; 30 records, May 2 to 21, indicating the height of the season.

PARULA AMERICANA PUSILLA (Wilson)

NORTHERN PARULA WARBLER

Plates 20, 21

HABITS

I have always preferred the old name, blue yellow-backed warbler, as originally used by Wilson and Audubon, to the modern common name; it seems more descriptive of this dainty wood warbler. As to the origin of this newer name, Dr. Spencer Trotter (1909) writes: “The name ‘parula’ recently in vogue for the warblers of the genus Compsothlypis is clearly borrowed from the old Bonaparte genus Parula (diminutive of titmouse). The bird (C. americana) has appeared under various titles—‘the Finch Creeper’ of Catesby (I, 64), ‘the various coloured little finch creeper’ of Bartram (Travels, 292), and the ‘Blue Yellow-backed Warbler’ of Wilson, Audubon, and later authors.” Parula was extensively used as the generic name during the last century, and is now reinstated to replace Compsothlypis.

The 1931 A. O. U. Check-List of North American Birds recognizes only two races of this species, the subject of this present sketch, P. a. pusilla, and the southern race, P. a. americana. The two forms together occupy a breeding range covering practically all of the United States east of the Great Plains, as well as parts of southern Canada, the type name being restricted to the birds breeding from the District of Columbia southward to Alabama and Florida.

Ridgway (1902) describes the northern bird as “similar to C. a. americana, but slightly larger, with smaller bill and darker, richer coloration; adult male with blue of upper parts deeper, and black of lores more intense; lower throat or upper chest (sometimes both) blackish or dusky (the feathers sometimes tipped with chestnut), forming a more or less distinct, often very conspicuous band; lower chest orange-tawny, tawny, or chestnut (the feathers usually margined with yellow) forming usually a distinct and often abruptly defined patch; sides usually more or less tinged or spotted with chestnut.”

In the same work, he describes a third form, C. a. ramalinae, as “similar in coloration to” the northern bird, “but smaller even than C. a. americana.” He gives as its range the Mississippi Valley, from Mississippi, Louisiana, and Texas to Minnesota and Michigan. This western race is not recognized in the 1931 A. O. U. Check-List.

Our experience with the northern parula warbler in Bristol County, Mass., well illustrates the successive changes that nature and man have wrought in the distribution of so many of our birds. Many years ago, perhaps early in the last century or before, some hardy pioneers hewed out a clearing in the forest that clothed the slopes of Rocky Hill in Rehoboth, Mass., planted an apple orchard, and surrounded it with stone walls. All traces of the old farm, if ever there had been one, disappeared before I first visited the locality in 1888, and the forest had begun to encroach on the old clearing. The apple trees even then showed signs of old age and were profusely covered with long festoons of that picturesque tree lichen, often called beard-moss or old-man’s-beard (Usnea barbata, U. longissima, or U. trichodea). This old orchard was a mecca for all local oologists, and many a set of eggs of the blue yellow-backed warbler was taken from it during succeeding years. As time passed, the old trees gradually died, the Usnea disappeared, the warblers ceased breeding there, and the forest eventually reclaimed the land until today only the ancient stone walls remain to mark the locally famous haunt of the blue yellow-backs.

I can remember several other old, neglected orchards that were similarly decorated with the long, gray-green lichen and that were inhabited by parula warblers as nesting sites, but they all suffered the same fate; the orchard trees decayed and were replaced by woods and thickets. During the early part of the present century this warbler continued to breed commonly in Bristol County wherever it could find trees infested with Usnea—around the edges of swamps and along the shores of ponds, lakes, and sluggish streams; but now this lichen seems for some reason to have entirely disappeared from the County, and the parula warbler has likewise disappeared, although it may still breed in a few similar localities on Cape Cod, Mass., where I have found it a few times in more recent years.

Localities such as those described above seem to be typical of the breeding haunts of the northern parula warbler, at least in New England, southern New York, and New Jersey. Whether the presence of Usnea is a sine qua non for the breeding haunts of this wood warbler is an open question; but it may safely be said that where this lichen grows in abundance one is almost sure to find it breeding; and conversely, where this lichen is scarce or lacking, the warbler breeds sparingly or not at all.

Farther westward, northward, and southward, where Usnea is scarce or entirely absent, these warblers seem to find congenial haunts in hemlock ravines and in other coniferous woods and swamps; but even there they are more likely to be found where there is at least some of one species or another of this lichen, or where the somewhat similar Spanish moss (Tillandsia usneoides) grows.

Spring.—Parula warblers that have wintered in the West Indies reach southern Florida during the first week in March. Dr. Wetmore (1916) says that it "was the most common of the migrant warblers in Porto Rico. * * * Migratory movement was apparent among them by February 14, and after this the birds were very restless, especially during early morning, and there was tendency to work from the east to west. In March and April there were distinct waves of migration.” But it is well on toward the middle of May before the first migrants reach the northern limits of their breeding range.

Professor Cooke’s (1904) records show that the migrants from Mexico and Central America reach the Louisiana coast by the very last of February or early March, while the first arrivals on the lower Rio Grande, in Texas, come two or three weeks later. He observes:

A comparison of the dates shows, first, that the parula warbler arrives in Texas much later than in either of the other States, and hence does not reach the Mississippi Valley by way of Texas; second, that it arrives in northern Florida at least ten days later than it attains the same latitude in Louisiana. From these two facts it would appear that Louisiana is reached by direct flight across the Gulf of Mexico. The average date of arrival at New Orleans coincides closely with the date when the first migrants arrive at the southern end of Florida. It would seem that the birds of Mexico and Cuba are prompted to move northward at the same time, but the flight over the Gulf of Mexico being so much longer than that from Cuba to Florida, the Mexican birds reach a higher latitude by their initial flight.

There are other interesting details in Cooke’s account to which the reader is referred.

During migration the parula warbler does not frequent haunts typical of its breeding ground; in fact such are not to be found in much of the country over which it travels; nor does it especially frequent the coniferous woods to which it is partial in summer. It is to be found almost anywhere, in many kinds of trees, though it seems to show a decided preference for deciduous woods. There, it may often be seen drifting through the highest tree-tops in mixed groups of migrating wood warblers, gleaning insects amidst the freshly opening foliage. Referring to the Buckeye Lake region in Ohio, Milton B. Trautman (1940) writes: “The transient Parula Warblers usually displayed a preference for large pin oak and shingle oak trees and a marked preference for one shingle oak in particular. This oak was in the Lakeside Woods, and more Parula Warblers were observed in it than in all of the remaining trees of the woodland. A transient often displays a marked preference for certain types of trees, but it appears unusual for a single tree among many of the same kind to retain yearly so marked an attraction for a particular bird species.”

The migrating parula warbler is often seen in roadside trees and in shade trees in parks and gardens. It even visits our orchards, where one of the most charming sights of springtime is to see this gay-colored, tiny warbler flitting about in search of insects among the apple blossoms, a delightful bit of color contrast in a beautiful setting.

Nesting.—The nests of the northern parula warbler that we used to find in southern Massachusetts were all located in haunts similar to those described, and mostly in old orchards heavily festooned with beard moss (Usnea). We could usually find three to five nests in a well-populated orchard, but they were so well hidden in the hanging moss that we may have overlooked some. A casual observer would never notice one, but with practice we learned to recognize a rounded, cuplike, thick place in a bunch of Usnea as indicating a nest. The nests were usually made in bunches of moss that hung from horizontal or sloping branches and were from 5 to 15 feet above the ground, more being below than above 12 feet. Some nests were in red cedars, or savins (Juniperus virginiana), scattered among other trees or growing in open stands by themselves; they were located in bunches of Usnea close to the center of the tree and often within reach from the ground. Occasionally, isolated trees on the edges of swamps or on the shores of ponds were sufficiently covered with the lichen to contain nests, and these were sometimes as much as 20 feet above the ground. The nearest approach to a colony that I ever found was in a small cedar swamp, not over an acre in extent, that jutted out from the shore of a lake into rather deep water.

The white cedars (Chamaecyparis thuyoides) were growing in water that was waist deep or more in places, and the whole place was so obstructed with fallen trees and sunken snags that it was very difficult to explore thoroughly; I managed to find some half a dozen nests, and there may have been others, for many of the trees were well “bearded.”

The nests that we have found have all been very simple affairs, apparently merely pockets hollowed out in bunches of hanging Usnea, with side entrances slightly above the cups. Some nests were small and suspended only 2 or 3 inches below the supporting branch, practically open baskets accessible from directly above; others were found in long, thick bunches, a foot or more in length, with long streamers hanging below the nest. External measurements were therefore quite variable. Many of the nests were unlined, save with a soft bed of fine shreds of Usnea, some were scantily lined with a few pieces of fine grass, two or three pine needles, one or two horsehairs, or a few bits of buff-colored down from the stems of ferns; rarely, a nest was more elaborately lined with the latter material but never as profusely as are the nests of other wood warblers.

Apparently the nests were also difficult to find in Connecticut; “J. M. W.” (C. L. Rawson, 1888), who has probably taken more eggs of the blue yellow-backed warbler than any other man, says that the older ornithologists did not realize “that the three Southern New England States were about the centre of its breeding range,” until he began sending eggs to Dr. T. M. Brewer. Thomas Nuttall (1833) remarked: “The nest and eggs are yet unknown.”

Rawson found the parula warbler nesting in colonies near Norwich, Conn., and says:

I know a swamp where may be found seventy-five pairs of these summer residents. The first time I visited the Preston colony on the 31st of May, I took eight sets of four. The first time I visited another large community in this county on June 5, on a point of land trending into salt water, I took eleven sets of four. * * *

The nests are built on dead or green trees, and on savins or deciduous trees, at varying heights. I took one from the single filament of moss caught on the green twig of a birch, within five inches of the ground, and others close to the trunks of great oaks fifty feet in the air. On the lower swamp, huckleberry brush in the littoral colony is a favorite site.

William Brewster (1906) mentions only one nest taken in the neighborhood of Cambridge, Mass., a region where Usnea is scarce:

In shape and general plan of construction the nest closely resembles that of a Baltimore Oriole. It has no hole in the side but instead a wide-mouthed opening at the top through which the bird entered it as the Oriole enters her nest. The upper edges and sides were securely fastened to the fine terminal twigs of a drooping branch where the nest hung suspended among the evergreen foliage of the hemlock, precisely as the Oriole’s hammock swings in the dropping spray of an elm. The Warbler’s nest has a scanty lining of pine needles and fine grasses but it is otherwise composed entirely of Usnea, loosely woven or perhaps merely felted together, evidently by the parent birds. They must have been at some pains to collect this material, for the closest scrutiny on the part of a friend and myself failed to reveal more than a few small and scattered tufts of Usnea in the surrounding woods.

Henry Mousley (1924, 1926, and 1928), of Hatley, Quebec, made three attempts to make complete studies of the home life of the northern parula warbler, none of which covered the whole cycle for reasons beyond his control.

The nests were suspended from the branches of coniferous trees, at heights ranging from 26 feet in a spruce to 40 feet in a balsam fir. One of these nests was watched for a total of 24 hours, from May 22 to 31, during the process of construction; during this time the male sang 549 times from a little birch and went with the female to the nest, but brought no material; the female, however, made 206 trips with material, an average of one load every 5.4 minutes. The nest was made entirely of Usnea, all brought in, and lined with “some black hair-like rootlets, with two bits of plant down”; it was strengthened with a few fine grass stems. It weighed only 100 grains, or .23 ounce! “Outside diameter 3.25, inside 1.75 inches; outside depth 2.50, inside 1.75 inches. The female after selecting some of the longest threads of the hanging bunch of Usnea, attached them to a little twig a few inches off, following this up with that curious process—inherent—of moulding the nest, which in this case, was really an acrobatic performance, there being of course no apparent nest to mould, just a few strands, through which the bird’s tail and wings protruded.”

Outside New England, where Usnea is scarce, the nests are often built in hanging clusters of twigs of hemlocks or spruces, with the use of more or less of this lichen when available. In the lower Mississippi Valley, Spanish moss (Tillandsia usneoides) offers a popular substitute and is generally found growing in profusion. But some nests are built of various other materials. George H. Stuart, 3d, writes to me of a nest he found at Pocono Lake, Pa., on June 22, 1916: “This remarkable nest was placed in a horizontal limb of a spruce, 20 feet up and 12 feet from the trunk, near the tip and overhanging a road near the lake.” It was “composed mainly of fine dry grasses and the thinnest of bark shreds, with a few bits of down, fashioned together oriole-like, though loosely, with a few coarse grasses projecting suggesting the handiwork of the magnolia warbler. The tiny basket was suspended from the under side of the branch, partially supported by inclining twigs. In form it is an inverted cone or pear, measuring 3 inches deep by 3 inches wide at the rim, the thin walls tapering down to a narrow, pointed bottom. The thinness of the walls in places revealed the eggs from a side view.”

Mrs. Nice (1931) reports a curious nest, found by Mr. Kirn near Copan, Okla.; it was fastened to ivy leaves and to a stick which was hanging down, held by the vine. “In this hanging, swaying cluster about two feet long, the nest was built almost entirely of box elder blossoms held together by spider webs on the outside, and sycamore seed down on the inside with a light lining of fine strips of weed stems.”

Several nests have been reported as built of various materials in bunches of leaves and other rubbish deposited by freshlets on branches over streams.

Because of the bird’s habit of using various materials and sites in its nest building, it may be well to mention some nesting records from the southern Gulf States. Andrew Allison wrote to Dr. Chapman (1907):

The invariable nesting site is a clump of Spanish moss—where this it to be had; I have not observed nests from beyond the range of this plant. The nest is generally placed near the branch from which the long filaments of the ‘moss’ depend, so that it is well concealed. The height from the ground varies from about eight feet upwards. * * * The nest is nearly hemispherical in shape, opening directly upward. The usual material, in lower Louisiana, is thistle down, which is abundant during the nesting season. Animal hairs are not used, I think. A nest from Bay St. Louis was composed of the very black horse-hair-like inner fiber resulting from the decay of Tillandsia.

M. G. Vaiden writes to me that he found a nest near Belzoni, Miss., in a heavy oak swamp where there were clusters of Usnea on practically all of the trees. The nest was 16 feet above the ground and 12 feet out on a limb of an oak; it was made like our northern nests and lined with the “moss” and fine rootlets. Another described in his notes was entirely different. It was in a section of Mississippi where there was no Usnea growing within 60 miles. The nest was 6 feet from the ground and 4 feet out in the crotch of a limb of a hackberry tree. A pretty nest, it was nicely constructed of leaves and bark from cypress trees, and was lined with small rootlets and very fine twigs.

Eggs.—The usual set for the northern parula warbler consists of 4 or 5 eggs; 3 sometimes constitute a full set, and as many as 6 or 7 have been found in a nest; there are 3 sets of 7 in the J. P. Norris collection. The eggs are ovate or short ovate, have only a slight gloss, and are white or creamy white, speckled and spotted with shades of “russet,” “chestnut,” “bay,” and “auburn,” with a few underlying spots of “brownish drab.” There is much variation; on some eggs the “brownish drab” color is entirely lacking, while on others spots of this color are the most prominent markings; again, the eggs may be almost immaculate, or may have just a few indistinct freckles of “pale wood brown” at the large end. The measurements of 50 eggs average 16.5 by 12.1 millimeters; the eggs showing the four extremes measure 18.3 by 12.7, 16.9 by 12.9, 14.8 by 11.9, and 16.3 by 11.2 millimeters (Harris).

Young.—The period of incubation does not seem to have been determined, nor do we know how long the young remain in the nest. Incubation of the eggs and brooding of the young is performed mainly by the female, but the male assists in both to some extent. I have seen a male leave a nest in which there were eggs; and Mr. Mousley (1924) saw a male brood the young for a period of 4 minutes in the absence of the female, but he left as soon as she returned. Both parents feed the young. Mr. Mousley’s table shows that during a watching period of 15 hours the male fed the young 45 times and the female fed them only 21 times; the average rate of feeding was once in 13.6 minutes; during this time the male brooded once and the female 34 times, a total of 11 hours and 27 minutes. He “noticed that the food the male brought consisted almost invariably of soft green larvae, whereas, that of the female more often than not consisted of insects, and the portions she brought were usually smaller in proportion than those of her partner.”

Plumages.—Dr. Dwight (1900) says that the natal down is “smoke-gray.” The sexes are alike in the juvenal plumage, which Ridgway (1902) describes as “above plain slate-gray, slightly tinged with olive-green; middle and greater wing-coverts narrowly tipped with white; chin and upper throat pale yellowish; lower throat, chest, sides, and flanks plain light gray (intermediate between mouse gray and gray no. 6); abdomen, anal region, and under tail-coverts white; remiges and rectrices as in adults.”

A postjuvenal molt, involving all the contour plumage and the wing coverts but not the rest of the wings or the tail, begins about the middle of July. This produces a first winter plumage in which old and young birds are very much alike and the sexes are recognizable. The young male differs little from the adult male, but the bluish gray of the upper parts is more heavily tinged with olive-green, the yellow of the under parts is duller, and the dark throat band is more or less obscured by yellowish tips on the feathers. The young female differs from the adult female in a similar way and is without any brown throat band.

Dr. Dwight (1900) says that the first nuptial plumage is “acquired by a partial prenuptial moult which involves chiefly the head, chin and throat, but not the rest of the body plumage, the wings nor the tail. The ashy blue crown feathers faintly dusky centrally, the blackish ones of the sides of the head with a white spot above and below the eye and the yellow or chestnut-tinged chin feathers as far as the pectoral band or farther are assumed by moult. Wear brings the back into contrast with the nape and whitens the lower parts. The wings and tail are browner and more worn than in the adult, especially the primary coverts.”

A first postnuptial molt in July and early August, which is complete, produces the fully adult plumage. Fall males are similar to spring males, but the blue areas are more or less tipped with greenish and the throat bands with yellowish. Fall females differ in the same way from the spring birds, and there is little, if any, chestnut and no blackish in the throat band.

Subsequent molts and plumages are the same as described above for the young birds.

Charles C. Ayres, Jr., writes to me of a bird he observed near Ottumwa, Iowa: “It was a typical parula warbler with the exception that the blue-gray color extended over the throat and terminated abruptly on the upper breast. Immediately below the termination of the blue-gray color was the well-defined orange-brown breast band, below which the rest of the breast was yellow.”

Food.—The parula warbler is almost wholly insectivorous. Its food is mainly obtained in the deciduous trees, where it is often seen among the branches and twigs or hanging downward under a cluster of leaves or blossoms like a chickadee searching for small insects, beetles, flies, moths, larvae, and egg clusters. Some flying insects are taken on the wing; and occasionally the bird may be seen feeding on the ground.

Dr. Wetmore (1916) reports on the contents of 61 stomachs from Porto Rico, which contained 97.7 percent animal matter and only 2.3 percent vegetable matter. The latter “consisted of seeds of small berries of the camacey (Miconia prasina) and others.” In the animal food, beneficial insects and a large number of spiders amounted to about 35 percent, and the remainder were all harmful pests. “Lantern flies (Fulgoridae) (19.09 percent) were identified in 29 stomachs. * * * Other bugs (3.69 percent) comprise small numbers of leaf bugs, species of the chinch bug family, stink-bugs, and a few predaceous assassin bugs. The birds are fond of beetles, and this order supplies 22.53 percent of the food, nearly all being injurious species. Ladybird beetles (1.36 percent) were present in 14 stomachs. Longicorn beetles (1.68 percent) were taken 11 times, and leaf beetles of several species (7.95 percent) were eaten by 30 of these birds.” Other beetles taken included darkling beetles, skin beetles, scarred-snout weevils, coffee leaf-weevils, stalk borers, and curculios. Among other items were a few ants and other small Hymenoptera (3.57 percent) and flies (1.19 percent). Caterpillars were found in 18 stomachs and moths in 4. Spiders (29.53 percent) were identified in 29 stomachs. Stuart T. Danforth (1925), from Puerto Rico, adds berries of Varronia angustifolia and fleabeetles, and says that large moth eggs were eaten by two birds, forming 25 percent of their food. Forbush (1929) says that “it feeds much on small hairless inch-worms, such as the fall canker-worm and the spring canker-worm, and on the younger and smaller hairy caterpillars, such as the gipsy and the tent caterpillar.”

Behavior.—The parula warbler is less active in its movements, more sedate and deliberate, than most of the other tree-top wood warblers.

It creeps along the branches and hops from twig to twig, often clinging to the under side of a cluster like a chickadee, an action that led some of the early writers to refer to it as a small titmouse, and it sometimes clings to the trunk of a tree like a nuthatch in its search for food. The birds are fearless and confiding, and are easily approached. Even when their nest is disturbed they come within a few feet of the intruder, making little, if any, protest or demonstration. George B. Sennett (1878) tells the following story, illustrating the confiding nature of the bird:

Just before we sighted land, imagine our surprise and joy to see a little Blue Yellow-backed Warbler on our mast. It soon flew down to the sail and thence to the deck, where, after a few moments, it felt quite at home. Our sailor caught him, and he was passed around for all to admire and pet. It would nestle in our hands and enjoy the warmth without the least fear. When allowed his freedom, he would hop upon us, fly from one to another, and dart off over the side of the boat as if taking his departure; when lo! back he would come with a fly or moth he had seen over the water and had captured. Several flies were caught in this way. He searched over the whole boat and into the hold for insects. Often he would fly to one or the other of us, as we were lying on the deck, and into our hands and faces, with the utmost familiarity. He received our undivided attention, but could have been no happier than we. Upon reaching shore, amid the confusion of landing we lost sight forever of our pretty friend.

Voice.—The parula warbler has a simple, but to my ears a very distinctive, song. In 1900 I recorded the song in my notes as “pree-e-e-e-e-e-e, yip, a somewhat prolonged trill like a pine warbler’s, but fainter and more insect-like, ending abruptly in the short yip with a decided emphasis.” I have always been able to recognize it by the explosive ending, which I never heard from any other wood warbler.

Gerald Thayer wrote to Dr. Chapman (1907) as follows:

The Parula is weak-voiced, and its call notes, as far as I know, are slight and barely peculiar; but it has at least three main songs, with great range of variations.

All may be recognized, or at least distinguished from the weak songs of the Dendroicae, like the Blackburnian and Bay-breast, by their beady, buzzy tones. In phrasing, in everything but tone-quality, certain variations of the Parula’s and of the Blackburnian’s songs very nearly meet and overlap; but the tell-tale tones remain unchanged,—wheezy and beady in the one, smooth as glass in the other. Commonest of the Northern Parula’s three main songs is probably the short, unbroken buzz, uttered on an evenly-ascending scale, and ending abruptly, with a slight accentuation of the final note. Next is that which begins with several notes of the same beady character, but clearly separated, and finishes, likewise on an ascending scale, with a brief congested buzz. The third main song is based on an inversion of the second—a buzz followed by a few separate drawled notes, high-pitched like the buzz-ending of the two other songs. All these vary and intervary perplexingly.

Aretas A. Saunders contributes the following notes on the song of this warbler: “The parula warbler has two distinct types of song. One is a simple buzzy trill rising in pitch, and frequently terminated by a short, sharp note of lower pitch. Of 12 records of this song, 7 have the terminal note and 5 do not. The other form has the same buzz-like quality, but begins with three or four short notes on the same pitch, followed by a longer, higher note that is frequently, but not always, slurred upward. Both songs are similar in length and in pitch intervals. They vary from 1¹⁄₅ to 1³⁄₅ seconds in length. The rise in pitch varies from one to four and a half tones, and averages about two tones. The actual pitch is exceedingly variable in individuals and varies from A‴ to D‴″. Songs vary considerably in loudness, many of them becoming suddenly louder toward the end.

“The species sings throughout migration, and on the breeding grounds till late July. At that season I have seen males still singing while feeding young just out of the nest.”

Enemies.—Dr. Friedmann (1929) writes; “This bird is practically free from that greatest enemy of most of the warblers, the Cowbird. Occasionally, however, parasitic eggs are found in the dainty pensile nests of the Parula Warbler. Stone found a nest on May 26, 1892, at Cape May Point, New Jersey, containing three eggs of the Warbler and one of the Cowbird. * * * Five other records have come to my notice, from Long Island, New York, Pennsylvania and Connecticut, and the bird is listed as a victim of the Cowbird by several writers, as Bendire, Davie, and Chapman.” Mrs. Nice (1931) records two more cases in Oklahoma.

Harold S. Peters (1936) records two lice, Myrsidea incerta (Kellogg) and Ricinius sp., as external parasites on this species.

Field marks.—The parula, is one of our smallest warblers. The adult male is well marked, with its blue upper parts, the yellow back being inconspicuous, two conspicuous white wing bands, black lores, yellow breast and chestnut or blackish throat band. The female is duller in all colors, more greenish above and has little or no throat band. Young birds are even less conspicuously marked, as noted in the description of plumages.

Fall.—As soon as the young are strong on the wing the family parties desert their breeding grounds, and after the molting season is finished they resort to the deciduous woods and join the migrating hosts of warblers and other small birds drifting southward through the tree-tops or along the roadside shade trees. The fall migration is apparently a reversal of the springtime routes, as they travel to their winter haunts in Mexico and the West Indies. Professor Cooke (1904) says that this warbler “passes through Florida in countless thousands, being second only to the black-throated blue warbler in the frequency with which it strikes the lighthouses. * * * By the middle of September the great flights begin and continue in full force for a month.”

DISTRIBUTION

Range.—Southern Canada to Nicaragua and the West Indies.

Breeding range.—The Parula warbler breeds north to southern Manitoba (Shoal Lake and Caddy Lake); central Ontario (Off Lake, Rossport, and Lake Abitibi); and southern Quebec (Lake Timiskaming, Blue Sea Lake, Gaspé Peninsula, and Anticosti Island). East to Anticosti Island (Fox Bay); Prince Edward Island (Tignish); Nova Scotia (Halifax and Yarmouth); and the Atlantic coast south to central Florida (Deer Park, Lake Gentry, and St. Lucie). South to central Florida (St. Lucie, Bull Creek Swamp, and Tarpon Springs) and the Gulf coast to south-central Texas (Houston and San Antonio). West to central Texas (San Antonio and Kerrville); eastern Oklahoma (Caddo, red Oak, and Copan); eastern Kansas (Neosha Falls, Topeka, and Leavenworth); central Iowa (Des Moines); north-central Minnesota (Cass Lake and Itasca); and southeastern Manitoba (Shoal Lake).

Winter range.—The parula warbler winters north to southern Tamaulipas (Tampico); occasionally southern Florida (Tarpon Springs, Sanibel Island, and Miami); the Bahamas Islands (Nassau and Caicos); Hispaniola (Tortue Island and Samaná); Puerto Rico; the Virgin Islands (St. Thomas); and the Lesser Antilles (Saba). East to the Lesser Antilles (Saba, St. Christopher, Guadaloupe, and Barbados). South to the Lesser Antilles (Barbados); Jamaica (Kingston); and Nicaragua (Río Escondido). West to Nicaragua (Río Escondido); El Salvador (Barra de Santiago); western Guatemala (San José and Escuintla); southern Oaxaca (Tehuantepec); Veracruz (Tlacotalpan); and Tamaulipas (Tampico).

The above range is for the species as a whole, of which two geographic races are recognized: the southern parula warbler (P. a. americana) breeds in southeastern United States from Maryland southward, east of the mountains; the northern parula warbler (P. a. pusilla) breeds in the western and northern portion of the range.

Migration.—Late dates of spring departure from the winter home are: El Salvador—Barra de Santiago, April 18. Guatemala—San José, March 7. Yucatán—San Felipe, April 4. Virgin Islands—St. Croix, April 30. Puerto Rico—Mayagüez, May 7. Haiti—Port au Prince, April 4. Cuba—Habana, May 4. Bahamas—Cay Lobos, May 14.

Early dates of spring arrival are: Florida—Daytona Beach, March 3. Alabama—Coosada, March 25. Georgia—Savannah, March 8. South Carolina—Frogmore, March 5. North Carolina—Washington, March 26. West Virginia—Bluefield, April 9. District of Columbia—Washington, April 6. Pennsylvania—Carlisle, April 25. New York—Shelter Island, April 23. Massachusetts—Stoughton, April 25. Vermont—St. Johnsbury, April 21. Maine—Portland, April 29. Nova Scotia—Wolfville, May 8. New Brunswick—St. Stephen, May 9. Quebec—Quebec, May 10. Louisiana—New Orleans, February 15. Mississippi—Bay St. Louis, March 5. Arkansas—Helena, March 24. Tennessee—Athens, April 3. Kentucky—Eubank, April 4. Indiana—Bloomington, April 21. Ohio—Columbus, April 28. Michigan—Ann Arbor, April 29. Ontario—Toronto, May 2. Missouri—Columbia, April 5. Iowa—Grinnell, April 28. Wisconsin—Madison, April 30. Minnesota—Red Wing, May 5. Texas—Hidalgo, March 5. Oklahoma—Caddo, March 25. Kansas—Independence, April 8. Nebraska—Havelock, April 20.

Late dates of fall departure are: Minnesota—St. Paul, October 5. Wisconsin—Milwaukee, October 9. Missouri—St. Louis, October 5. Ontario—Point Pelee, October 5. Michigan—Grand Rapids, October 19. Ohio—Toledo, October 19. Indiana—Richmond, October 14. Tennessee—Nashville, October 3. Arkansas—Monticello, October 2. Louisiana—Covington, October 26. Mississippi—Gulfport, November 2. Quebec—Hatley, September 30. New Brunswick—Scotch Lake, September 28. Maine—Portland, October 24. New Hampshire—Hanover, October 11. Massachusetts—Rockport, October 25. New York—Rhinebeck, October 21. Pennsylvania—Berwyn, October 26. District of Columbia, Washington, October 17. West Virginia—French Creek, October 1. Virginia—Lynchburg, October 17. North Carolina—Rocky Mount, October 23. South Carolina—Charleston, October 22. Georgia—Athens, November 4. Florida—Gainesville, November 19.

Early dates of fall arrival are: Bahamas—Watling Island, September 28. Cuba—Habana, August 10. Dominican Republic—San Juan, October 21. Puerto Rico—Parguera, September 19. Nicaragua—Río Escondido, October 20. Costa Rica—Villa Quesada, October 24.

Banding.—Only a single migration record is available from banded birds. A parula warbler banded as an adult at Flushing, Long Island, New York, on September 16, 1946, was found dead about October 1, 1947, at La Grange, Maine.

Casual records.—The parula warbler has been recorded three times in Colorado (in El Paso County, at Kit Carson, and at Denver); and three times in Wyoming (once at Cheyenne and twice at Torrington).

Egg dates.—Massachusetts: 52 records, May 20 to July 7; 29 records, May 29 to June 10, indicating the height of the season.

Connecticut: 39 records, May 25 to June 25; 25 records, June 1 to 10.

South Carolina: 20 records, April 10 to June 24; 10 records, April 30 to May 11.

PARULA AMERICANA AMERICANA (Linnaeus)

SOUTHERN PARULA WARBLER

Plate 22

HABITS

This southern race of our well-known blue yellow-backed warbler is said to breed from the District of Columbia southward to Florida and Alabama. William Brewster (1896), in describing and naming the northern race, restricted the Linnaean name americana to the southern bird because it was evidently based on Catesby’s excellent plate, drawn from a bird taken in South Carolina. In his comparative diagnoses of the two forms, he describes the southern bird as "averaging slightly smaller but with longer bill. Adult male with more yellow on the under parts and less black or blackish on the lores and malar region; the dark collar across the jugulum narrow, obscure, often nearly wanting; the chest pale, diffuse russet, without obvious markings.” He admits that no one of these characters is quite constant, the best one being the depth and definition of the reddish brown on the chest. And he suggests that the distribution of the two forms in the breeding season may be roughly correlated with the distribution of Usnea in the north and of Tillandsia in the south, in which the two forms, respectively, seem to prefer to build their nests. This, however, is not strictly accurate or universal (for example, see some remarks by M. G. Vaiden, under the preceding form, on the breeding of this species in two different localities in Mississippi).

Arthur T. Wayne (1910) says of the haunts of the southern bird in South Carolina: “As soon as the sweet gum trees begin to bud, the song of this beautiful bird is heard. It heralds the approach of spring and is one of the first warblers to arrive which does not winter. The range of this species in the breeding season is entirely governed by the presence or absence of the Spanish moss, and where the moss is growing in profusion the birds are common, but where the moss is absent the birds are absolutely not to be found.”

A. H. Howell (1932) calls this southern subspecies “an abundant spring and fall migrant [in Florida]; a common summer resident south at least to Osceola County; and a rare winter resident, chiefly in the central and southern part. Owing to the presence of a few wintering individuals, it is difficult to determine when spring migration begins. * * * Positive evidence of migration is furnished by the appearance of large numbers striking the light on Sombrero Key, March 3, 1889, when 250 birds were observed and 30 were killed. This species is one of the most numerous and regular visitants at the lighthouses on the east coast and on the Keys.” Many of these were, of course, the northern race. Of the haunts of the southern race, he says: “The dainty little Parula Warbler is found most frequently in cypress swamps or heavily timbered bottom-lands, and to a lesser extent in the upland hammocks. The abundant Spanish moss on the trees furnishes ideal nesting sites for the birds.”

Nesting.—Except for the fact that the so-called Spanish moss (Tillandsia) replaces the beard moss (Usnea), the nesting habits of the two races are very much alike. A. T. Wayne (1910) says that in South Carolina “the nest is always built in the festoons of the Spanish moss, from eight to more than one hundred feet from the ground, and is constructed of the flower of the moss and a few pieces of fine, dry grass.” The nesting habits in Florida are very similar.

In southeastern Virginia, according to Harold H. Bailey (1913) this southern race is:—

a most common breeding bird in its favorite haunts, the cypress or juniper swamps of the southeastern section; Cape Henry southward. These trees seem to furnish particularly fine feeding grounds, and wherever you find one festooned with the long, hanging Spanish moss, here also you are likely to find one or more nests. In this section I should call them a colony bird, for in days past I have seen on the trees in and surrounding one small lake, as many as two hundred pair breeding in company. The Dismal Swamp and its surrounding low territory has been an ideal spot for a feeding and breeding home in years past, but of late, the cutting of the juniper for commercial purposes, and the disappearance of the moss to a great extent, has driven the majority of the birds elsewhere.

Eggs.—These are indistinguishable from those of the northern parula warbler. The measurements of 50 eggs average 16.2 by 12.0 millimeters; the eggs showing the four extremes measure 19.5 by 12.7 and 14.0 by 11.0 millimeters (Harris).

Food.—Howell (1932) reports: “Examination of the stomachs of four birds taken in Florida in February showed the contents to consist almost wholly of insects and spiders, with a few bud scales. Hymenoptera (ants, bees and wasps) composed the largest item, amounting in two instances to approximately half the total contents. Other insects taken in smaller quantities were lepidopterous larvae, fly larvae, beetles, weevils, scale insects, bugs, and grouse locusts. Spiders were found in three stomachs, and amounted to about 20 per cent of the total food.”

PARULA PITIAYUMI NIGRILORA (Coues)

SENNETT’S OLIVE-BACKED WARBLER

HABITS

This northern race of a wide-ranging species is represented by a number of allied races in Central and South America. From its range in northeastern Mexico it rarely crosses our border into the valley of the lower Rio Grande in southeastern Texas. For its introduction into our fauna and for most of our knowledge of its habits we are indebted to George B. Sennett (1878 and 1879) and to Dr. James C. Merrill (1878). The discovery of the bird in Texas in 1877 is thus described by Mr. Sennett:

On April 20th, soon after reaching Hidalgo, I was directed up the river some four miles by road, and there shot the first three specimens of this new species. On May 3d, another was shot among the mesquite timber of the old resaca, within a mile of town.

On May 8th, another was shot in a dense forest about half a mile from where the first three were obtained. Several more were seen; in fact, they were more abundant than any other Warbler. * * * All of the specimens obtained are males, and I remember of seeing none in pairs. They were seen usually in little groups of three or four. They are by no means shy, but frequenting, as they do, the woods, cannot be readily seen.

He visited the locality again the following year and says in his report (1879):

It is truly a bird of the forest, and delights to be in the upper branches of the tallest trees. The song of the male is almost continuous as it flies about, and is so clear that it can be heard at a long distance and readily distinguished from all other birds. By its notes we could locate the bird, and this accounts for our securing so many more males than females. Were it not for its song, I doubt if we would have taken many, owing to their diminutive size and habit of frequenting the tops of the forest-trees. As it was, by only taking such as came in our way, we shot over twenty specimens, and could have taken any number more had we set out for them alone. In feeding habits I could see nothing different from our familiar Blue Yellow-back, P. americana.

Dr. Merrill (1878) says of its haunts: “Arrives about the third week in March, and passes the summer among thick woods and near the edges of lagoons where there is Spanish moss.” We found Sennett’s warbler fairly common around Brownsville, especially on the edges of the resacas, partially dry old river beds where the trees, mostly small mesquites, are more or less draped with Usnea and suggest the places where we would look for parula warblers in the north.

In appearance and behavior they were strikingly reminiscent of our northern friends. Sutton and Pettingill (1942) found this warbler up to 2,000 feet elevation in southwestern Tamaulipas, in full song on March 14, and a pair copulating on March 20.

Nesting.—Dr. Merrill sent to Mr. Sennett (1878) the following description of a nest he found near Brownsville after Mr. Sennett left: “My nest of Parula was taken July 5th, about five miles from here. It was placed in a small thin bunch of hanging moss, about ten feet from the ground, in a thicket; was simply hollowed out of the moss, of which it was entirely composed, with the exception of three or four horsehairs; entrance on side; contained three young about half fledged. Parents very bold, but thinking they were americana I did not shoot them.”

The next year, his Mexican guide brought him a nest and a broken egg, which Mr. Sennett (1879) describes as follows:

The nest is exceedingly interesting and beautiful. It is made in a gray mistletoe-like orchid, an air-plant very common on the Rio Grande, which establishes itself on the small branches of trees, and varies in size up to eight or ten inches in diameter. This one is six inches long by four and one-half inches wide, quite firm in texture, and was fastened some ten feet from the ground, to the end of a drooping branch of a brazil-tree in open woodland. The nest is constructed very simply, being formed by parting the gray leaves of the orchid and digging into its centre from the side, a cavity some two inches in diameter being made, with an opening of one and one-quarter inches. The bottom and sides are lined pretty well up with short cotton wood fibres, forming a fine matting for the eggs to rest upon. A firmer and more secure nest is seldom seen, although so easily made. I imagine a day would complete one, and certainly but little time need be wasted in selecting a site, for thousands of orchids stand out on the partially dead branches on trees with little foliage. That they build also in the hanging trusses of Spanish moss, so abundant everywhere, is true, the young before referred to being found in a nest in one.

There are two nests of Sennett’s warbler in the Thayer collection in Cambridge. One of these was taken for F. B. Armstrong in Tamaulipas, Mexico, on July 5, 1911, and held three eggs. It is described as a “nest of hair in bunch of growing moss hanging from limb of cypress tree in river bottom,” 8 feet up; it is built right into the Tillandsia and is made almost wholly of black and white cattle hair. The other, with a set of four eggs, was taken by James Johnson near Saltillo, Mexico, on May 27, 1906. It is described by the collector as “dug and hollowed in a bunch of pipestem mosses.” It is a compact little nest made of very fine rootlets, very fine grasses, shreds of the brown inner bark of the palmetto or palm, and some weed blossoms; it is lined with finer shreds, a little plant down, and a few feathers. Externally it measures 2¹⁄₂ inches in diameter and 2 inches in height; the inside diameter is about 1¹⁄₂ inches; and the depth of the cup about 1¹⁄₄ inches.

Eggs.—Either 3 or 4 eggs seem to constitute the full set, as far as we now know, for Sennett’s warbler. The 7 eggs in the Thayer collection vary from ovate to short ovate, and have only a slight lustre. They are white or creamy white and are speckled and spotted with shades of “wood brown,” “cinnamon-brown,” or “Brussels brown,” with underlying spots of “pale brownish drab.” On some eggs the markings run to much darker browns, such as “auburn” and “chestnut,” and on these the drab spottings are frequently lacking. Usually a loose wreath is formed where the spots are concentrated at the large end, but occasionally they are distributed nearly evenly over the entire surface. The measurements of 36 eggs average 16.3 by 12.2 millimeters; the eggs showing the four extremes measure 19.0 by 13.7 and 15.0 by 11.3 millimeters (Harris).

Plumages.—Young Sennett’s warblers that I have examined are uniform grayish olive above, inclining to olive-green on the back; the black lores and cheeks are lacking; the median wing coverts are narrowly tipped with whitish, and the greater coverts more broadly so; the chin is pale yellow; the chest and upper breast are shaded with pale gray and centrally tinged yellowish; the abdomen is dull white; and the sides and flanks are shaded with pale olive-grayish. I have not seen enough material to trace subsequent molts and plumages, which doubtless parallel those of the parula warbler.

Food.—We have no definite information about the food of Sennett’s warbler, but Clarence F. Smith has sent me the following note: “The only laboratory report available on the food of the species pertains specifically to a South American subspecies of the pitiayumi group. The stomach contents were reported to consist of remains of hymenopterous insects and two-winged flies (Zotta, 1932).”

* * *

Nothing further seems to have appeared in print regarding the habits of this warbler. It is much like the well-known parula warbler in appearance and behavior, but can be recognized in the field by the conspicuous black lores and cheeks and by the complete absence of any pectoral band.

DISTRIBUTION

Range.—The species ranges from southern Texas to northern Argentina and Uruguay. The race occurring in the United States is found in southern Texas and northeastern Mexico.

Breeding range.—Sennett’s olive-backed warbler breeds north to northeastern Coahuila (Sabinas); and southern Texas (Hidalgo, Harlingen, and Point Isabel). East to southern Texas (Point Isabel and Brownsville); and southeastern Tamaulipas (Altamira and Tampico). South to southern Tamaulipas (Tampico); and southern San Luis Potosí (Valles). West to eastern San Luis Potosí (Valles); and eastern Coahuila (Cerro de la Silla and Sabinas).

Winter range.—While probably not a sedentary form, its winter range very nearly coincides with its breeding range. It has been found in winter from Brownsville, Tex., to northern Hidalgo (Jacala).

Egg dates.—Texas: 6 records, April 28 to May 30; 4 records, May 2 to 12, indicating the height of the season.

Mexico: 2 records, May 27 and July 5.

PARULA GRAYSONI Ridgway

SOCORRO WARBLER

HABITS

The Socorro warbler is closely related to Sennett’s warbler and other races of pitiayumi but is accepted as a distinct species. It differs from nigrilora in having gray, instead of black, lores and cheeks, and in having much less white on the inner webs of the outer rectrices. It was supposed to be confined to Socorro Island, one of the Revillagigedo group, about 250 miles southwest of the southern tip of Baja California. It was added to our fauna by Chester C. Lamb (1925), who states:

On November 3, 1923, I collected one of these birds at Todos Santos, on the Pacific Ocean side of the peninsula of Lower California, some forty miles north of Cape San Lucas. * * * On February 5, 1924, I saw another of these little warblers, within a few feet of me; but my gun was not at hand, so I had to be content with a sight record. The locality was inland, at El Oro, on the east side of the Victoria Mountains, about thirty miles from Todos Santos. The next occurrence, like the first, was at Todos Santos, where, on July 23, 1924, I secured an adult female which is now in my collection at the Los Angeles County Museum, Los Angeles. The taking of these two birds, in the winter and summer of two successive years, would indicate that the species is of more or less regular occurrence in the Cape Region of Lower California. The capture of a specimen in July suggests the possibility of breeding at the point of record.

Nothing more seems to have been heard of the species since. And we know nothing of its habits.

DISTRIBUTION

Range.—Socorro Island and the Cape region of Baja California.

Breeding range.—The Socorro warbler is known to breed only on Socorro Island, where it is resident. It has been found in the breeding season near Todos Santos, Baja California.

This warbler has been found in winter in two localities (Todos Santos and El Oro) in Baja California, and appears to be resident in small numbers.

PEUCEDRAMUS TAENIATUS ARIZONAE Miller and Griscom

NORTHERN OLIVE WARBLER

Plate 23

HABITS

The olive warbler was long classed as a species of Dendroica, with Peucedramus regarded as a subgenus, but it is now properly placed in a genus by itself, for as Dr. Chapman (1907) points out it differs from Dendroica chiefly “in its slenderer, more rounded bill, proportionately longer wings (about 1.00 inch longer than the tail) and decidedly forked tail, the central tail feathers being more than .25 inches shorter than the other ones. In general color and pattern of coloration Peucedramus is markedly unlike Dendroica, from all the species of which the male differs in requiring two years to acquire adult plumage.”

For a still longer time it was supposed to be a homogeneous species, until Miller and Griscom (1925) made a study of it and divided the species into five subspecies, mostly Mexican and Central American. In giving this bird the name P. t. arizonae, they state that it is entirely different in coloration from the type race; "upperparts plain mouse-gray, in spring plumage almost never tinged with olivaceous, even on the upper tail-coverts, appearing lighter and grayer than typical olivaceus; collar on hind neck not so complete, usually invading the occiput; primaries rarely if ever edged with olive-green in spring plumage; head and throat plain ochraceous, duller than in typical olivaceus; underparts lighter, the center of the belly purer white, more contrasted with the flanks, which are less olivaceous, more grayish brown; size as in typical olivaceus. Throat and side of neck of adult female and immature pale lemon-yellow.” They give as its range “mountains of southern and central Arizona south at least to Chihuahua and perhaps east to western Tamaulipas (Miquihuana).”

The species had long been known in Mexico and had been erroneously reported in Texas, but it remained for Henry W. Henshaw (1875) to record it definitely as a North American bird by capturing three specimens on Mount Graham, Ariz., in September, 1874. Since then it has been noted by numerous observers on several other mountain ranges in southern Arizona, where it is now known to be fairly common in summer and where a few remain in winter.

It is a bird of the open pine forests on or near the summits of the mountains. In the Huachucas we found it breeding at about 9,000 feet elevation in the open forests of yellow pine, sugar pine, and fir. As Swarth (1904) says: “I found them only in the pine forests of the highest parts of the mountains, even in cold weather none being seen below 8,500 feet; and more were secured above 9,000 feet than below it.”

In the Chiricahuas, Frank Stephens collected a fine series of these warblers for William Brewster (1882a) in March, 1880, in the pine woods at elevations from 10,000 to 12,000 feet. And it was here that W. W. Price (1895) found the first nest in 1894; “the region was a dry open park, thinly set with young pine (Pinus jeffreyi), at between nine and ten thousand feet above the sea.”

The olive warbler is not always confined to the pines at all seasons, for Dr. Walter P. Taylor tells me that he obtained a single specimen from an oak tree in the Santa Rita Mountains at 5,000 feet on February 4, 1923. It was in the same general locality with bridled titmice and ruby-crowned kinglets, and was alone, perhaps a winter wanderer, foraging nervously through the foliage of the oak.

Spring.—According to Swarth (1904), migrating olive warblers reach the Huachuca Mountains, from their winter resorts in northern Mexico, about the first of April. “In 1903 they became fairly abundant, particularly in April, when many small flocks of five or six birds each, were seen. * * * They were seldom in company with other warblers, but when not alone, associated with nuthatches and creepers.” Frank C. Willard (1910) says that "the first few days are spent, as it were, in staking out their claims anew. The males at this time are quite pugnacious toward one another, and, tho apparently already mated, they promptly drive any wanderer of the same sex from their selected bit of forest. I believe they return each year to the same locality in which they made their home of the previous year, as I have found them in the same patch of trees year after year while other places near by, with the same apparent advantages, never seem to be chosen.” Dr. Taylor (MS.) saw a pair of olive warblers, 20 to 30 feet up in some yellow pines in the Santa Catalina Mountains on May 13, 1928. They kept giving a whistled call with descending inflection. “The two birds were courting apparently, flying about, often facing each other at short range, 6 to 18 inches, calling at very frequent intervals.”

Nesting.—To William W. Price (1895) belongs the honor of finding the first nest of the Arizona olive warbler. On June 15, 1894, on the Chiricahua Mountains, he—

saw a female, closely followed by a male, fly from a bush of spirea (Spirea discolor) to the top of a small pine, and busy itself on a small horizontal limb partially concealed by pine needles. She soon returned to the spirea, followed by the male, which did not enter the bush but perched on a pine branch near by. The female again flew with a dry flower-stem in her bill, from the bush directly to the pine, where a nest was in process of construction. * * * A few days after, a forest fire drove me from my camp, and it was not until July 1 that I was able to visit the nest. The female was sitting, and when frightened from the nest, kept hovering about, but made no sound. The male did not appear at all. The nest was compactly built and placed on a small horizontal branch, about forty feet from the ground, and about six feet from the top of the tree. The eggs, four in number, were in an advanced state of incubation. * * * The body and walls of the nest are composed of rootlets and flower stalks of Spirea discolor, and the inner lining consists of fine rootlets and a very small quantity of vegetable down. It is a compactly built structure, measuring about 4 inches in outer diameter by 1³⁄₄ inches in depth; the inner cup measures 2 inches in width by 1¹⁄₈ inches in depth.

A few years later, O. W. Howard (1899) reported finding four nests in the Huachuca Mountains; one was about 30 feet up in the fork of a large limb of a red fir; another was in a sugar pine near the extremity of a limb and about 30 feet from the ground; a third was near the end of a long slender limb of a yellow pine, about 50 feet up, and well concealed among the long pine needles; the fourth was on a branch of a red fir, not far from the trunk, and over 60 feet from the ground.

F. C. Willard (1910), collecting in the Huachucas, says that “short-leaf pines, long-leaf pines and firs are chosen for the nesting sites.” One female that he watched building her nest "was gathering rootlets at the time and seemed very particular about them, picking up and dropping several before selecting one which she thought satisfactory. This she carried into a dense growth at the tip of a branch of a large fir about one hundred yards away. The male was singing and feeding in a tree close by. After a few trips with material the female would fly into the tree where he was and let him feed her. This is the only time I have observed nest building going on and the male not following the female in her flights.” In his description of the nest, he says: “It is supported by ten small live twigs from the size of a pencil down, all growing from a branch about five eighths of an inch in diameter. It is composed outwardly of moss and pine bud hulls with plant down scattered thruout. The proportion of this latter increases until the the lining is reacht where it forms a felt like a hummingbird’s nest. This lining is supplemented with a few very fine rootlets.”

He gives an interesting account of his attempts to locate another nest in “a short-leaf pine whose branches were weighted down with masses of twigs and cones.” He worked from ten in the morning until three in the afternoon, following the birds about, climbing the suspected tree several times and cutting off many twigs, before he finally found the nest. “The tree was not a very large one and I had shaken every branch and jarred them with my foot, but until I practically toucht the nest she had stayed on.”

While I was in Arizona with Willard he collected for me on May 30 a beautiful nest of the olive warbler, with four fresh eggs. It was taken at an altitude of 8,500 feet on the Huachuca Mountains and was built in a clump of mistletoe near the tip of a branch of a sugar pine about 20 feet out from the trunk and 55 feet from the ground. Its construction was similar to those described previously (pl. 23). The loftiest nest that he ever found was 70 feet from the ground in a pine.

The nest built by the Arizona olive warbler is beautiful, and quite different from that of any other species of its group. A typical nest (in the Thayer collection in Cambridge) is made mainly of a brown lichen or moss mixed with other lichens and mosses, bud scales, flower scales, and some plant down, reinforced with fine yellowish rootlets. All these are compactly worked into and supported by the living needles of the yellow pine in which the nest was built. The lining consists of plant down and finer strands of the same yellowish rootlets. It measures 3¹⁄₂ by 3 inches in outside diameter and 2¹⁄₂ in height; the inner cavity is about 2 inches in diameter and 1¹⁄₄ inches in depth.

Eggs.—Three or four distinctive eggs seem to constitute the full set for the northern olive warbler. These are ovate to short ovate and have a very slight lustre. They are grayish or bluish white, or even very pale blue, liberally speckled, spotted and blotched with “dark olive-gray,” “dark grayish olive,” “drab,” “olive-brown,” or “dark brownish drab.” These are interspersed with undertones of “mouse gray,” “deep mouse gray,” or “Quaker drab.” On some eggs the spots are sharp and distinct, while on others the olive, brown, and drab markings are clouded into the undertones. The spottings are usually well scattered over the entire surface, but tend to become heavier at the large end. The measurements of 28 eggs average 17.1 by 12.8 millimeters; the eggs showing the four extremes measure 19.0 by 16.0, 16.0 by 12.2, and 18.1 by 12.0 millimeters (Harris).

Young.—Information is lacking on incubation and care of the young.

Plumages.—The plumages and molts of the olive warbler are as distinctive as its nest and eggs. The sexes are not quite alike in juvenal plumage. Ridgway (1902) describes the young male as “pileum, hindneck, back, scapulars, rump, and upper tail-coverts plain dull olive or brownish olive; supra-auricular region and sides of neck dull yellowish buffy, the latter tinged with olive; chin, throat, and chest dull yellowish buffy; otherwise like adult female.” And of the young female, “similar to the young male but paler and grayer above; supra-auricular and post-auricular regions pale brownish buffy; chin, throat, and chest still paler buffy, the chin and upper throat dull buffy whitish.” The white tips of the greater wing coverts are tinged with yellowish.

I have not been able to trace the postjuvenal molt in the series I have examined but it apparently occurs in July and produces very little change, young birds of both sexes in their first winter plumage closely resembling the adult female at that season, though the crown and nape are grayer and the throat and breast are paler. I can find no evidence of a prenuptial molt. Young males evidently breed in this plumage and do not acquire the fully adult plumage until their second fall, or perhaps later. In Brewster’s series, collected in March, three males are in this condition, of which he (1882) says that “two of them, although in unworn dress, are absolutely undistinguishable from adults of the opposite sex; the third (No. 77), however, has the throat appreciably tinged with the brownish-saffron of the adult male.” This last may be a bird that is one year older, for Ridgway (1902) describes the “second year” male as “identical in coloration with the adult female.” Judging from the series that I have examined, including all of Brewster’s birds, I am inclined to think that the adult winter plumage is acquired at the first postnuptial molt, or when the bird is a little over one year old.

There can be no doubt, however, that young males breed in this immature plumage, for Price (1895) secured a pair that were feeding a brood of young, and the “male was not in fully adult plumage and was very similar in coloration to the female.” Swarth (1904) writes: “The male bird breeds in the immature plumage, for on June 21, 1902, I assisted O. W. Howard in securing a nest, containing four eggs, the parents of which were indistinguishable in color and markings. * * * I was surprised at the large proportion of birds in this immature plumage that were seen. At a very liberal estimate I should say that the males in adult plumage comprised barely a third of the birds seen in the spring.”

Adults have a complete postnuptial molt, mainly in July; all June birds that I have seen are in worn plumage, and August and September birds are in new, fresh feathers. The fall plumage of the male is similar to that of the spring male, but the colors of the head, neck, and chest are duller, more clay color, the back is more olive and the sides are browner. In the female at this season the crown is tipped with grayish and the throat and breast with buffy, while the sides are browner than in the spring; the white tips of the greater wing coverts are tinged with yellowish. The nuptial plumage is acquired mainly, if not entirely, by wear, the edgings wearing away and the colors becoming brighter.

Food.—Nothing definite seems to have been recorded on the food of the olive warbler, but its habit of creeping over the branches and twigs of the pines, much after the manner of the pine warbler, would seem to indicate that it was foraging for the many small insects that infest these trees. It is evidently one of the protectors of the pine forests. Brewster (1882b) says: “In their actions these Warblers reminded Mr. Stephens of Dendroeca occidentalis. They spent much of their time at the extremities of the pine branches where they searched among the bunches of needles for insects, with which their stomachs were usually well filled. Occasionally one was seen to pursue a falling insect to the ground, where it would alight for a moment before returning to the tree above.”

Behavior.—One of the members of Henshaw’s (1875) party brought in a specimen of this warbler, on September 20, “which he stated he had shot from among a flock of Audubon’s Warblers and Snowbirds, which he had started from the ground while walking the pine woods. With the rest, it had apparently been feeding upon the ground, and had flown up to a low branch of a pine, where it sat and began to give forth a very beautiful song, which he described as consisting of detached, melodious, whistling notes.”

W. E. D. Scott (1885), writing of his field work in the Santa Catalina Mountains in late November, says:

Associated with flocks of the Mexican Bluebird (Sialia, mexicana), which was, by the way, the only kind of Bluebird observed, was always to be found one and sometimes two representatives of the Olive Warbler (Peucedramus olivaceus). The Bluebirds were generally feeding on some insects in the tall pines, in flocks of from six to ten individuals. The Olive Warblers were on the best of terms with their blue friends, and as the Bluebirds were shy and restless they made it difficult to obtain or observe very closely their smaller allies. I did not in these pine woods see the two species apart, and became at length so well aware of the intimacy that existed between them, that I would fire at any small bird passing high overhead in company with Bluebirds. They were chance shots, certainly, but the only two small birds obtained flying in this way with the Bluebirds were Olive Warblers. * * * Generally they preferred the largest branches of the pines when they alighted, though I took one not more than three feet from the ground in a small bush. Their movements while feeding or searching for food are very deliberate, though I noticed now and again certain motions when at the extremity of a bough that reminded me of a Kinglet or a Titmouse.

Swarth (1940) says: “Though frequenting the tree tops to a great extent, they seem singularly tame and unsuspicious, and several times I have had one feeding in some of the lower branches, within arm’s reach of me, without its showing the least sign of fear.”

Voice.—The olive warbler has a rather loud, attractive, and distinctive note, but few observers have referred to it as a song. The “beautiful song” mentioned above consisted of “detached, melodious, whistling notes.”

One of its whistling notes sounds very much like the peto note of the tufted titmouse and might easily deceive the listener. Scott (1885) observed that these warblers “had a call-note so like that of their associates [the bluebirds] as to be almost identical. It seemed to me only a clearer whistle of more silvery tone.” Price (1895) saw a male alight on a twig near his mate, during nest-building, uttering “a liquid quirt, quirt, quirt, in a descending scale.” Mr. Henshaw (1875) heard “a few strange Vireo-like notes coming” from an olive warbler. A bird that Dr. W. P. Taylor (MS.) watched in apparent courtship gave “a whistled call with descending inflection.”

Field marks.—In general appearance and behavior the olive warbler suggests the pine warbler, especially as it creeps over the pines. The orange-brown head, neck, and breast of the adult male, with the conspicuous black band through the eye, is distinctive; these colors are much paler and more yellowish in the female, and the band through the eye is grayish. Both adults have two white wing bars, a white area at the base of the primaries and much white in the tail, the white areas being more restricted in the female. Young birds are much like the female (see descriptions of plumages).

Winter.—The olive warbler, as a species, is probably permanently resident throughout most of its Mexican and Central American range. But the northern olive warbler is evidently partially migratory, though some individuals, perhaps many, remain in Arizona during part, or all, of the winter. All of the 15 specimens taken by Stephens for William Brewster (1882b) were collected in March, probably too early to be migrants, and he says that Stephens had previously taken one in February 1880, evidently a wintering bird. Mr. Swarth (1904) writes: “I have not found this species very abundant in the Huachucas at any time, but it is probably resident to some extent, for I secured an adult male on February 21 when the snow was deep on the ground. During March I saw several more, all adult males and single birds, usually with a troop of Pygmy Nuthatches; but it was not until the first of April, when the other warblers were arriving, that they became at all abundant.” Scott (1885) found them on the Catalinas under winter conditions, with snow on the ground, and says: “I think there can be little if any doubt that they are residents all the year.” And Dr. W. P. Taylor (MS.) took one in the Santa Ritas on February 4, 1923. Just how far south go the birds that migrate away from Arizona does not seem to be known, but apparently they have not been detected beyond Chihuahua and Tamaulipas. Perhaps they do not migrate at all.

DISTRIBUTION

Range.—Southwestern United States to northern Nicaragua.

Breeding range.—The northern olive warbler breeds north to central Arizona (Baker’s Butte and White Mountains) and central western New Mexico (Reserve). East to western New Mexico (Reserve and McKnight’s Canyon); Chihuahua (Colonia García); southeastern Coahuila (Diamante Pass); and southwestern Tamaulipas (Miquihuana). South to southwestern Tamaulipas (Miquihuana) and southern Durango (Durango). West to Durango (Durango); Sonora (Sierra Saguaribo); and southeastern and central Arizona (Huachuca Mountains, Santa Catalina Mountains, and Baker’s Butte).

Other races occur in southern Mexico and Central America.

Winter range.—The northern olive warbler is probably migratory to some extent, individuals withdrawing to the southern part of the range, but it is found in winter occasionally or in small numbers as far north as southern Arizona.

Egg dates.—Arizona: 14 records, May 23 to July 1; 7 records, June 2 to 18, indicating the height of the season.

DENDROICA PETECHIA AESTIVA (Gmelin)

EASTERN YELLOW WARBLER

Plates 24, 25

HABITS

The familiar yellow warbler, also commonly called the summer yellow bird or wild canary, is the best known and the most widely known of all of our wood warblers. It is one of the few birds that almost everybody knows by one of the above names. It is universally beloved as it comes to us in the flush of budding spring, gleaming in the shrubbery, like a rich yellow flame among the freshly opening leaves, or bringing to the apple orchards a flash of brilliant sunshine to mingle with the fragrant blossoms. As Dr. Chapman (1907) says: “In his plumes dwells the gold of the sun, in his voice its brightness and good cheer. We have not to seek him in the depths of the forest, the haunt of nearly all his congeners, he comes to us and makes his home near ours.”

The yellow warbler, as a species, is also the most widely distributed member of its family. Its breeding range extends from the Atlantic to the Pacific in both Canada and the United States (110 degrees of longitude), and from the Barren Grounds in northern Canada to Mexico and the Gulf States (40 degrees of latitude). Its winter range covers 54 degrees of longitude and 31 degrees of latitude in Central and South America. Professor Cooke (1904) says: “The extreme points of the yellow warbler’s range—northern Alaska and western Perú—are farther separated than the extremes of the range of the black-polled warbler, which is considered the greatest migrant of the family.” But it must be remembered that the yellow warbler breeds much farther south than the black-poll.

Spring.—The spring migration of the yellow warbler is long and partially circuitous; eastern yellow warblers that winter as far east as British Guiana probably make a roundabout flight to Central America, as there seem to be no springtime records for this bird in the West Indies and few for it in Florida. These birds may fly across the Gulf from Yucatán to Cuba and Florida, but the main flight is probably directly north from Yucatán to Louisiana and other points on the Gulf coast; they have been repeatedly seen flying northward in the middle of the Gulf. There is also a considerable migration along the coast of Texas, which I have personally observed.

The migration is also prolonged or very irregular, for according to the dates of departure given to me by Alexander F. Skutch (see under Winter), the last of these warblers do not leave Central America until the very last of April, or the first of May, after the first arrivals have reached New England; some of these records, however, may apply to one of the western races. After the birds reach the United States, the migration fans out northward and northeastward and seems to be more rapid. Of this Frederick C. Lincoln (1939) says: “Coming north from the Tropics these birds reach New Orleans about April 5, when the average temperature is 65° F. Travelling on northward much faster than does the season, they reach their breeding grounds in Manitoba the latter part of May, when the average temperature is only 47°. Encountering progressively colder weather over their entire route, they cross a strip of country in the 15 days from May 11 to 25 that spring takes 35 days to cross. This ‘catching up’ with spring is characteristic of species that winter south of the United States and of most of the northern species that winter in the Gulf States.”

Territory.—Soon after their arrival on their breeding grounds the males begin to select their territories and then to defend them. Dr. S. Charles Kendeigh (1941) made a study of the territories of birds in a prairie community in northwestern Iowa, and writes:

A special study of the Yellow Warbler indicated that territorial requirements included suitable nest-sites, concealing cover, tall singing posts, feeding areas in trees, and space, and that when certain of these factors were lacking, territorial relations became confused and the behavior of the birds was modified. * * * These warblers possessed territories that averaged about 150 feet in diameter, or approximately two-fifths of an acre. Even in locations where trees were included, the territories appeared to be of about the same size. The limits of the territory often did not coincide with the boundaries of the thicket in which the nest was located but extended over the neighboring grassland and often included parts of neighboring thickets. These territories were defended by the males partly by singing, although in shrubby areas lacking trees they were handicapped by lack of singing posts from which to proclaim their ownership and to advertise themselves. A few made use of fences from which to sing and also of tall posts and wire from an abandoned electric line that extended through the area. The rôle of the female in defense of territory was not determined.

Probably due to this lack of singing posts and to the unusual abundance of birds, chasing was also extensively used as a defense measure, and during the height of the nesting season squabbling birds were a common sight all over the area. * * * Neighboring males seemed to lack any conception of the limits of each other’s territories and moved about indiscriminately until chased out. No actual fighting was observed. * * * In other parts of the area where trees were available, the males commonly sang at a height of 18 feet, often up to a height of 45 feet, and chasing was not often observed.

For yellow warblers observed by Wendell P. Smith (1943) at Wells River, Vt., “territorial exclusiveness scarcely existed. In one season a Chestnut-sided Warbler’s nest was located within five feet of that of the Yellow Warbler. The following species were represented by one nesting pair within a radius of thirty feet: House Wren, Catbird, Black and White Warbler, Chestnut-sided Warbler, Northern Yellow-throat and Indigo Bunting. Unless another individual came very close to the nest, no hostility was shown by either male or female. Too close an approach would bring a swift attack by one or the other, however, but for only a short distance when the pursuer would give up the chase.”

A. D. Du Bois mentions in his notes a nest that was about 6 feet from the door of a screened porch in daily use and tells the following story about the territory involved: “Twelve yards south of this nest was a spruce tree. On several occasions the male met another male at this tree or beyond it. Both alighted at times in the treetop. Their boundary arguments had the appearance of pushing-contests in the air; and sometimes the contestants revolved in the air, about an imaginary axis between them. Once, while one of the warblers was in the tree, the other was seen to poise near the tree on fluttering wings, remaining for two or three seconds as nearly stationary in the air as a hummingbird. Twelve yards beyond the spruce I found a nearly completed nest in tall lilacs; but this nest was not finally occupied.” Apparently, a second pair of warblers had tried to build a nest too near the territory of the first pair and had been driven out of the territory.

Courtship.—Mr. Smith (1943) says on this subject:

Courtship begins soon after arrival of the species. Within a period of from four to six days greatly increased singing is noted which marks its inception. Persistent and lively pursuit of the female by the male was observed, taking place within a restricted area (once within a radius of thirty feet). From one to four days elapsed before courtship was completed. Sexual union may not take place until nest building begins as the following observations in 1938 tend to show. Pursuit of the female began on May 23, continued on the 24th but frequent attempts at intercourse on the part of the male were unsuccessful. On the 26th copulation was seen to take place and on that date the nest was completed. * * * A period of several days intervened between nest completion and egg laying. During two seasons of rather intensive observation, this was two days.

Nesting.—Although we have come to regard the yellow warbler as a sociable and friendly little bird that seeks our company and builds its nest in the shrubbery about our homes, often close to our houses or in the bushes under our windows, such were not the original nesting sites and even now are far from being the commonest situations chosen, although they may seem the most evident.

The favorite nesting sites in southern New England are along small streams and brooks, around the borders of swamps and ponds and lakes, or in the more open brushy swamps (where the land is moist but not too wet) among willows, alders, elderberry and blueberry bushes, and other moisture-loving shrubs and small trees. They also nest in drier situations, in shrubbery about open spaces, along brush-grown fences and hedgerows and roadside thickets, or in cut-over lands grown up to sprouts and to thickets of wild raspberry, blueberry, and other bushes.

In such situations the nest is built in an upright fork or crotch of a bush or sapling, seldom over 6 or 8 feet from the ground or less than 3. Nests are sometimes built at higher levels in apple trees in orchards or in small trees about houses but rarely as high as 30 or 40 feet. Near human habitations, clumps of lilac bushes, often close to windows or doors, are decided favorites, while various kinds of ornamental shrubs about our gardens or grounds also provide suitable nesting sites.

Mr. Du Bois has sent me the data for 30 nests of the eastern yellow warbler found in Minnesota, Illinois, and New York. Among these, 4 were in willows, 3 each in lilacs and alders, 2 each in elms and boxelder saplings, and 1 each in a grapevine, an ash sapling, a spirea bush, and a currant bush. One of these latter, in an unspecified bush, was 14 feet from the ground, and another, in a wild grapevine climbing on a tree beside a coalbin, was 8 feet from the ground; those in the elms were 12 and 14 feet, respectively, from the ground. The remainder were mostly 5 feet or less above ground, the lowest being at a height of 2 feet, in a currant bush near a vegetable garden. He tells of a nest that was built in a wild rose bush at the edge of a small run near his vegetable garden; “this nest was so compactly fabricated as to hold water for some time; I saw about one-fourth inch of water standing in the bottom of it after a heavy rain.”

On two occasions, he has found the new nest to have been built on top of the old nest of the previous year.

F. G. Schrantz (1943) has published the results of a careful study of 41 nests of the eastern yellow warbler in Iowa, during 1938 and 1939, on the restricted grounds of the Iowa Lakeside Laboratory. Among those at heights from 1¹⁄₂ to 5 feet from the ground were 27 in wolfberry bushes (Symphoricarpos occidentalis), 8 in young saplings of boxelder (Acer negundo), 2 in wild gooseberry (Ribes gracile), 1 in wild currant (Ribes floridum), and 1 in an introduced species of honeysuckle. One nest was in a cottonwood at a height of about 10 feet, and another in a boxelder about 15 feet above ground.

Dr. Roberts (1936) says that in the prairie regions of Minnesota, where underbrush is scarce, the yellow warblers build their nests in the cottonwoods in the tree-claims, “against the trunks of the large trees, supporting them on small lateral branches and twigs. * * * These arboreal nests are often fifteen to twenty-five feet from the ground and occasionally still higher.” And in the huge cottonwood trees along the river, he has seen nests placed at elevations of 40 to 60 feet. Others have also recorded nests at heights of 40 and 60 feet.

In Dr. Kendeigh’s (1941) prairie community, “twenty out of twenty-nine nests were placed in buckbrush, with the rest in boxelder, lilac, willow, or currant. The buckbrush is a low bush usually three or four feet high, growing in rather dense thickets in the open, especially in grassy areas of Poa and Agropyron. Nests placed here varied between two and three feet above the ground. The nest found closest to the ground (18 inches) was, however, in a small boxelder. In taller shrubs and trees, the nests were found up to about seven feet above the ground.”

Mr. Schrantz (1943) watched the building of a nest from the first stages of construction to its completion and the laying of the first egg, covering a period of 4 days.

Construction was first observed at 7:45 a. m., on June 12, 1939, when a female Yellow Warbler was seen carrying a tuft of plant-down into a small boxelder sapling. Upon examination, a mass of plant-down about one and one-half inches in diameter was found at a measured height of two feet three inches from the ground in the fork of the sapling. During an hour of observation the female continued to carry plant-down at intervals of about four minutes although once it did not bring any material for twenty minutes. At noon the plant-down mass had increased to about three inches in diameter and was more compactly pushed into the fork. By 6:45 p.m., there were many strands of plant fibers and grasses woven around and through the plant-down in such a way as to wrap and bind the plant-down around the small twigs of the fork. The nest was just assuming a cup-shaped structure. The female was now bringing large loads of a mixture of grasses and plant fibers and working at a rate of about one trip every four minutes. The first day’s building was completed at 7:55 p.m. The nest was now partially surrounded with woven plant fibers and grasses with a slight formation of a rim.

On the second day the work continued and the “rim consisted of plant fibers and grasses woven partly into the original down but mostly into the sides and around the top. At 6:45 p.m., the nest appeared completed with a well-formed cup, plant-fiber and grass rim, and a plant-down floor.” The third day was partly rainy and little was accomplished but “by 8:00 on the fourth morning, the plant-down inside the nest was smoothed out and contained a few strands of fine grasses. * * * During all the observations on the building of this nest the male at no time was seen to bring any nest material. However, since there were many hours during the day when no observations were made, it is possible that he might have helped at some time. * * * At 6:30 a.m., the following day, one egg was found in the nest. * * * The dates of the beginning of construction and the dates the first eggs were laid were obtained for two other nests, and the time which elapsed in both cases was four days.”

Only the female was seen to take part in the building of the nest that Mr. Smith (1943) watched, but my experience was somewhat different. On May 10, 1942, I found a pair of yellow warblers building a nest in the top crotch of a blueberry bush, close to the side of a country road. They were very tame and gave me an unusual opportunity to watch them for over an hour at short range. I parked my car within 5 feet of the nest and took motion and still pictures, with cameras even nearer. The nest was nearly done and they were putting in the lining. Both birds helped in the work, but the female did nine-tenths of it. She came at frequent but rather irregular intervals, bringing a billful of soft plant down that looked like the down from ferns, some of which I found growing nearby, and to which I saw her making frequent trips; the fronds of the cinnamon ferns were just unfolding. This material she deposited in the cup of the nest and settled her body down into it, smoothing the lining into place by turning her body around in different directions, pressing it down with her body and up against the sides of the cup with a sidewise motion of the wings. Occasionally she reached over the rim of the nest, smoothing it with her neck and tucking in the loose ends with her bill. The bottom and outside of the nest seemed to be about finished; one side of it, opposite the most exposed side, was anchored to a nearby twig with strands of plant fiber. The female seemed utterly fearless; the male was more shy, but his streaked breast was occasionally seen at the nest.

Robie W. Tufts tells me that he has seen the male at the nest; he saw a male come to a partly finished nest sit in it for over a minute as though testing the workmanship and sing twice while sitting there. The male is always very attentive during nest-building, following his mate back and forth on her trips for material and keeping close to her most of the time. His interest in the nest is so keen that it would be strange if he did not sometimes help.

The eastern yellow warbler builds a neat, strong nest, the materials being firmly and smoothly interwoven and the lining compactly felted. Five local nests before me show quite a variation in the materials used and in their arrangement. The most obvious material, occurring more or less in all of the nests, consists of the silvery-gray strands from the last-year’s stalks of milkweed, Indian hemp, or other similar dead weeds. One nest has a great mass of such material below it on one side, evidently to fill in space in the fork that supported it; mixed with this material are a few strands of grasses, other shredded weed stems, bits of wool, and gray fur. Although this nest is far from neat externally, the cup of the nest is well and firmly made of finer silvery fibers and fine grasses, cinnamon-fern down, with which it is profusely lined, and a few fine white hairs. The rim is strongly reinforced with horsehair and decorated with the cinnamon down. This nest, the largest of the lot, measures nearly 5 inches in height and 3 inches in diameter, externally. The smallest and the neatest of the five is made of finer strands of similar materials, without a trace of cinnamon-fern down, the whole being very firmly and smoothly woven into a compact little nest; the rim is neatly made of very fine grasses, and it is smoothly lined with white plant-down; it measures only 2 inches in height and 2¹⁄₄ inches in diameter, externally. Grasses enter largely into the construction of all the nests. One in particular is lined with both white and buff plant-down and a little very fine grass, and has a solidly built rim of strong grasses very firmly interwoven; the foundation consists of dry brown and gray lichens, or mosses, and a lot of cotton waste, such as is used to clean machinery. A two-story nest, which measures 4 inches in total height, is profusely lined with white cotton in both stories. There is little difference in the internal measurements, which vary from 1³⁄₄ to 2 inches in diameter, and from 1¹⁄₄ to 1¹⁄₂ inches in depth.