As soon as the young hatch the female begins feeding them. I have seen no evidence of regurgitation. She thoroughly crushes caterpillars, etc., between her mandibles before giving them to the young. Their food for the first day consists of small insects, soft white grubs and a large number of half inch, smooth, green caterpillars, which are found on hemlock trees. From the second to the eighth day their diet consists chiefly of small green caterpillars, insects, white grubs and an occasional may-fly or gray and cream colored caterpillar without spines. On the ninth and tenth day their diet still includes white grubsand green caterpillars, but dragon flies and may-flies are the chief staples. Slugs, winged ants, white cabbage butterflies and moths are also on the menu.From the time the young hatch until they are five days old the parents swallow the faecal sacs. After that they carry them away from the nest and place them on the branches of neighboring trees—frequently using dead branches.
As soon as the young hatch the female begins feeding them. I have seen no evidence of regurgitation. She thoroughly crushes caterpillars, etc., between her mandibles before giving them to the young. Their food for the first day consists of small insects, soft white grubs and a large number of half inch, smooth, green caterpillars, which are found on hemlock trees. From the second to the eighth day their diet consists chiefly of small green caterpillars, insects, white grubs and an occasional may-fly or gray and cream colored caterpillar without spines. On the ninth and tenth day their diet still includes white grubsand green caterpillars, but dragon flies and may-flies are the chief staples. Slugs, winged ants, white cabbage butterflies and moths are also on the menu.
From the time the young hatch until they are five days old the parents swallow the faecal sacs. After that they carry them away from the nest and place them on the branches of neighboring trees—frequently using dead branches.
She gives a detailed account of the development of the young and their manner of leaving the nest naturally on the tenth day. During the 6 days when she thought it safe to handle them without driving them out of the nest too soon, one increased in weight from 22 grains to 141, and another from 24 to 147 grains.
Plumages.—The sexes differ slightly in the juvenal plumage. The young male is olive-brown above; the wings are blackish, the primaries edged with bluish-leaden-gray; the wing coverts, secondaries, and tertials are margined with olive-green, and there is a white patch near the base of the primaries, as in the adult; the tail is much like that of the adult; the under parts are brownish, tinged with yellowish on the throat and abdomen; the lores and two submalar streaks are dusky, and the superciliary stripe is yellowish white. The young female is similar, but has dull brown wings and tail with greenish instead of bluish edgings, and the white area in the primaries is smaller, more dingy and sometimes obscure.
A partial postjuvenal molt occurs in late July and August involving the contour plumage and the wing coverts but not the rest of the wings or the tail, producing a first winter plumage in which the sexes become decidedly differentiated and not very different from the adults at that season. This is one of the few wood warblers in which the fall plumage is very much like the spring dress. In the young male the blue of the upper parts is not as clearly blue as in the adult; the feathers of the back are faintly edged with olive-green, those of the black throat veiled with dull whitish, and the abdomen is tinged with yellowish. The young female differs from the fall adult in being greener above, without bluish tinge, and more buffy or yellowish below.
There is a limited prenuptial molt about the head, and wear has removed most of the edgings and fading has made the under parts clearer. At this age, young birds can be distinguished from adults by the worn and dull brown wings and tail. Subsequent molts and plumages, in which young and old are alike, consist of a complete postnuptial molt in July and August and a limited prenuptial molt about the head. The adult male in the fall is only slightly tipped with greenish above and with whitish on the black throat, which may be somewhat less in extent.
Food.—No thorough study of the food of the black-throated blue warbler seems to have been made, but probably all of the items mentionedas food for the young are also eaten by the adults. Forbush (1929) adds the hairy tent caterpillar, flies, beetles, and plant lice. Aughey (1878) found 23 locusts and 15 other insects in one stomach collected in Nebraska. Dr. Wetmore (1916) reports on the contents of eight stomachs collected in Puerto Rico, in which animal matter formed 75.5 percent and vegetable matter 24.5 percent of the food. “The vegetable food was found in the three stomachs taken in December and January and consisted of seeds of the camacey (Miconia prasina).” The principal items in the animal food were lantern flies (Fulgoridae), 19.46 percent, various weevils, 14.25 percent, flies, 10.09 percent, and spiders, 12.62 percent. A few beetles and one ant were eaten. Most of the food consisted of harmful insects.
Behavior.—The black-throated blue warbler is one of the tamest and most confiding of all our wood warblers. I was able to photograph (pl. 30) the female incubating and both sexes feeding the young at very short range without any special concealment; they are very devoted parents and show great concern when the safety of their young is threatened, trailing along the ground with the broken-wing act in great distress.
Gerald Thayer wrote to Dr. Chapman (1907): “In its movements the Black-throated Blue is more deliberate than many of its relatives, but it has at the same time a somewhat Redstart-like way of ‘spiriting’ itself from one perch to another, and, while perched, of partly opening its white-mooned wings;—a habit and a marking shared by the boldly blue-and-black-and-white males and the dimly green and yellowish females and young.”
Henry D. Minot (1877) writes:
They are very dexterous in obtaining their insect prey; sometimes seizing it in the air, with the skill of a true Flycatcher, and at other times finding it among the branches of the various trees which they frequent. Now they twist their heads into seemingly painful postures, the better to search the crannies in the bark or blossoms, now spring from a twig to snap up an insect in the foliage above their heads, instantly returning, and now flutter before a cluster of opening leaves, with the grace of a Hummingbird. Occasionally they descend to the ground, and are so very tame that once, when I was standing motionless, observing some Warblers near me, one hopped between my feet to pick up a morsel of food.
Voice.—Aretas A. Saunders has sent me the following study of the song: “The song of the black-throated blue warbler, in its more typical forms, is one of only three or four slowly drawled notes in a peculiarly husky voice, the last note commonly slurred upward. While the number of notes in the songs varies in my 41 records from two to seven, more than half of them are of only three notes, and most of the others are of four or five. In all, 22 songs end with the upward slur of the last note, 14 in an unslurred note and 5 in a downward slur.The general trend of the pitch is upward in 29 records, downward in 10, and ending in the same pitch as the first note in 2.
“The pitch of songs varies from G‴ to E‴´, a range of four and a half tones. Single songs range from half a tone to three tones, the majority covering one and a half or two tones. The length of the songs is from 11⁄5to 2 seconds. This indicates the slowness of the three or four notes, for other warbler songs with twice as many notes are about the same length. In the few songs of this bird that have more notes the notes are shorter and faster, so that the songs are not longer.
“This species shows a greater tendency to sing unusual songs than most warblers. On three occasions I have heard a warbler song that I could not recognize, and when I located the bird, found it to be a black-throated blue.
“Two of these songs were of rapid notes, in a clear, ringing quality, not at all like the ordinary song of this bird. The third was two rather long notes in a clear, sweet whistle, the second higher in pitch than the first, so that it resembled thephoebewhistle of the chickadee reversed.
“The average date of the last song in 14 summers in Allegany State Park is July 21. The earliest is July 14, 1927 and 1940, and the latest July 29, 1931. The song is rarely revived in August, after the molt.”
Francis H. Allen (MS.) writes the two common songs as “quee quee quee-e-e´” and “que-que-que-que quee-ee´,” and says further, “in June 1907, I heard a bird in Shelburne, Vt., that sang persistently a short song likekū quee-e-e´besides singing occasionally one of the ordinary songs. In May, 1910, at Jaffrey, N. H., I heard a bird sing over and overqui-qui-qui-qui-qui-qui-qui-qui-quee´, but most of the birds of the region seemed to singzee zee zee-ee, with a falling inflection, while some sang the ordinaryquee quee quee-e-e´, with rising inflection. Thequeesongs have a nasal tone. The call note is a drychutorchet, resembling thechipof the black-throated green but not so thick.”
Mrs. Nice (1930b) describes four different songs; and Gerald Thayer, in Chapman (1907), gives four main songs, with variations, but the versatility of this singer seems to be well enough shown in the previous descriptions.
Field marks.—The male black-throated blue warbler could hardly be mistaken for anything else; there is no other American warbler that is at all like it. The blue back, the extensive black throat, the white patch near the bases of the primaries, the white under parts, and the white spots on the inner webs of the three outer tail feathers are all diagnostic. Fortunately, the fall plumage is essentially the same. But the female is one of the most difficult of the warblers torecognize, olive-green above and buffy below; the only distinctive marks are the white patches in the wings and tail, similar to those of the male, but smaller, duller, and sometimes obscure.
Fall.—As soon as the molting season is over, late in August, old and young birds begin to drift away from their summer haunts; most of them depart from New England during September or even late August. Birds from New England and farther north pass through the Atlantic Coast States to Florida and the West Indies, while those from the interior migrate slightly southeastward and across the lower Alleghenies to join them. Professor Cooke (1904) writes:
Black-throated blue warblers strike the lighthouse at Sombrero Key in greater numbers than any other kind of bird, particularly during the fall migration.* * *In five years’ time they struck the light on seventy-seven nights, and as a result 450 dead birds were picked up on the platform under the lantern. Probably a still larger number fell into the sea. Adding to these those that were merely stunned and that remained on the balcony under the light until able to resume their journey, the keeper counted 2,000 birds that struck. There were two nights, however, when the numbers of this species were so great that no attempt was made to count them. The Fowey Rocks lighthouse was struck on thirty different nights. It is certain, therefore, that the black-throated blue warbler passes in enormous numbers along both coasts of southern Florida.
Winter.—Professor Cooke (1904) observes that “the winter home of the black-throated blue warbler is better defined than that of any other common warbler, and allows a very exact determination of the square miles of territory occupied by it at this season. Cuba, Haiti, and Jamaica, with a combined area of 74,000 square miles, are doubtless occupied during the winter by the great majority of the individuals of the species. The remaining birds do not probably cover enough territory to bring the total to 80,000 square miles. This is a small area compared with that occupied during the breeding season.” In his Birds of Cuba, Dr. Thomas Barbour (1923) writes:
The Black-throated Blue Warbler is excessively common, early to arrive and late to leave. It is one of the tamest and most confiding species, and one to be found in all sorts of situations. Early pleasant days in Cuba spent at Edwin Atkins’ plantation, Soledad, near Cienfuegos, brought a great surprise, for I found it not uncommon to have these little Warblers enter my room through the great ever open windows and flit from couch to chair. This happened often, notably at Guabairo, not far from Soledad. So inquisitive and confiding are they, that one can hardly recognize the rather retiring dweller in woodland solitude which we know in the North.
DISTRIBUTION
Range.—Eastern North America, from southern Canada to northern South America.
Breeding range.—The black-throated blue warbler breedsnorthto southwestern and central Ontario (Lac Seul, Kapuskasing, and LakeTimiskaming); and southern Quebec (Blue Sea Lake, Quebec, Godbout, and Mingan).Eastto 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).Southto 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).Westto 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 foundnorthto the Bahamas (Andros, Nassau, and Watling Islands).Eastto Puerto Rico (Río Piedras) and the Virgin Islands (St. Croix).Southto Puerto Rico (Maricas); Hispaniola (Paraíso, Dominican Republic; and Jérémie, Haiti); Jamaica (Spanishtown); and the Swan Islands.Westto 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 31⁄2hours. On afew 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 toD. 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. cairnsiaveraging slightly larger, in fact, thanD. c. caerulescens), and the other only partially so, since many specimens ofD. c. cairnsihave little if any black on the back, while many ofD. c. caerulescenshave quite as much as the average amount shown inD. c. cairnsi.”
The 1931 A. O. U. Check-List gives the breeding range ofcairnsias 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.
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.
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 chestnuttrees, 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 21⁄2feet 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 measure19.0by 13.0, 17.9 by13.4, and16.0by12.0millimeters (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 namecoronataand 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 moreextensive. 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 feathersof 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 13⁄4inches 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 21⁄4inches in height and 3 by 31⁄2inches in diameter; the cup is 2 inches in diameter and about 11⁄2inches 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 aboutsome 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 morecommonly 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 measure20.3by 13.2, 17.9 by14.8,14.8by 12.9, and 16.0 by12.4millimeters (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.
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 foundthe 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 andtails, 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 ofRhus, 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: