Front matter (continued 8)

DISTRIBUTION

Range.—Eastern North America, from southern Canada to northern South America.

Breeding range.—The black-throated blue warbler breeds north to southwestern and central Ontario (Lac Seul, Kapuskasing, and Lake Timiskaming); and southern Quebec (Blue Sea Lake, Quebec, Godbout, and Mingan). East to southern Quebec (Mingan, Grand Grève, and the Magdalen Islands); eastern Nova Scotia (Cape Breton Island and Halifax); southern Maine (Ellsworth and Auburn); southeastern Massachusetts (Taunton); Connecticut (Hadlyme); northeastern Pennsylvania (Lords Valley and Pocono Mountain); and southward through the Alleghanies to Northwestern South Carolina (Mountain Rest); northeastern Georgia (Rabun Bald, Brasstown Bald, and Young Harris). South to northern Georgia (Young Harris); southeastern Tennessee (Beersheba Springs); southeastern Kentucky (Log Mountain and Black Mountain); northeastern Ohio (Wayne Township and Pymatuning Bog); northern Michigan (Douglas Lake and Wequetonsing); northern Wisconsin (Fish Creek, Mamie Lake, and Perkinstown); and northern Minnesota (Kingsdale, Cass Lake, and White Earth; possibly sometimes near Minneapolis). West to northern Minnesota (White Earth) and western Ontario (Lac Seul). The species very probably breeds rarely in Manitoba or Saskatchewan where there are as yet only a few records and it is a recent arrival. At Emma Lake, Saskatchewan, 40 miles north of Prince Albert, 5 were observed June 27 to July 2, 1939. The first record for the Province was a specimen collected on October 21, 1936, at Percival, 100 miles east of Regina. It is a rare but tolerably regular migrant through eastern North and South Dakota, suggesting that there is some as yet unknown breeding area. The species has been recorded in migration, more often in fall, in Wyoming, Colorado, Nebraska, Kansas, Oklahoma, and Texas.

Observers at Aweme, Manitoba, in 38 years recorded it only twice. Another observer at Eastend, southwestern Saskatchewan, recorded it for the first time on September 21, 1937, after at least twenty years of continuous observation.

On the basis of such information it seems probable that the species is slowly spreading its breeding range westward.

Winter range.—The principal winter home of the black-throated blue warbler is in the West Indies where it is found north to the Bahamas (Andros, Nassau, and Watling Islands). East to Puerto Rico (Río Piedras) and the Virgin Islands (St. Croix). South to Puerto Rico (Maricas); Hispaniola (Paraíso, Dominican Republic; and Jérémie, Haiti); Jamaica (Spanishtown); and the Swan Islands. West to the Swan Islands; Cozumel Island; Cuba (Habana); and the Bahamas (Andros). It is also casual north to southern Florida (Sanibel Island, Key West, and Sombrero Key); accidental in Guatemala (Cobán); and in northern South America; Venezuela (Ocumare and Rancho Grande); and Colombia (Las Nubes, Santa Marta region, and Pueblo Viejo).

The species as outlined is divided into two subspecies or geographic races. The black-throated blue warbler (D. c. caerulescens) is found in Canada and in the United States south to Pennsylvania; Cairns' warbler (D. c. cairnsi) breeds in the Appalachian Mountains from southwestern Pennsylvania southward.

Migration.—Late dates of departure from the winter home are: Puerto Rico—Consumo, April 3. Haiti—Morne à Cabrits, May 6. Cuba—Habana, May 11. Bahamas—Cay Lobos, May 14.

Early dates of spring arrival are: Florida—Fort Myers, March 4. Georgia—Fitzgerald, April 11. South Carolina—Spartanburg, April 5. North Carolina—Weaverville, April 19. Virginia—Lynchburg, April 21. District of Columbia—Washington, April 19. Pennsylvania—Swarthmore, April 25. New York—New York, April 28. Massachusetts—Amherst, May 2. New Hampshire—East Westmoreland, April 29. Maine—Auburn, May 3. Nova Scotia—Scotch Lake, May 7. Quebec—Quebec, May 7. Louisiana—New Orleans, March 22. Tennessee—Chattanooga, April 14. Kentucky—Lexington, April 24. Illinois—Urbana, April 26. Ohio—Canton, April 22. Michigan—Battle Creek, April 28. Ontario—Reaboro, May 3. Missouri—St. Louis, April 18. Iowa—Sigourney, April 21. Wisconsin—Ripon, April 28. Minnesota—Hibbing, May 8.

Late dates of the departure of transients in spring are: Florida—Daytona Beach, May 21. Georgia—Darien, May 20. South Carolina—Clemson (College), May 15. North Carolina—Raleigh, May 19. Virginia—Charlottesville, May 22. District of Columbia—Washington, May 30. Pennsylvania—Berwyn, June 3. Ohio—Ashtabula, May 29. Indiana—Fort Wayne, June 2. Michigan—Detroit, June 2. Illinois—Lake Forest, June 8. Wisconsin—Racine, June 4. Iowa—National, May 27.

Late dates of fall departure are: North Dakota—Fargo, October 21 (bird banded). Minnesota—Minneapolis, October 3. Wisconsin—Milwaukee, October 16. Iowa—Sigourney, October 20. Illinois—Chicago, October 25. Michigan—Grand Rapids, November 1. Indiana—Indianapolis, October 14. Ontario—Port Dover, October 27. Ohio—Medina, October 30. Kentucky—Eubank, October 22. Tennessee—Athens, October 18. Mississippi—Gulfport, October 12. Quebec—Montreal, October 15. New Brunswick—Saint John, October 11. Maine—Portland, October 17. New Hampshire—Water Village, October 8. Massachusetts—Cambridge, November 7. New York—Fire Island, October 24. Pennsylvania—Harrisburg, October 24. District of Columbia—Washington, October 29. Virginia—Lexington, October 15. North Carolina—Highlands, November 14. South Carolina—Clemson (College), October 17. Georgia—Athens, November 2. Florida—Fernandina, November 15.

Early dates of fall arrival are: Wisconsin—New London, August 23. Michigan—Grand Rapids, August 26. Ohio—Toledo, August 24. Illinois—La Grange, August 24. District of Columbia—Washington, August 21. Virginia—Charlottesville, September 12. North Carolina—Mount Mitchell, September 1. South Carolina—Mount Pleasant, August 30. Georgia—Savannah, August 28. Florida—Coconut Grove, August 29. Cuba—Cienfuegos, September 2. Dominican Republic—El Río, October 5. Puerto Rico—Las Marías, October 12.

Casual records.—On the Farallon Islands, Calif., a specimen was found dead on November 17, 1886; it had been previously observed for three weeks. In New Mexico a specimen was taken at Gallinas Mountain on October 8, 1904, and on October 9, 1938 another was collected in Milk Ranch Canyon near Fort Wingate. In Bermuda a specimen was collected October 2, 1902; and it is considered a rare winter visitor. An individual spending the winter at a feeding stand in the suburbs of Washington, D. C., was observed closely from December 22, 1930, to January 16, 1931.

At sea the black-throated blue warbler has been observed on October 27, 1921, 12 hours run out from Port-au-Prince, Haiti, toward New York; and on March 29, 1918, in the Gulf of Mexico, 125 miles from Sabine Pass, La.

Destruction at lighthouses.—Lighthouses with fixed white lights have caused considerable destruction of bird life during migration and the black-throated blue warbler seems to have been especially lured to those in southern Florida. Records were received from several of these lighthouses over a period of 5 or 6 years. Those from Sombrero Key are most detailed and give an interesting picture of migration at that point, since they include date, weather conditions, number of birds that struck, number killed, and hours during which the birds struck the light.

Comparatively fewer birds struck the light in spring than in fall. The spring dates are from March 9 to May 29; but in 4 years birds are reported to have struck the light only on 24 nights and 4 individuals is the greatest number reported.

In the fall, the records extend from September 3 to December 5, the heaviest nights being from the middle of September to late October. In two different years birds struck the light on 19 nights in two months. The greatest number in one night was 400 with 56 killed. In one of those years 1146 birds struck the light; of these 193 were killed. It was not only on stormy nights that the birds were attracted, as 130 struck and 15 were killed on a night described as calm and dark. Sometimes they kept striking all night, but on others the flight seems to have been concentrated, as when 300 birds struck in 3¹⁄₂ hours. On a few occasions the mortality was as high as one-third of the birds that struck.

On the night of January 26, 1886, two birds struck the light. These were either wintering birds or extremely early migrants.

Egg dates.—Massachusetts: 6 records, May 28 to July 5; 3 records, June 2 to 8.

New Hampshire: 17 records, June 3 to 22; 9 records, June 10 to 15.

New York: 51 records, May 29 to June 20; 37 records, June 3 to 12, indicating the height of the season.

Pennsylvania: 57 records, May 25 to June 26; 32 records, May 30 to June 6.

North Carolina: 10 records, May 5 to June 22; 6 records, June 4 to 11.

Virginia: 19 records, May 26 to June 18; 14 records, May 27 to June 4 (Harris).

DENDROICA CAERULESCENS CAIRNSI Coues

CAIRNS’ WARBLER

Plate 31

HABITS

This local race of the black-throated blue warbler, breeding in the southern Alleghenies, was named by Dr. Elliott Coues (1897) in honor of its discoverer and original describer, John S. Cairns of Weaverville, N.C. Dr. Coues, at that time, mentioned only the characters of the male, but those of the female are fully as well, perhaps more satisfactorily, marked than those of the male. Ridgway (1902) describes both very well and concisely as follows:

“Similar to D. c. caerulescens, but adult male darker above, especially the pileum, which is not lighter blue than the back, the latter usually more or less spotted or clouded with black, sometimes chiefly black, the pileum sometimes streaked with black; adult female darker and duller olive above and less yellowish beneath, with the olive of flanks darker and more strongly contrasted with the pale olive-yellowish of abdomen.” In discussing its distribution, he was unable to define its breeding range with any degree of accuracy; and adds in a footnote: “On the whole, the form is not a very satisfactory one, one of the two characters on which it was based (smaller size) failing altogether (D. c. cairnsi averaging slightly larger, in fact, than D. c. caerulescens), and the other only partially so, since many specimens of D. c. cairnsi have little if any black on the back, while many of D. c. caerulescens have quite as much as the average amount shown in D. c. cairnsi.”

The 1931 A. O. U. Check-List gives the breeding range of cairnsi as from Maryland to Georgia, but no definite line can be drawn; birds from southern Pennsylvania and Maryland, and perhaps the Virginias, are variably intermediate in their characters, and specimens can be found that are referable to either one or the other form.

Before this race had been separated from the northern form, Cairns (1896) wrote of its haunts:

High up on the heavily timbered mountain ranges of western North Carolina is the summer home of the Black-throated Blue Warbler.

Here in precipitous ravines, amid tangled vines and moss-covered logs, where the sun’s rays never penetrate the rank vegetation and the air is always cool, dwells the happy little creature, filling the woods from dawn to twilight with its song. * * *

These birds are a local race; breeding from one generation to another. They arrive from the south nearly ten days earlier than those that pass through the valleys on their northward migration. It is common to observe migrants through the valleys while breeders on the higher mountains are already nest-building and rearing their young.

This statement agrees with Professor Cooke’s (1904) later data, and with his statement: “The species is one of the few that appear in the mountains earlier than on the plains, and the case seems to sustain the theory that the individuals of a species that breed farthest south are the first to migrate in the spring.”

Nesting.—Cairns (1896) writes on this subject:

Nesting begins in May and continues until the end of June. The nests are placed in various shrubs, such as laurel, wild gooseberry, and chestnut, but the blue cohosh or papoose-root (Caulophyllum thalictroides) seems to be the favorite. These thick weeds grow rapidly to a height of from three to five feet, entirely hiding the ground, and thus afford the birds considerable protection. * * * The nests are never placed over three feet from the ground; usually about eighteen inches; one I examined was only six inches. * * *

The nests show little variation in their construction, though some are more substantially built than others. Exteriorly they are composed of rhododendron or grapevine bark, interwoven with birch-bark, moss, spider-webs, and occasionally bits of rotten wood. The interior is neatly lined with hair-like moss, resembling fine black roots, mixed with a few sprays of bright red moss, forming a strikingly beautiful contrast to the pearly eggs. The female gathers all the materials, and builds rapidly, usually completing a nest in from four to six days if the weather is favorable. She is usually accompanied by the male, which, however, does not assist her in any way.

Bruce P. Tyler of Johnson City, Tenn., has sent me some fine photographs (pl. 31) of the nests of this warbler, and says in his notes: “The Cairns warbler is found breeding in May, and later, on the southerly slope of Beech Mountain, just across the Tennessee line in North Carolina, at an elevation of 4,800 to 5,200 feet above sea level. The nest is built in small upright saplings or sprouts, 3 to 4 feet above the ground, and is constructed of shredded bark from the dying chestnut trees, rotten wood, etc., bound together with spiders’ webs, and lined with fern rootlets and fine grass.”

Thomas D. Burleigh (1927a) records four nests found, during May and June, on the slopes of Brasstown Bald in the northeastern part of Georgia: Two of these were in laurel bushes, 2 and 2¹⁄₂ feet from the ground; another was 2 feet up in the fork of a small viburnum; and the fourth was 5 feet from the ground, “saddled near the end of a drooping limb of a rhododendron at the base of a large yellow birch well up the mountainside.” A nest in my collection was taken by H. H. Bailey in Giles County, Va., at an elevation of 4,000 feet, on May 22, 1914; it was placed in a horsechestnut sprout alongside of a road, 1 foot above the ground. This and another nest before me are very similar to those described above.

Eggs.—The 3 or 4 eggs laid by Cairn’s warbler are practically indistinguishable from those of the black-throated blue warbler. The measurements of 30 eggs average 17.3 by 12.7 millimeters; the eggs showing the four extremes measure 19.0 by 13.0, 17.9 by 13.4, and 16.0 by 12.0 millimeters (Harris).

DENDROICA CORONATA CORONATA (Linnaeus)

EASTERN MYRTLE WARBLER

Plates 31-33

HABITS

We used to call this the yellow-rumped warbler, a none too distinctive name, as other warblers have yellow rumps. Another early and slightly better name, “yellow-crowned wood warbler,” reflected the scientific name coronata and was based on the old Edwards name “golden-crowned fly-catcher.” The present name, Eastern myrtle warbler, comes from its fondness for the berries of the waxmyrtle (Myrica cerifera); and in the south, where it is common in winter, it is often called the myrtlebird.

Next to the yellow warbler, this is probably the best known of the wood warblers and is about the second one of the group that the novice learns to recognize. All through the eastern United States this is by far the most abundant warbler on both migrations, being about the first to arrive in the spring and the last to leave in the fall, often remaining all winter nearly up to the southern limits of its breeding range. It is a large, conspicuous warbler, not at all shy, and is to be found almost anywhere, often in enormous numbers. The breeding range of the species is one of the most extensive, extending from the tree limit in Alaska and northern Canada down through the coniferous forests into the northern tier of States, and even farther south in the mountains. Its winter range is still more extensive. It spends the winter farther north than any other wood warbler, although more or less sparingly and irregularly in the northern States, and its range extends through the Bahamas, the northern West Indies, Mexico, and Central America to Panamá. There is no wonder that it is well known. But neither Wilson, Audubon, nor Nuttall ever found its nest.

Spring.—Professor Cooke (1904) writes:

The myrtle warbler is one of the first migrants to move northward. A large flight struck the Alligator Reef lighthouse February 23, 1892, and some 60 birds struck the Sombrero Key lighthouse March 3, 1889. By the middle of March migration is well under way over all the winter range, and the foremost birds keep close behind the disappearance of frost. * * * By the last of March all the myrtle warblers have departed from Jamaica, Haiti, Cuba, and the Bahamas. The latest recorded date of striking of this species at any of the Florida lighthouses is April 3, 1889. By the middle of the month the latest northbound birds have left southern Florida. * * * Most of the migrants cross the Rio Grande into Texas about the middle of March, and it is the middle of April before the last have passed north.

Charles L. Whittle (1922) witnessed a heavy migration of myrtle warblers along the coastal islands of South Carolina on March 4, 1920, that seemed to have been influenced largely by the presence of the waxmyrtle (Myrica cerifera). He says:

Perhaps half a mile from the northeast end of Sullivan Island the belt of waxmyrtle trees narrows to a width, measured northwest and southeast, of about three hundred feet. Here, near a seashore resort, a road had been recently cut across the belt of waxmyrtle trees at right angles to the sand bar. Streams of warblers flying along the shore northeasterly from Folly and Morris Islands, just south of the entrance to Charleston harbor, dropped to the land and converged at the southwest end of the mantle of myrtle trees and passed across the open swath cut for the new road. Posting ourselves here we counted the birds moving northeast, minute by minute as they passed the opening, for half an hour. The flight was continuous, many of the birds lighting on the ground and trees from time to time, and the number crossing per minute varied from twenty to two hundred, and accordingly averaged about one hundred per minute. As far as we could judge the number was no greater than it had been all the time since our arrival at the shore. Taking, therefore, the average at one hundred per minute, 24,000 Myrtle Warblers passed northward between nine in the morning and one in the afternoon. Not only so, but additional warblers passed close by both to the east and to the west of the stream of birds under observation. No doubt also the migration began prior to nine in the morning and did not cease at one in the afternoon.

He points out that the northern species of myrtle, or bayberry (Myrica pensylvanica), extends all along the coast from New Brunswick and Nova Scotia to Florida; and he suggests that if these warblers prefer to migrate along a coastal route where these myrtles reach their maximum development and where the climate may be milder than at higher elevations inland, it may explain why they generally arrive in New Brunswick a week earlier than in Pennsylvania.

Milton P. Skinner (1928) says that, in the North Carolina sandhills, “early in March the movement becomes conspicuous, and great numbers of these warblers are then seen constantly moving through the forests and across the fields in steady streams, flitting about a few minutes, and then passing on to the northeast. These movements are near the ground, or among the tree trunks, but at other times the birds are above the tallest trees. The general direction is from the southwest to the northeast, with fifty to a hundred warblers passing over a field each hour of every day for at least two weeks.”

At Buckeye Lake, Ohio, according to Milton B. Trautman (1940)—

No warbler species migrated through the area in such consistently large numbers as did the Myrtle Warbler, and none had a more prolonged spring or fall migration. The first spring transients, mostly brilliant colored males, were generally seen between April 12 and 20. Thereafter the number of individuals increased rapidly, and from May 1 to May 5 between 100 and 200 birds, mostly males, could generally be daily noted. A marked decrease usually followed this migration wave. Between May 10 and 18, during the period of maximum numbers for most warbler species, there was a second large wave and then 150 to 500, mostly females and young males, were observed daily. A drastic decline in numbers took place shortly after May 18, and by May 23 few or none remained.

The migration is about the same in Massachusetts. The birds come in waves, the adult males preceding the females. We usually see the first arrivals about the middle of April, drifting through the leafless tree-tops in the tall deciduous woods where we look for hawks’ nests; in their brilliant new plumage with gleaming yellow patches they are easily recognized as myrtle warblers, even in the tops of the 60-foot trees. Mr. Forbush (1929) gives this picture of the later waves:

In the latter days of April or very early in May when the south wind blows, when houstonias and violets begin to bloom on sunny southern slopes, when the wild cherry and apple trees and some of the birches, sumacs and the shrubbery in sheltered sunny nooks begin to put out a misty greenery of tiny leaflets, then we may look for the Myrtle Warblers, the males lovely in their nuptial dress of blue-gray, black, white and lemon-yellow. Then they may be found fluttering about in sheltered bushy bogs, catching the early insects that dance in the sunshine along the water-side. All through early May they move northward, or westward toward the mountains, migrating by day or night indifferently as the case may be.

Soon most of them have passed beyond our borders and reached their summer homes in the coniferous forests of the Canadian Zone, the first of the family to come, close on the heels of retreating winter and while frost and snow still linger in the northern woods.

Courtship.—The courtship of the myrtle warbler must be a very pretty performance. Two brief accounts of it have been published: "As summer approaches the males begin their courtship of the females, following them about and displaying their beauties by fluffing out the feathers of their sides, raising their wings and erecting the feathers of the crown, so as to exhibit to the full their beautiful black and yellow markings. After much time spent in courting they mate, and at once look about for a nesting place" (Forbush, 1929). Males seeking mates “made advances to the female contingency, hopping from twig to twig with outspread wings, chipping and fluttering, now repulsed by the fair one, and now accepted by another one to whom advances were made, to finally spend a few days in a favorable spot and begin nest building” (Knight, 1908).

Nesting.—On August 1, 1907, at Clarkes Harbor, Nova Scotia, I found the first and only nest of the myrtle warbler that I have ever seen; it was about 15 feet from the ground on a horizontal branch of a large spruce tree, about 5 feet out from the trunk, and contained three young birds that were nearly fully feathered. Robie W. Tufts says in his Nova Scotia notes: “I have seen these nests built at varying heights from 5 to 50 feet high. One found on June 6, 1919, contained four slightly incubated eggs. It was placed close to the stem of a pine tree, near the top, about 50 feet up. My field experiences tend to support the theory that these birds normally raise two broods a year.” He found one nest built in an apple tree in an orchard, of which he says: “Of the large number of nests of this species I have examined, this is the only one not built in a conifer.”

There are two Nova Scotia nests of the myrtle warbler in the Thayer collection in Cambridge, both taken by H. F. Tufts. They are slightly different in composition and structure, but are probably fairly typical of the species. One, found saddled on a spruce limb 10 feet from the ground, is rather bulky and loosely built; the foundation and sides are made of fine coniferous twigs mixed on the bottom with grasses and rootlets and around the rim firmly interwoven with black horsehair, or perhaps moose hair, and finer rootlets; the cup is smoothly lined with finer hair and feathers. Externally it measures, roughly, 4 by 5 inches in diameter and about 2 inches in height; the cup is about 2 inches in diameter and 1³⁄₄ inches deep. The other, a very pretty nest found 8 feet up in a small spruce, close to the trunk, is more firmly and compactly built; the base and sides are made up mainly of green mosses and a few gray lichens mixed with fine twigs and a few fine grasses, all firmly interwoven; internally the cup is smoothly lined with fine black and white hairs on top of a few feathers. Externally it measures 2¹⁄₄ inches in height and 3 by 3¹⁄₂ inches in diameter; the cup is 2 inches in diameter and about 1¹⁄₂ inches deep.

Of nestings in Maine, Knight (1908) says: “As soon as nest building begins, the favorite locality selected is a thicket of evergreen trees near the highway, some open pasture containing a few clumps of scattered evergreens, small thickets of evergreens along the banks of some stream or river or about the shore of a pond or lake, or a row of trees about some country dwelling or in an orchard. In the vast majority of cases an evergreen tree is selected as a nesting site, though occasionally some hardwood tree, such as maple, apple or birch, may be taken. A majority of nests seem to be placed in cedar trees, with fir and spruce following as close second choices.”

Forbush (1929) mentions two Massachusetts nests in tall white pines. A nest studied by Mrs. Nice (1930a), at Pelham, Mass., was “six feet up in a small red cedar on a branch next to the trunk. It was a rather shallow affair, composed of cedar twigs and bark, plant fibers, a piece of string and pine needles, and was lined with a few horse hairs and many Ruffed Grouse feathers.”

Dr. Paul Harrington has sent me his notes based on the study of 44 nests of the myrtle warbler in Simcoe County, Ontario. He says that the white pine is generally chosen as a nesting tree, the nests being placed from 6 to 40 feet up, averaging 15 feet; “28 nests were built on horizontal limbs about two-thirds out from the trunk, but none at the outermost end. They were conspicuous from below but not from above, as clumps of needles overhung them in such a way as to afford good protection.” Of the remainder, 2 were built in the top clump of needles in young trees; 5 were in small spruces, the lowest 3 feet, the highest 15, and all on horizontal limbs, 3 near the trunk and 2 halfway out on the limb; 5 were about 15 feet up in crotches of small cedars; 3 were found in red pines, in the outermost clumps of needles 10 to 15 feet from the ground; and 1 nest was 6 feet up in a small balsam. He says that the nest is lined thickly with feathers and a few hairs. “The feathers are so placed that, as well as lining the nest, they form a screen over the inside when the bird is not sitting. This is done by the shafts of the feathers being woven or imbedded into the inside of the nest and the vane lying free.” At Petawa he found these birds nesting in small jack pines.

Dr. F. A. E. Starr, in his notes from northern Ontario, also says that any conifers are suitable nesting sites: “I have found only one exception to the use of a conifer. This nest was built in a hawthorn, and when I collected the nest, the birds moved to a cedar.” A. D. Henderson writes to me: “The myrtle warbler is a fairly numerous summer resident at Belvedere, Alberta, and in the Fort Assiniboine District. It nests mainly in the muskegs in tamarack and spruce trees, but occasionally in deciduous trees close to a muskeg.” The nests are mostly from 10 to 15 feet up. One nest was in a jack pine, “in a bunchy growth at the end of a limb.” Baird, Brewer, and Ridgway (1874) state that MacFarlane found nests on the ground in the Anderson River region.

Eggs.—Most observers agree that four or five eggs form the usual set for the myrtle warbler. Tufts (MS.) says that "five eggs are more commonly found than four.” Dr. Starr says in his notes that “four eggs are rarely laid, two and three being the usual numbers, while sometimes only one is laid, along with those of the cowbird.” This is probably an abnormal situation in which the cowbird fills the nest with its own eggs, leaving little room for those of the warbler.

The eggs are ovate to short ovate and slightly glossy. The ground color is creamy white and is speckled, spotted, or blotched with “auburn,” “argus brown,” “Brussels brown,” “chestnut brown,” or “cinnamon-brown,” with undermarks of “light brownish drab,” “vinaceous gray,” or “purplish gray.” Generally the spots are concentrated at the large end, forming a wreath, but some are marked all over and may also have a few scrawls of blackish brown. I think the handsomest are those having the rich creamy white ground almost immaculate except for a solid wreath, around the large end, of spots and blotches of the browns overlapping and intermingled with the undertones of gray, so that they resemble somewhat the eggs of the wood pewee. On lightly marked eggs the drab or gray spots are the most prominent. The measurements of 50 eggs average 17.5 by 13.3 millimeters; the eggs showing the four extremes measure 20.3 by 13.2, 17.9 by 14.8, 14.8 by 12.9, and 16.0 by 12.4 millimeters (Harris).

Young.—The incubation period for the myrtle warbler is from 12 to 13 days and the young remain in the nest normally from 12 to 14 days. Incubating the eggs and brooding the young is apparently done entirely by the female, but both parents are active in feeding the young and in cleaning the nest. Mrs. Nice (1930a), with the help of Miss Lucille Baker, watched a nest containing young for a total of 19 hours, over a period of 6 days. On the first day the female brooded 25 percent of the time, but less later on; the brooding periods averaged 9 minutes.

A great deal of her energy was expended in delousing the nest—thirty-six minutes on July 28 and seventy-four minutes during the forenoon of the next day, but after that there was little trouble. Once, during thirteen minutes she made over 250 captures, all of which she ate. * * *

The male brought food sixty times, the female forty-eight times, so that the young were fed once in 10.9 minutes. About one-third of the time the male brought two insects, while the female did so on about one-sixth of her trips. During the fourteen hours of observation, the male brought food once In every nineteen minutes, the female once in every twenty-eight minutes. During the last five and one-half hours, the male brought food once in twenty-two minutes, the female once In eighteen minutes. * * *

Excreta were eaten by the female through July 29, but she carried one away at 7:05 P. M., July 28. She ate twelve sacs and carried eleven; her mate carried twenty-five and ate one. * * * He picked lice off his legs and gave them to the babies.

Mr. Knight (1908) says: “The female does most of the work of incubation, but on very rare and exceptional occasions I have found the male bird incubating and even engaged in song while on the nest. * * * The natal down rapidly dries and fluffs out on the young birds and is sepia-brown in color. At the end of six to seven days pin feathers begin to appear, and by the twelfth to fourteenth day the young are well advanced in their juvenal plumage and able to scramble out of the nest. Two to three days after leaving the nest they are able to essay short flights.”

Plumages.—Mr. Knight (1908) refers to the natal down as sepia-brown. Dr. Dwight (1900) describes the juvenal plumage, in which the sexes are alike, as “above, the feathers centrally dull black, edged with drab and buffy brown, producing a streaked effect. Below, much whiter but similarly streaked, a tinge of pale primrose-yellow on the abdomen. Wings and tail dull black, edged with drab, palest on primaries and outer rectrices. Two very indistinct buffy white wing bands. Upper and lower eyelids with dull white spots.”

The first winter plumage is acquired by a partial postjuvenal molt in August, which involves the contour plumage and the wing coverts, but not the rest of the wings or the tail. This plumage is entirely different from the juvenal and the sexes are only slightly differentiated. Dr. Dwight (1900) describes the young male as “above, sepia-brown, grayer on the back and obscurely streaked with black, the rump and a concealed crown spot lemon-yellow, the upper tail coverts black, broadly edged with plumbeous gray. Wing coverts black, plumbeous edged and tipped with white tinged with wood-brown forming two wing bands. Below, dull white, washed with pale buff on the throat and sides and obscurely streaked on the breast and sides with black, veiled by whitish edgings. Sides of breast with dull yellow patches. Incomplete orbital ring and faintly indicated superciliary stripe white or buffy.” He says of the young female: “The black streaking of this dress is less obvious both above and below than in the male, the plumage everywhere is browner, and the crown patch very obscure.”

The extensive prenuptial molt begins early, usually in March, before the birds have left their winter quarters; a few new feathers may be assumed even in late February but most of the molt occurs in April while the birds are migrating; it is, however, generally completed by the time the birds have reached their breeding grounds. Dr. Dwight (1900) says this molt "involves most of the body plumage and wing coverts, occasionally a tertiary but not the rest of the wings nor the tail. The black and gray of the upper surface, the white wing bars and the yellow crown and rump are new, some of the old upper tail coverts and a part of the feathers of the abdomen and crissum being retained in many cases, those of the back and elsewhere less often. Young and old become practically indistinguishable although the young usually have browner and more worn wings and tails, obvious in the primary coverts, but the differences are not absolute.” In the female, “the first nuptial plumage is assumed by a restricted moult, leaving behind many brown feathers. The brown feathers of the lores and auriculars are assumed by moult.”

The adult winter plumage is acquired by a complete postnuptial molt, beginning late in July. In the male, this “differs little from the first winter dress, but the wings and tail are blacker with brighter gray edgings, noticeable especially in the primary coverts. The back is usually grayer and the lower parts whiter, with broader streakings above and below.” In the female there are similar differences, the adult winter female resembling the young male at that season. Adults have a complete postnuptial molt in July and a prenuptial molt as in the young birds.

Food.—Forbush (1929) sums up the food of this warbler very well as follows:

The Myrtle Warbler is one of the few warblers that can subsist for long periods upon berries and seeds, although undoubtedly it prefers insects when it can get them. Along the coast during the milder winters there are many flies rising from the seaweed in sheltered spots on mild days even in January, and there are eggs of plant-lice and some hibernating insects to be found on the trees, but the principal food of the Myrtle Warbler in New England during the inclement season is the bayberry. They can exist, however, on the berries of the Virginia juniper or red cedar and these seem to form their principal food when wintering in the interior; berries of the Virginia creeper or woodbine, those of viburnums, honeysuckle, mountain ash, poison ivy, spikenard and dogwoods also serve to eke out the birds’ bill of fare. In the maple sugar orchards in early spring they occasionally drink sweet sap from the trees. In the southern Atlantic states they take palmetto berries. North and south they also eat some seeds, particularly those of sunflower and goldenrod. During spring and summer they destroy thousands of caterpillars, small grubs and the larvae of saw-flies and various insects, leaf-beetles, dark-beetles, weevils, wood-borers, ants, scale insects, plant-lice and their eggs, including the woolly apple-tree aphis and the the common apple-leaf plant-louse, also grasshoppers and locusts, bugs, house-flies and other flies including caddice-flies, crane-flies, calcid-flies, ichneumon-flies and gnats, also spiders.

To the above comprehensive list there is little to be added, although wild cranberries and the berries of the poison sumac might have been included. Myrtle warblers are doubtless instrumental in spreading the seeds of poisonous species of Rhus, which is not to their credit; they also help to disseminate the red cedar, as they digest only the outer covering of these three and the bayberries. These warblers are often seen on the beaches and sand dunes eating the seeds of the beachgrass, or in open fields feeding on grass seed and doubtless various weed seeds. They frequent the fresh holes bored by sapsuckers to drink the flowing sap and eat the insects that are attracted to it. In Florida, in winter, they drink the juice of fallen oranges in the groves and even the broken oranges on the trees.

They are somewhat expert as flycatchers, taking mosquitoes and gnats in the air. Knight (1908) writes: “During the fall months they enter the city gardens and orchards, climb over the roofs and along the gutters of houses, peering into every nook and cranny. They hover on beating wings about such crannies of the clapboards and finish where they may have spied some delicious, big fat spider, chrysalis or other delectable morsel, and such finds are speedily devoured. Now peering, now hovering, and now springing into the air after some winged insect, they stop about a building for a few hours or days, slowly but surely retreating southward.”

Behavior.—Much of the behavior of this friendly little bird has been referred to in connection with its activities about our homes and gardens and its nesting habits. Tilford Moore tells me that “these birds seem to have a tendency toward ‘creeperism,’ in that they are often seen hanging to the bark of a vertical trunk or branch, and are usually on the larger branches rather than among the smaller twigs. They often flutter a lot when hanging to the bark.” And Wendell Taber sends me this note: “On May 5, 1940, Richard Stackpole and I watched a flock in West Newbury, Mass. The birds were running about on the grass near a stream. Again, they would alight at the base of a tree and run up it several feet. I think all the birds that performed this feat were females. They were most deceptive, and we kept thinking we were seeing brown creepers until we put field glasses on them.”

William Brewster (1938) writes of the behavior of a female about her nest, 35 feet from the ground in a hemlock: “The female Yellow-rump was sitting and for some time she absolutely refused to leave her eggs. Watrous first shook the branch and then with a long stick poked and shook smartly the twigs within an inch or two of her head. At length she hopped out of the nest and stood for a moment or more on its rim looking about her. Then she fluttered down towards the ground with quivering wings and wide spread tail, moving slowly and alighting several times on a branch or cluster of twigs where she would lie prostrate for a moment beating her wings feebly and simulating the movements of a wounded or otherwise disabled bird.”

Dr. Stone (1937) describes the flight of the myrtle warbler very well:

We soon learn to identify their rather jerky flight as they rise from the bushes, and with a series of short wing flips turn now to the right, now to the left, in their zigzag progress, rising somewhat with the beats, and falling in the intervals. Sometimes a bird will go but a short distance, flitting from bush to bush, while others will climb higher and higher in the air, drifting in their jerky way across the sky like wind-blown leaves. * * *

As soon as a Myrtlebird alights on a bush there is a short, sharp flip of tin tail, not a seesaw action, but one involving the body as well, and as it comes to rest the head is drawn in and the plumage ruffled up making the outline more nearly globular, while the wings are dropped slightly so that their tips are a little below the base of the tail.

Francis H. Allen has sent me the following notes on the behavior of this species: “Aug. 27, 1915, Mt. Sunapee, N. H. On the summit of the mountain an immature myrtle warbler, very tame, flitted and hopped about on the ground, over moss and rocks, and in bushes and trees, feeding industriously on small insects. It seemed to pay no attention to my companion and me, and at one time hopped between us when we stood about 6 feet apart, and came within 2 feet of my outstretched hand as I held a crumb out towards it. I followed it about a little and found it quite fearless, except when I made a sudden movement. The bird could fly well and seemed perfectly well able to take care of itself.

“July 5, 1931, Mt. Whiteface, N. H. One or more were seen flying up fifty or a hundred feet above the tops of the low spruces and darting about up there after insects—doubtless the black flies which were abundant on the summit.

“Oct. 25, 1941, Plymouth, Mass. A sizable flock were feeding actively, flying back and forth across the narrow Eel River, feeding among foliage, catching flies and eating bayberries. One came within 6 feet of me and calmly ate bayberry after bayberry.”

Voice.—Aretas A. Saunders contributes the following account of the songs: “The songs of the myrtle warbler show some differences from those heard from birds on migration or on the breeding grounds. The song in general is a series of short, rapid notes in a rather colorless simple, but musical quality. The number of notes, in my 41 records, varies from 7 to 21 and averages about 12. The songs heard on migration, however, average 11 while those on the breeding grounds average 14.

“The songs heard on migration are quite indefinite in form; the pitch rises and falls irregularly, and no two songs are much alike. An individual bird may sing many variations, each song it sings often being a little different from the others. The notes, however, are all about the same length and loudness, accented notes that stand out from the others being rare. This song shows indications of a somewhat primitive character.

“The song on the breeding grounds is somewhat more definite; the notes are often joined in 2-note phrases, the first note of each phrase higher in pitch than the second and each phrase successively higher, so that the song trends upward in pitch. This is true of 10 of my 13 records of the song on the breeding grounds in the Adirondacks. The other 3 have a slight downward trend. In addition to the more regular form, these songs have a somewhat brighter, livelier, and more musical sound than those heard on migration.

“Songs of this species vary from 1 to 2⁴⁄₅ seconds in length. There are usually about seven notes per second. Only 3 of my records show any irregularity in the time of the notes, that is having some notes that are shorter or longer than the others. Pitch of the songs varies from F‴ to E‴´, a half tone less than an octave. Single songs vary from one to four and a half tones, averaging about two and a half tones; only 5 records are greater in range, and only 16 are less, nearly half of the records having the average range.

“Since the myrtle warbler winters in Connecticut, I am able to get the first dates of singing. In 30 years of records the average date is April 13; the earliest April 2, 1923, and the latest April 25, 1920. In the Adirondacks the last date of singing noted was July 31, 1926.

“The call-note, tchick, is louder than in most warblers. I found it pitched on D″. Another note is a fainter tseet tseet, usually doubled and pitched on F-sharp‴.”

Francis H. Allen (MS.) describes the song in a different way as follows:

“The only syllabifications I find in my notes are of a bird heard at West Bridgewater, Vt., June 19, 1907, which sang whee whee whee whee whee whee whee whee hew hew, sometimes with three or even four hews at the end and sometimes with only one; and one of a bird at South Tamworth, N. H., July 23, 1942, whose song consisted of two trills, ching ching ching ching ching weedle weedle weet.

“The ordinary call-note is a hoarse chep, easily distinguished from the call of any other New England warbler. I have also heard occasionally a slight tsip or tsit, suggesting a chickadee. The feeding call of the young out of the nest is a rapid succession of several explosive chips or pits with a rolling quality—a sort of chatter or chippering.”

On June 7, 1900, in Washington County, Maine, I recorded the song of the myrtle warbler as wheedle wheedle wheedle wheedle wheedle, repeated five to seven times so rapidly as to be hard to count and all on one key, usually ending abruptly but occasionally in a little trill.

Few writers have accorded the song of the myrtle warbler much praise, but Bradford Torrey (1885) pays it this tribute: “For music to be heard constantly, right under one’s window, it could scarcely be improved: sweet, brief, and remarkably unobstrusive, without sharpness or emphasis; a trill not altogether unlike the pine-creeping warbler’s, but less matter-of-fact and business-like. I used to listen to it before I rose in the morning, and it was to be heard at intervals all day long.”

Field marks.—The male myrtle warbler in spring plumage is easily recognized at a considerable distance in its blue-gray, black, and white plumage, offset by conspicuous patches of bright yellow on rump, sides, and crown, and by the black sides and cheeks. The female is much duller and browner, the yellow being less conspicuous and the black cheeks lacking. Young birds and fall adults are much like the female, but the yellow rump, showing plainly as the bird flies away from the observer, will distinguish the species at any season or age.

Enemies.—So much of the breeding range of the myrtle warbler is beyond the normal breeding range of the cowbirds that, until recently, it was supposed to be largely free from the imposition of this parasite. When Dr. Friedmann (1929) published his book on the cowbirds he had only three records of such molestation, but more have turned up since, particularly in the Middle West where the ranges of the two species overlap considerably. Dr. Paul Harrington writes to me from Toronto: “Sixty-five percent of the nests examined contained eggs or young of the cowbird; it would not be exaggerating to say that two-thirds of the initial nests are parasitized. The egg or eggs of the cowbird are often deposited before the nest is completed, leading to many a deserted nest. Twice I have found a cowbird’s egg imbedded, as so often happens in the yellow warbler’s nest, but in both cases yet another was in the nest with the owner’s. Twelve percent of the nests with eggs of the cowbird were deserted, but none in which the owner’s eggs were also present. Generally but one of the parasite’s eggs was found, occasionally two and rarely three.”

Dr. F. A. E. Starr says in his notes from Ontario: “Occasionally, when a cowbird usurps a nest, the birds continue building till the cowbird’s egg is imbedded. This is all in vain, however, as out of 30 nests, I have yet to find one which did not contain from one to three eggs of the cowbird.” And A. D. Henderson mentions in his notes from Belvedere, Alberta, a nest that held five eggs of the myrtle warbler and one egg of the Nevada cowbird, and another nestful consisting of four eggs of the warbler and two of the cowbird. Probably very few young of the warbler are likely to survive in nests with young cowbirds, which means that this parasite must seriously interfere with the normal increase in the warbler population.

Harold S. Peters (1936) lists two lice, two flies, and two mites as external parasites on the myrtle warbler.

Fall.—The myrtle warbler is one of the latest of its family to move southward and is also one of the most leisurely in migration; the migration covers practically the whole of September and October and much of November, the earliest arrivals sometimes reaching the Gulf States before the last ones have left Canada. Abundant in the spring, it is much more so in the fall, when it can often be seen in enormous numbers. As the birds drift along southward, many stop along the way where food is abundant and some spend the winter at no great distance from the southern limits of the breeding range. In Massachusetts, we usually look for them during the latter half of September or during those golden October days when woods are ablaze with the gorgeous autumn colors. As we stroll along the sunny side of the woods on some bright morning after a frosty night, the air is full of pleasing bird music. The robins, now wild woodland birds, are twittering or uttering their wild autumn calls as they drift through the trees; the white-throated and the song sparrows, from the brushy thickets below, give forth their faint, sweet notes like soft echoes of their springtime songs; and the myrtle warblers mingle their distinctive call-notes with these other voices as they glean for aphids on the birches. In the open grassy fields and weed patches, too, we find many myrtle warblers associated with the scattered flocks of juncos and field and chipping sparrows, feeding on the ground. And later in the fall, we find them in the bayberry patches near the seacoast, or even on the salt marshes or among the sand dunes with the Ipswich and savanna sparrows.

Southward along the Atlantic coast the flight is heavy; Dr. Stone (1937) says that, at Cape May, N. J., “on October 13, 1913, Julian Potter encountered a great flight of Myrtle Warblers which he estimated at 3,000. * * * October 31, 1920, was a characteristic Myrtle Warbler day. All day long they were present in abundance. The air seemed full of them wherever one went. Thousands were flittering here and there in the dense growth of rusty Indian grass (Andropogon), in the bayberry thickets, in pine woods and in dune thickets.”

From their breeding grounds in the northern interior these warblers continue to drift southward during October, not in compact flocks but straggling in a continuous stream, some alighting while others are moving on. In Ohio, according to Trautman (1940), “the numbers continued to increase rapidly until approximately October 5. Between October 5 and 20 the species was more numerous over the entire land area than it was at any other season, and thousands were daily present. It was particularly abundant on Cranberry Island, where it fed upon insects, cranberries, poison sumac, and other berries. On several occasions an estimated number between 1000 and 1200 individuals was seen within an hour on this island. After October 20 there was a rather gradual decline in numbers. By November 1, comparatively few remained, and in some years the birds had disappeared.”

Winter.—The myrtle warbler winters abundantly throughout the southern half of the United States east of the Great Plains, commonly as far north as southeastern Kansas, southern Illinois, southern Indiana and northern New Jersey, and less commonly or rarely and irregularly farther north. It is the only one of the wood warblers that is hardy enough to brave the rigors of our northern winters amid ice and snow and sometimes zero temperatures.

Robert Ridgway (1889) writing of its winter habits in southern Illinois, says:

It may often be sees in midwinter, when the ground is covered with snow, in the door-yards along with Snowbirds (Junco hyemalis), Tree Sparrows, and other familiar species, gleaning bread crumbs from the door-steps, or hunting for spiders or other insect tidbits in the nooks of the garden fence or the crevices in the bark of trees; and at evening, flying in considerable companies, to the sheltering branches of the thickest tree tops (preferably evergreens), where they pass the night. Not infrequently, however, they roost in odd nooks and crannies about the buildings, or even in holes in the straw- or hay-stacks, in the barn-yard. A favorite food of this species are the berries of the Poison-vine (Rhus toxicodendron), and during the early part of winter large numbers of them may be seen wherever vines of this species are abundant.

What few myrtle warblers remain in southern Massachusetts are usually to be found in situations similar to those frequented in late fall, especially near the coast where there is a good supply of bayberries and other berries. When this supply is exhausted they move elsewhere, though they can subsist to some extent on the seeds of the pitch pine, on grass seed, and on various weed seeds. In New Jersey, they are found in similar situations. Farther south they are abundant inland as well as on the coast, living in all kinds of environments—old fields, cultivated lands, thickets, brushy borders of the woodlands, and in woods of scrub oaks and pine. They are common to abundant on both coasts of Florida and in the interior and often come into the orange groves, to feed on the fallen oranges. A. H. Howell (1932) says: “Not infrequently they may be found in numbers on the Gulf beaches, or in reeds in the salt marshes of the coast or in the Everglades. They are partial to the borders of streams or sloughs, and sometimes venture out on the floating vegetation in rivers or lakes.”

The following is contributed by Dr. Alexander F. Skutch: “In December, 1932, it was vividly brought home to me how widely the myrtle warblers are spread over the earth during the winter months, and in what varied climates they dwell. On the ninth, a clear, cold, winter day, I met a small party of these yellow-rumped birds in a barren field at the edge of a woods in Maryland. On the twenty-fourth, I watched them fly above the tatters of melting snow in New Jersey, within view of the skyscrapers of New York. That afternoon I embarked upon a ship, and a week later arrived upon a banana plantation in Guatemala, where the air was balmy and the landscape vividly green, where snow and bleak winds seemed to belong to another world. Yet here, too, were myrtle warblers, hundreds of them, feeding in the open pastures and along the roadways, wherever the vegetation was not too dense, then rising up in compact flocks, wheeling and dropping together, moving always as though actuated by a true group spirit. During three days on that plantation, I met 23 kinds of winter visitants from the North; yet the myrtle warbler appeared to be the most abundant of them all: certainly, I saw far more of them than of any other migratory bird; yet this was in part because they foraged in more exposed places. Of all the warblers I found here, this was the only species that moved in flocks; for most of the wood warblers that winter in the Central American lowlands are strict individualists. It is also significant that of all the 23 species of wintering birds, this, the most abundant in December, was the only one then common that I had not recorded from February to June of the same year, when I passed 4 months studying the birds on that same plantation.

“Although it has been recorded from Central American localities as early as October and as late as April, the myrtle warbler is certainly most abundant as a winter visitant from November to March. All my own records from points in Guatemala, Honduras, and Costa Rica fall within these 5 months. It arrives later and departs earlier than warblers less tolerant of cold.

“The myrtle warbler winters in a variety of situations. At Puerto Castilla, on the northern coast of Honduras, I found these warblers abundant at the end of January, 1931. Here they foraged upon the lawns between the cottages, hopping rather than walking like water-thrushes, and when alarmed flew up to rest upon the broad fronds of the coconut palms that lined the sandy beach. At the other extreme, I have found them in mountain pastures, rarely as high as 8,500 feet above sea level. In the highlands, this bird is likely to be confused with the Audubon warbler, from the mountains of western United States, in similar dull winter attire. But the Audubon warbler, even at this season, wears five patches of yellow—on the crown, throat, both sides and rump—while the myrtle warbler shows only four, lacking that on the throat. The presence or absence of yellow on the throat is a distinguishing feature.

“At the end of December, 1937, I found myrtle warblers abundant in the vicinity of Buenos Aires de Osa, a hamlet in the lower Térraba Valley of Costa Rica, of interest to the bird-watcher because, although lying in a region covered by the heaviest lowland forest, it is surrounded by extensive open savannas which support a rather different bird-life. Here fork-tailed flycatchers were also abundant, roosting by night in some orange trees behind the padre’s house, by day spreading in small flocks over the savannas, where they perched in the low bushes, only a few feet above the ground, and darted down to snatch up the insects they descried. It was surprising to find the myrtle warblers associating intimately with the flycatchers; just as, in the Guatemalan highlands, I had found Audubon’s warblers flocking with bluebirds. The myrtle warblers not only foraged about the bushes which served the flycatchers as watch-towers; but the two kinds of birds, so dissimilar in size and habits, changed their feeding grounds together. While I sometimes found the warblers alone, I saw them in company with the fork-tailed flycatchers too often for the association to be looked upon as accidental. I could not discover that either warbler or flycatcher derived any material advantage from the presence of the other. It seemed to be a case of pure socialibility.

“Central American dates are: Guatemala—Motagua Valley, near Los Amates, December 31, 1932; Sierra de Tecpán, March 16, 1933; Finca Mocá, January 20-26, 1935; Nebaj (Griscom), April 27; La Primavera (Griscom), April 8. Honduras—Puerto Castilla, January 27, 1931; Tela (Peters), March 17. Costa Rica—Vara Blanca, December 13, 1937, to February 28, 1938; Guayabo (Ridgway and Zeledón), March 18; Carrillo (Underwood), October 2; Guacimo (Carriker), December 4; Las Cañas, Guanacaste, November 21, 1936; El General, January 12, 1936; Buenos Aires de Osa, December 24-30, 1937.”

DISTRIBUTION

Range.—North America.

Breeding range.—The myrtle warbler breeds north to northern Alaska (Kobuk River and timberline on the south slope of the Brooks Range); northern Yukon (La Pierre House); northern Mackenzie (Aklavik; Fort Anderson; MacTavish Bay, Bear Lake; Lake Hardisty, and Artillery Lake); northern Manitoba (Lac du Brochet, Cochrane River, and Churchill); northern Ontario (Moose Factory); southern Labrador (Grand Falls and Rigolet, possibly Nain and Okkak). East to eastern Labrador (Rigolet and Cartwright); Newfoundland (St. Anthony, Canada Bay, and St. John’s); and Nova Scotia (Cape Breton Island, Sable Island, Halifax, and Yarmouth). South to southern Nova Scotia (Yarmouth); New Brunswick (Grand Manan); southern Maine (Gouldsboro, Deer Isle, Bath, and Auburn); New Hampshire (Concord); central and southern Massachusetts (Marlboro, Webster, and Pelham); southwestern Vermont (Bennington); northern New York (Falls Pond and Buffalo); rarely northeastern Pennsylvania (Pocono Lake); accidentally in northern Maryland (Havre de Grace); southern Ontario (London and Sarnia); northern Michigan (Crawford County and Douglas Lake); northern Wisconsin (Antigo, probably, Trout Lake, Namekagon Lake, and Superior); central Minnesota (St. Cloud, Brainerd, and Bemidji); southern Manitoba (Winnipeg and Aweme); central Saskatchewan (Flotten Lake and Prince Albert); central Alberta (Flagstaff, Camrose, Lobstick River, and Wipiti River); northern British Columbia (Fort St. John, Ingenika River, and Buckley Lake); and southern Alaska (Admiralty Island, Sitka, Seldovia, and Nushagak). West to western Alaska (Nushagak, Russian Mission, St. Michael, and the Kobuk River).

Winter range.—The myrtle warbler winters in two discontinuous areas. The principal winter home is north to central Oklahoma (Oklahoma City); northern Arkansas (Winslow, Little Rock, and Helena); western Tennessee (Memphis); southern Illinois (Anna and Mount Carmel); southern Kentucky (Bowling Green); central Virginia (Lexington); District of Columbia (Washington); southeastern Pennsylvania (Philadelphia); northern New Jersey (Morristown and Elizabeth); southern Connecticut (New Haven); Rhode Island (Providence); and northeastern Massachusetts (Cape Ann). It also occurs in winter irregularly north to Holly, Colo.; Hays and Manhattan, Kan.; Madison, Wis.; Chicago, Ill.; Battle Creek and Rochester (one banded in January), Mich.; Rochester, N. Y.; and Portland, Maine. East to Massachusetts (Cape Ann) and along the Atlantic coast to Florida (Miami and Key West); the Bahama Islands (Little Abaco and Caicos); Dominican Republic (Puerto Plato and Sánchez); Puerto Rico (San Juan); St. Croix Island; and rarely, Antigua. South to Antigua, northern Colombia, rare or accidental (Santa Marta region); and Panamá (Pearl Islands). West to Panamá (Pearl Islands, Canal Zone, and Almirante); Costa Rica (El General and Guayabo); eastern Nicaragua (Greytown and the Río Escondido); northern Honduras (Puerto Castilla and Lancetilla); western Guatemala (Dueñas and Tecpán); eastern Oaxaca (Tehuantepec); Veracruz (Orizaba); Tamaulipas (Victoria); Nuevo León (Monterrey); southwestern Texas (mouth of the Pecos River, Camp Barkeley, Taylor County, and Fort Worth); and central Oklahoma (Oklahoma City).

The western winter range is north to central Western Oregon (Newport and Albany). East to western Oregon (Albany); central California (Marysville, Stockton, Mariposa County, Redlands, and Potholes); southern Arizona (Tucson and Tombstone); and southwestern Sonora (Guaymas). South to southern Sonora. West to western Sonora (Guaymas and the Colorado River delta); western California (San Clementi Island, Santa Barbara, San Francisco Bay region, and Eureka); and western Oregon (Coss Bay and Newport).

The species as outlined is divided into two subspecies or geographic races. The Alaska myrtle warbler (D. c. hooveri) breeds from western Alaska and northwestern Mackenzie to central Alberta and central British Columbia; the eastern myrtle warbler (D. c. coronata) from western Saskatchewan eastward.

Migration.—Late dates of spring departure from the winter home are: Costa Rica—Guayabo, March 18. El Salvador—Volcán de San Miguel, March 22. Guatemala—Nebaj, April 27. Honduras—Lancetilla, March 17. Mexico—Valles, San Luis Potosí, May 2. Puerto Rico—Mayagüez, April 8. Haiti—Port-au-Prince, April 27. Cuba—Habana, April 28. Bahamas—New Providence, April 2. Florida—Pensacola, May 13. Alabama—Birmingham, May 8. Georgia—Atlanta, May 20. South Carolina—Greenwood, May 12. Louisiana—Mansfield, May 2. Mississippi—Oxford, May 8. Tennessee—Nashville, May 17. Arkansas—Helena, May 18. Texas—Bonham, May 6. Oklahoma—Norman, May 3.

Early dates of spring arrival are: New York—New York, April 1. Massachusetts—Lynn, April 11. Vermont—St. Johnsbury, April 12. Maine—Portland, April 6. New Brunswick—Scotch Lake, April 11. Nova Scotia—Yarmouth, April 11. Quebec—Hatley, April 22. Newfoundland—St. Anthony, April 25. Labrador—Cartwright, May 24. Illinois—Chicago, March 24. Indiana—Bloomington, March 26. Ohio—Youngstown, April 1. Ontario—Harrow, April 3. Michigan—Sault Ste. Marie, April 9. Missouri—Columbia, March 27. Iowa—Sigourney, April 3. Wisconsin—New London, April 1. Minnesota—Minneapolis, April 4. Kansas—Independence, April 7. Nebraska—Red Cloud, April 1. South Dakota—Brookings, April 7. North Dakota—Fargo, April 13. Manitoba—Aweme, April 12. Saskatchewan—Eastend, April 22. Mackenzie—Simpson, May 7. New Mexico—San Antonio, April 18. Colorado—Colorado Springs, April 17. Wyoming—Laramie, April 15. Montana—Kirby, April 29. Alberta—Glenevis, April 14. Washington—Seattle, March 14. British Columbia—Courtenay, March 31; Atlin, April 21. Yukon—Sheldon Lake, April 26. Alaska—Wrangell, April 29; Fairbanks, May 7.

Late dates of spring departure of transients are: District of Columbia—Washington, June 1. Pennsylvania—Warren, June 6. Illinois—Chicago, June 3. Indiana—Waterloo, June 3. Ohio—Oberlin, May 31. Missouri—Concordia, May 25. Iowa—Grinnell, June 1. Nebraska—Nenzel, May 27. North Dakota—Argusville, May 30. California—Red Bluff, May 3. Nevada—Quinn River Crossing, May 21. Washington—Tacoma, May 3.

Late dates of fall departure are: British Columbia—Atlin, September 19; Courtenay, October 14. Mackenzie—Nahami River, October 25. Wyoming—Laramie, November 25. Saskatchewan—Yorkton, October 14. Manitoba—Brandon, October 31. North Dakota—Argusville, November 15. South Dakota—Faulkton, November 15. Kansas—Lawrence, November 12. Minnesota—St. Paul, November 5. Wisconsin—Racine, November 16. Iowa—Wall Lake, November 15. Missouri—Kansas City, November 16. Illinois—Murphysboro, November 21. Michigan—Detroit, November 19. Indiana—Indianapolis, November 20. Ontario—Point Pelee, November 23. Ohio—Toledo, November 17. Newfoundland—Tompkins, October 4. Prince Edward Island—North River, October 15. Quebec—Kamouraska, November 9. New Brunswick—Saint John, November 4. Maine—Portland, November 9. New Hampshire—Durham, November 4. Massachusetts—Boston, November 27. New York—Brooklyn, November 22. Pennsylvania—Doylestown, November 29.

Early dates of fall arrival are: Washington—Bellingham, September 28. Oregon—Thurston, October 5. California—Eureka, October 12. Wyoming—Yellowstone Park, August 25. North Dakota—Fargo, September 8. South Dakota—September 15. Nebraska—Fairbury, September 30. Kansas—Lawrence, September 26. Oklahoma—Oklahoma City, October 12. Texas—Somerset, October 10. Iowa—Grinnell, September 6. Missouri—St Louis, September 17. Illinois—Chicago, August 31. Indiana—Hobart, September 2. Ohio—Austinburg, August 25. Kentucky—Bowling Green, September 14. Tennessee—Athens, October 3. Arkansas—Rogers, October 4. Louisiana—Monroe, September 26. Mississippi—Edwards, September 22. New York—Rhinebeck, August 31. Pennsylvania—Pittsburgh, September 8. District of Columbia—Washington, September 9. West Virginia—Bluefield, September 12. Virginia—Naruna, September 22. North Carolina—Mount Mitchell, September 30. South Carolina—Spartanburg, September 21. Georgia—Round Oak, October 10. Alabama—Anniston, October 8. Florida—New Smyrna, October 4. Bahamas—Cay Lobos, November 22. Cuba—Habana, November 17. Dominican Republic—San Juan, October 1. Puerto Rico—Mayagüez, December 14. Costa Rica—Carrillo, October 2.

Banding.—The myrtle warbler comes rather more readily than other warblers to banding traps, especially in winter, and so has yielded several records of migration and of longevity for return to the place of banding. A myrtle warbler banded at Elmhurst, Long Island, on October 19, 1936, was recovered on December 9, 1936, at Awensdaw, S. C. One banded on October 2, 1932, at Fargo, N. D., was found dead December 5, 1932, at Clarence, La. Another banded at Wilton, N. D., on September 25, 1939, was found in January 1940 at Leola, Ark. One banded on February 2, 1930, at Gastonia, N. C., was shot on December 25, 1930, at Kings Creek, Cherokee County, S. C.

A banding station at Thomasville, Ga., obtained several records indicative of the birds’ tendency to return to the same wintering place. Three birds banded in March 1920, were retrapped in February and March of 1921. One banded February 24, 1921, was retrapped February 5, 12, and 13, 1924, and found dead, apparently of starvation, on the fifteenth. A myrtle warbler banded on February 28, 1917, was retrapped in March 1920 and several times between March 1 and 17, 1921. It was then at least 5 years old and had made four round trips to the breeding grounds.

Another myrtle warbler banded at Huntington, Long Island, on October 23, 1933, was killed February 1, 1940, at Dunbar, S. C.; it was then at least 6¹⁄₂ years old.

Casual records.—At least six specimens of the myrtle warbler have been collected in Greenland: Fiskenaes, May 21, 1841; Julianehaab, about 1847; Godhavn, July 31, 1878; Nanortalik, May 23, 1880; Agpamiut, in Sukkertoppen District, October 15, 1931; and Kangea, near Godthaab, October 28, 1937. A specimen was taken from the stomach of a white gyrfalcon October 7, 1929, killed near the Post on Southampton Island. Two specimens have been collected on the Arctic Coast of Alaska: one on June 3, 1898, at Point Tangent; and one June 4, 1930, near Point Barrow. A myrtle warbler was collected May 25, 1879, on the northeast coast of Siberia at latitude 67° N. At sea about 100 miles from Cape Hatteras, several myrtle warblers were noted on October 16 and 31, 1930.

Egg dates.—Maine: 16 records, May 26 to June 23; 10 records, June 11 to 20, indicating the height of the season.

New Brunswick: 10 records, June 5 to 28; 6 records, June 13 to 21.

Nova Scotia: 14 records, May 23 to June 21; 7 records, June 3 to 17 (Harris).

DENDROICA CORONATA HOOVERI McGregor

ALASKA MYRTLE WARBLER

HABITS

The Alaska myrtle warbler is another subspecies that was described many years ago but only recently admitted to the A. O. U. Check-List. Richard C. McGregor (1899) described this warbler, from specimens collected in California, as a western race and named it for his friend Theodore J. Hoover, who collected the type and placed his material at his disposal. He called it Dendroica coronata hooveri, Hoover’s warbler. In his description of it he says that it is “in colors and markings like Dendroica coronata, but with wing and tail much longer.” His table of measurements shows that the wings of California males average .15 inch longer than those of eastern birds, and the tails .14 inch longer, less than ¹⁄₆ inch! Among the wing measurements of eastern males the individual variation is as great as the difference in his averages, the shortest measuring 2.80 and the longest 2.95 inches! It appears to be a quite finely drawn subspecies.

Dr. Oberholser (1938) says of it: “The Myrtle Warblers breeding in Alaska are recognizable as a western race of this species. They differ from the eastern bird in larger size and more solidly black breast in the male. The upper parts in winter plumage and in the young are also less rufescent than in the eastern bird.”

The breeding range of this race, so far as known, extends from northwestern Mackenzie to western Alaska, and southward to central British Columbia and central Alberta. It has been found in winter from California to southeastern Louisiana, in the southeastern United States, and in northern Baja California and in southern Veracruz, in Mexico. It may be commoner than is supposed, as it is recognizable only with specimens in hand.

Dr. Joseph Grinnell (1900) writes of its habits in northern Alaska:

Hoover’s Warblers were numerous summer residents of the timber tracts throughout the Kowak Valley from the delta eastward. In the latter part of August scattering companies were frequenting the spruce, birch and cottonwoods, among the foliage of which they were constantly searching, with oft-repeated ‘chits,’ just as are their habits in winter in California. The last observed, a straggling flock of six or eight, were seen in a patch of tall willows about sunset of August 30th. The following spring the arrival of Hoover’s Warblers was on May 22nd. They were already in pairs and the males were in full song. At this season they were confined exclusively to the heavier spruce woods. In the Kowak delta, on the 23rd of June, a set of five considerably-incubated eggs was secured. The nest was in a small spruce in a tract of larger growth, and only four feet above the ground. It is a rather loose structure of fine dry grass-blades, lined with ptarmigan feathers.

In the Atlin region of northern British Columbia, according to Mr. Swarth (1926), it is a common species, breeding mostly in the lowlands:

A nest with five fresh eggs (Mus. Vert. Zool. no. 1992) was taken by Brooks on June 15. It was in a slender spruce, one of a small thicket in a locality that is largely poplar grown, about forty feet from the ground and near the top of the tree. It rested on the twigs forming the terminal forks of a branch, about three feet from the trunk. The outer walls of the nest were built mostly of the shredded bark of the fire-weed stalks, with a little fire-weed ‘cotton,’ some coarse grass and small twigs, and several wing and tail feathers of a small bird. In the lining there was some horse hair, mountain sheep hair and a few soft feathers.

Another nest, containing newly hatched young on June 28, was in a small jack pine in open woods on the shore of Lake Atlin.

During the last week in August and the first week in September the southward exodus was at its height. Flocks of warblers, mostly this species, flitted rapidly through the poplar woods, and there was a constant stream of myrtle warblers making long flights overhead. The last one, a single bird, was seen September 19.

As the breeding ranges of Hoover’s warbler and Audubon’s warbler approach each other in British Columbia and may even overlap it would not be strange if hybrids between these two closely related species should occasionally turn up. Joseph Mailliard (1937) calls attention to a number of such hybrids between both forms of coronata and auduboni. And more recently, Fred M. Packard writes to me: “I have inspected skins in most of the major museums in America to detect these hybrids, and have been surprised at the number I have found. All but two were taken in the Rockies or farther west, so that presumably the subspecies concerned is D. c. hooveri.”

DENDROICA AUDUBONI (Townsend)

PACIFIC AUDUBON’S WARBLER

Plate 34

HABITS

The Pacific Audubon’s warbler is a handsome western species closely related to our familiar myrtle warbler, which to a large extent it replaces, and is much like it in behavior and appearance; but it has one more touch of color in its brilliant yellow throat, five spots of yellow instead of four, and it has more white in the wings and tail. Although its breeding range does not extend nearly as far north as that of the myrtle warbler, it extends farther south, and to considerably higher altitudes, breeding largely in the Canadian Zone among the pines, firs, and spruces. Including the range of the Rocky Mountain form (memorabilis), which has not yet been admitted to the A. O. U. Check-List, the type race breeds from central British Columbia, central Alberta, and west-central Saskatchewan southward to southern California, northern Arizona, New Mexico, and western Texas. Throughout most of this range it is widely distributed in the lowlands only during the winter, retiring to the mountains for the breeding season.

In the mountains of New Mexico it has been found breeding at altitudes of from 7,500 feet to over 11,000 feet. In Colorado it breeds at similar elevations and perhaps up to nearly 12,000 feet. In southern California, Dr. Joseph Grinnell (1908) found it breeding in the San Bernardino Mountains from 9,000 feet “almost to timber limit, 10,500 feet elevation, at least. * * * This was one of the most abundant birds of the San Bernardino mountains, and was widely distributed from the lower edge of the Transition zone up through the Boreal.” Grinnell and Storer (1924) write:

The Audubon Warbler is the most widely distributed and the most abundant of all the species of wood warblers found in the Yosemite region. It occurs in numbers throughout the main forested districts of the mountains during the summer season, and it frequents the deciduous trees and brush of the foothill and valley country in the winter time.

Altitudinally its summer range extends from the beginning of the Transition Zone yellow pines on the west slope, at 3300 to 3500 feet, up through the lodgepole pines and other conifers of the Canadian and Hudsonian zones to the upper limit of unstunted trees at 10,000 feet or a little higher. * * *

During the summer season the Audubon Warbler keeps mainly to coniferous trees, foraging from 10 to 50 feet or more above the ground. In the Transition Zone and part of the Canadian Zone it shares this habitat with the Hermit Warbler, but at the higher altitudes it is the only warbler present in the evergreen forest.

Farther north, in Mono County, Calif., James B. Dixon tells me that he found it nesting between 7,600 and 9,500 feet elevation. Referring to the Toyabe region in Nevada, Dr. Jean M. Linsdale (1938) found the Rocky Mountain form in a somewhat different environment: “In the mountains the area occupied by this warbler agreed fairly well with the area covered with trees. Individuals were seen most often in aspens, limber pines, birches, willows, and mountain mahoganies.” Angus M. Woodbury (MS.) says of the breeding range of the Rocky Mountain form in Utah: “It summers in altitudes ranging from about 7,000 to 10,000 feet and nests in almost any of the components of the forests in those altitudes; pine, fir, spruce, aspen, or oak.”

In Washington, Audubon’s warbler is common and well distributed from near sea level in the vicinity of Seattle and Tacoma up to about 8,000 feet in the mountains. Near Tacoma, D. E. Brown showed us some typical lowland haunts of this warbler in the so-called “prairie region.” On this smooth, flat land, a fine growth of firs and cedars was scattered about in the open; the two or three local species of firs were most abundant and were growing to perfection, being well branched down to the ground.

Spring.—There is a northward as well as an altitudinal migration in the spring. Samuel F. Rathbun says in his notes from Seattle: “Although the Audubon’s is of frequent if not regular occurrence during the winter, a migration of the bird through the region is to be noted each spring and fall.” Near Seattle the first birds are seen and their song is heard about March 10 to 15, and numbers are seen passing through up to the latter part of April. “By way of comparison, in the Lake Crescent section the first are seen about April 2, at the earliest, and after three weeks the last appear to have passed by, as the species performs its spring migration in a leisurely manner.” A later wave of migrants passes through Seattle between April 10 and 25, probably birds that nest farther north.

Migration is evident in Utah, for Woodbury (MS.) says: “In addition to its summer residence, it is a common migrant through the state, and a sparse winter resident, mainly at low altitudes. It migrates through the streamside and cultivated trees of the valleys, including shade trees and orchards. The migrations cover a period of about 6 weeks each in spring and fall, usually from about mid-April to the end of May and from mid-September to the end of October, but in different years the waves may be a little earlier or later.”

In California, there is a gradual exodus of Audubon’s warblers from the lowlands to the mountains during April and May. Mrs. Amelia S. Allen tells me that “by the end of April they have disappeared from the San Francisco Bay region.” And Swarth (1926b) says that in May, following the spring molt, “there is a gradual withdrawal of the birds to the higher mountains and to more northern latitudes.”

Audubon’s warbler occurs abundantly on the Huachuca Mountains, Ariz., but as a migrant only, during March, April, and May. Swarth (1904) writes:

Though distributed over all parts of the mountains, they were at all times more abundant in the higher pine region, than elsewhere; and on April 24, 1903, I found them particularly numerous along the divide of the mountains, evidently migrating. They could hardly be said to be in flocks on this occasion, for along the ridge, which runs almost due north and south, there was for several miles a continuous stream of Audubon Warblers travelling rapidly from tree to tree, always moving in a northerly direction; sometimes a dozen or more in one pine, and sometimes only two or three, but never stopping long and all moving in the same direction. Almost all that were seen on this occasion were high plumaged males, hardly half a dozen females being observed for the day.

This was about two weeks before the local breeding race (D. a. nigrifrons) might be expected to arrive.

Dr. Merrill (1888), at Fort Klamath, Oreg., found Audubon’s warblers “extremely abundant during the migrations. A few males were seen at Modoc Point on the 8th and 9th of April, and at the Fort on the 15th; by the 20th they were quite plentiful. A second ‘wave’ composed of both males and females, which latter had not previously been seen, arrived about the 4th of May, when they suddenly became more abundant than ever, bringing D. aestiva morcomi and H. lutescens with them.”

Nesting.—The only two nests of Audubon’s warbler that I have seen were shown to me in Washington, near the State University at Seattle. The University is located on high land at the north end of Lake Washington, where the steep banks, sloping down to the lake, are heavily wooded with a mixed growth of large and small firs of at least two species, as well as cedars, alder trees, and maples. In the more open part of the woods I was shown, on April 29, 1911, a nest of this warbler placed about 30 feet from the ground on two small branches and against the trunk of a tall Douglas fir beside a woodland path. The other nest I saw in the previously described “prairie region” near Tacoma on May 14, 1911; it was placed only 9 feet from the ground but 10 feet out from the trunk of a dense Douglas fir growing in the open, and was well concealed in the thick foliage.

These nests were evidently typical for the region, according to Rathbun. He mentions in his notes two other nests. One, found May 2, 1909, on the east side of Lake Washington and along a road, was 30 feet from the ground in a small hemlock, near the extremity of one of the limbs and 7 feet out from the trunk. The other, found May 11, 1913, was in a small fir about 30 feet up and about 4 feet from the trunk on one of the lower limbs. “The nest is a very beautiful structure, constructed outwardly of very small twigs from the fir or hemlock, inside of which are placed smaller ones of the same character, with black rootlets, and lined with feathers, of which a quantity are used, and a few horsehairs. It is a compactly built affair.” Dawson and Bowles (1909) say that the nests are placed from 40 to 50 feet up, and usually measure 4 inches in width outside by 2³⁄₄ in depth; and inside 2 by 1¹⁄₂ inches. They are made externally of such materials as fir twigs, weed tops, flower pedicels, rootlets, and catkins, and are heavily lined with feathers of various birds—including grouse, ptarmigan or domestic fowls—these feathers often curving upward and inward so as partially to conceal the eggs.

Dr. J. C. Merrill (1898) found a very different type of nesting near Fort Sherman, Idaho: “Here a majority of the nests I found were in deciduous trees and bushes, generally but a few feet from the ground. One was in a small rose bush growing at the edge of a cut bank overhanging a road where wagons daily passed close to it. * * * Occasionally one was seen in deep woods by the roadside near where hay had been brushed off a load on a passing wagon; this was utilized for the entire nest except lining, making a conspicuous yellow object in the dark green fir or pine in which it was placed.”

P. M. Silloway (1901) found a nest of Audubon’s warbler near Flathead Lake, Mont., that was 18 feet from the ground in a fork of a willow. “The fork containing the nest was in a main stem, upright, a number of feet below the leaf-bearing part of the tree, so that the nest was exposed quite fairly to view.” H. D. Minot (1880) found one at Seven Lakes, Colo., in an odd situation: “The nest, composed of shreds and feathers, with a few twigs without and hairs within, was built in a dead, bare spruce, about twenty feet from the ground, compressed between the trunk and a piece of bark that was attached beneath and upheld above, where a bough ran through a knot-hole, so compressed that the hollow measures 2¹⁄₄ x 1³⁄₄, and 1¹⁄₂ inches deep.” Dr. Chapman (1907) describes a nest from Estes Park, Colo., as “loosely constructed of weed-stems and tops, and strips of bark, lined with fine weeds and horse-hair.”

Mr. Woodbury (MS.) describes Utah nests as “compactly woven, cup-shaped structures, usually of fine grasses, plant fibers or shredded bark, lined with feathers or some substitute, and camouflaged with some fine stringy material holding bracts or other small particles in place.” He reports nests in such conifers as spruce, balsam, and ponderosa pine, and in aspen and oak.

J. Stuart Rowley writes to me: “In California, I have found several nests of this species in the San Bernardino Mountains and in the Mono County area in the northern part of the State. The nests I have found have all been beautifully made structures, securely fastened to small, low hanging branches of lodgepole pine, and placed about 10 to 12 feet from the ground.”

Dr. Grinnell (1908) records three nests, found in the San Bernardinos; one “was twenty feet above the ground in the thick foliage of a short drooping fir bough. It was compactly composed of weathered grasses, frayed-out plant fibres, and tail and wing feathers of juncos and other small birds. Internally it was thickly lined with mountain quail feathers, some of the chestnut-colored ones sticking above the rim conspicuously. This feather feature seems to be characteristic of Audubon warblers’ nests, as it was noticeably present in all that we saw.” Another nest was 25 feet from the ground in one of the lowest branches of a yellow pine. The third “was snugly tucked away in a small clump of mistletoe on an alder branch twelve feet above the ground.”

J. K. Jensen (1923) says of New Mexico nests: “The nests are usually placed on a horizontal limb of a pine or spruce, but also among dead twigs on the trunks of cottonwoods, and even in a cavity of some tree. All nests found were lined with a few feathers of Bluebirds and Long-crested Jay.”

Nests in tamarack, cedar, and birch have been reported by other collectors.

Eggs.—Audubon’s warbler lays from 3 to 5 eggs, almost always 4. They are ovate, tending toward short ovate, and are slightly glossy. They are grayish or creamy white, spotted and blotched with “raw umber,” “Brussels brown,” “argus brown,” and sometimes “auburn,” with underlying spots of “pale brownish drab,” “light brownish drab,” or “light mouse gray.” The markings are often confined to the large end, and frequently the drab undertones are in the majority, sometimes running together to form a cap, and this is relieved with a few superimposed spots or blotches of dark “argus brown,” or scattered small scrawls so dark as to appear almost black. The eggs generally are sparsely but rather boldly marked. The measurements of 50 eggs average 17.6 by 13.5 millimeters; the eggs showing the four extremes measure 19.4 by 14.0, 19.1 by 14.5, and 15.4 by 12.3 millimeters (Harris).

Young.—The period of incubation is probably between 12 and 13 days, as with the Myrtle warbler. Mrs. Wheelock (1904) writes:

In the brood whose incubation was closely watched, I found that twelve days elapsed between the laying of the last egg and the advent of the young. The female did most of the brooding; the male was found on the nest only once, but was usually perched on a neighboring tree warbling his enthusiastic little song, “cheree-cheree-cheree-cheree.” After the young were feathered enough to leave the nest, which occurred when they were two weeks old, the male forgot to sing and became a veritable family drudge with the brood ever at his heels clamoring for food. * * * The pair whose young had hatched so early were very friendly, feeding them without much fear while I sat within three or four feet of the nest and on a level with it. They usually came with nothing to be seen in their beaks, but the insect food they had gleaned and carried in their own throats was regurgitated into the throats of the young. When the latter were five days old the mother bird, for the first time, brought an insect large enough to be seen, and crammed it into the open bill of one of the nestlings, and from that time on most of the food brought was eaten by the young while fresh.

The general opinion seems to be that two broods are often, perhaps usually, raised in a season. The young birds are the first to leave their mountain resorts, probably driven out by their parents, and are the first to appear in the lowlands.

Plumages.—The plumages and molts of Audubon’s warbler are similar in sequence to those of the myrtle warbler; in juvenal and first fall plumages the two species are almost indistinguishable, though there is always more white in the tail feathers of the western bird, in which the white spot usually reaches the fourth feather even in young birds. In any plumage the white areas in the tail of Audubon’s warbler occupy two more feathers on each side of the tail than in the myrtle warbler.

The juvenal Audubon’s warbler is brown above, streaked with black and white, and white below, streaked with black; the sexes are alike. This plumage is worn but a short time; Dr. Grinnell (1908) says that it “is of very short duration, not more than fifteen days, I should say”; and Swarth (1926) says that is “worn but a few weeks. Tail and wing have scarcely attained full length when the first winter plumage begins to appear, and by the time the birds are drifting back into the lowlands in September the last vestige of the juvenal plumage is gone.” This postjuvenal molt involves all the contour plumage and the wing coverts, but not the rest of the wings or the tail.

In the first winter plumage there is but slight difference between the sexes, the female being somewhat duller than the male and often with little or no yellow on the throat. In both sexes the plumage is browner throughout, the yellow areas are paler and less pronounced, the black streaks are less prominent, and the white areas in the tail are more restricted than in fall adults. Swarth continues: “All winter long these drab-colored birds pervade the lowlands, conspicuous only through force of numbers. Then, the latter part of March, comes the prenuptial molt that brings such marked changes to the male. This molt is extensive, far more so than with most of our birds in the spring, since it includes all of the plumage except flight-feathers and tail-feathers. At the close of the spring molt, about the middle of April as a rule, the male emerges, gorgeous in black breast and yellow trimmings, and with a showy white patch on either wing. The female, with similarly extensive molt, has changed but little in appearance.” He probably intended this as a description of the adult prenuptial molt, but that of the young bird is practically the same. However, the young bird in first nuptial plumage can always be recognized by the faded and worn primaries and tail feathers; otherwise, young and old are essentially alike. Adults have a complete postnuptial molt in August and a partial prenuptial molt, as outlined, in early spring. Mr. Swarth (1926) says: “In winter plumage, old and young, male and female, are all very similar, but there are minor differences by which the old male, at least, may be told from the others. The dark streaks on the sides of the breast are a little more pronounced, the yellow markings a little brighter, and the body color a little clearer gray, as compared with the browner young birds.”

Hybrids, or intergrades, occur occasionally between the different races of auduboni and coronata where their ranges approach or overlap.

Food.—Professor Beal (1907) examined the stomachs of 383 Audubon’s warblers taken in California from July to May, inclusive. The food consisted of 85 percent of animal matter (insects and spiders) and a little more than 15 percent of vegetable matter. The largest item was Hymenoptera, 26 percent, consisting mostly of ants, with some wasps, and a few parasitic species. Diptera accounted for 16 percent, including house flies, crane-flies, and gnats, many of which must have been caught on the wing, as this warbler is a good flycatcher. Bugs, Hemiptera, amounted to nearly 20 percent of the food, including the black olive scale, other scales, plant-lice, stink bugs, leaf-hoppers and tree-hoppers. “Plant lice (Aphididae) were contained in 39 stomachs, and from the number eaten appear to be favorite food. Several stomachs were entirely filled with them, and the stomachs in which they were found contained an average of 71 percent in each.” Caterpillars amounted to nearly 14 percent and beetles more than 6 percent of the food; most of the beetles were injurious species. Other insects and spiders made up about 2 percent.

The vegetable food consisted of fruits, mostly wild and of no value, less than 5 percent, and seeds, over 9 percent, mostly weed seeds and seeds of the poison oak. These warblers have been known to puncture grapes and they probably eat some late fruit, but they do very little damage to cultivated fruits and berries. C. S. Sharp (1903) observed a flock of 200 birds, mostly Audubon’s warblers, greedily eating the raisins in the tray shed of his packing house; they had to be constantly driven away. Mrs. Amelia S. Allen says in her notes that they collect in great flocks in the live oaks to feed on the oak worms in the spring, and that they eat myrica berries in the fall. John G. Tyler (1913) says: “Audubon warblers share with Say Phoebes the habit of catching flies from a window, sometimes becoming so engrossed in this occupation as to cling for several seconds to the screen where a south-facing window offers a bountiful supply of this kind of food.”

Behavior.—Audubon’s warbler is a lively and active bird that seems to be always in a hurry, constantly moving in pursuit of its prey. Mrs. Bailey (1902) writes:

Its flight and all its movements seem to be regulated by gnats, its days one continuous hunt for dinner. When insects are scarce it will fly hesitatingly through the air looking this way and that, its yellow rump spot always in evidence, but when it comes to an invisible gauzy-winged throng it zigzags through, snapping them up as it goes; then, perhaps, closing its wings it tumbles down to a bush, catches itself, and races pellmell after another insect that has caught its eye. In the parks it is especially fond of the palm tops frequented by the golden-crowned sparrows, and dashes around them in its mad helter-skelter fashion. The most straight-laced, conventional thing it ever does is to make flycatcher sallies from a post of observation when it has caught its insect. If it actually sits still a moment with wings hanging at its sides, its head is turning alertly, its bright eyes keen for action, and while you look it dashes away with a nervous quip into midair, in hot pursuit of its prey.

It is not especially timid, being easy to approach when at its nest, and it shows its confidence in human nature by building its nest in trees in parks, over highways, in gardens, and even close to houses. Its behavior in the defense of its young shows a solicitude for their welfare. Jensen (1923) says: “If a nest with young is discovered, both parent birds try every means possible to draw the attention of the intruder away from the nest. Often I have seen them drop with folded wings from the top of a tree and flutter among the leaves as if each had a broken wing.” And Grinnell, Dixon, and Linsdale (1930) write: