Part 77

Enemies.--Dr. Friedmann (1929) calls the Blackburnian warbler "a very uncommon victim of the Cowbird." Dr. Merriam (1885) records a nest of this warbler that was 84 feet from the ground, containing four warbler's eggs and one of the cowbird, of which Friedmann remarks: "This is probably the altitude record for a Cowbird's egg, bettering by some twenty feet my highest record at Ithaca, a Cowbird's egg in a nest of a Pine Warbler about sixty feet up."

Harold S. Peters (1936) records two species of lice, Menacanthus chrysophaeum (Kellogg) and Ricinus pallens (Kellogg), and one mite, Proctophyllodes sp., as external parasites of this warbler.

Field marks.--The adult male Blackburnian warbler in spring plumage is unmistakable, with its black upper parts, large white patch in the wings, orange stripe in center of the crown and another over the eye, and, especially, the flaming orange throat and breast. The female in the spring and the male in the fall are similarly marked, but the colors are much duller. The colors of young birds in the fall are even duller, and the back is brownish, but the white outer web of the basal half of the outer tail feather should indicate the species.

Fall.--Early in August, young and old birds begin to gather into flocks preparing to migrate, and before the end of that month most of them have left their breeding grounds. All through August and most of September, we may see them drifting through our deciduous woods in mixed flocks with other species of warblers. These migrating flocks are generally so high up in the tree tops and are so active in their movements that it is not easy to identify them in their dull winter plumages.

By early October, most of the Blackburnian warblers have passed beyond the United States, en route to their winter home in South America. Professor Cooke (1904) says: "By the middle of October the earliest migrants have reached Venezuela and Ecuador. The main army of the Blackburnians pass the south end of the Alleghenies between September 25 and October 5, and during the first two weeks of October are moving through San José, Costa Rica, and by early in November are settled for the winter in Perú."

Dickey and van Rossem (1838) refer to it as a "fairly common fall migrant and very rare winter visitant in the Arid Lower Tropical Zone" in El Salvador, but "not seen in spring."

Winter.--Dr. Alexander F. Skutch contributes the following notes: "Rarely recorded, and apparently only as a bird of passage, in Guatemala, the Blackburnian warbler is a moderately abundant winter resident in Costa Rica. Here it passes the winter months on both slopes of the Cordillera, from about 1,500 to 6,000 feet above sea-level, but is far more abundant above than below 3,000 feet. It is found in midwinter both in heavy forest and among scattered tall trees. Although the birds appear to arrive in flocks in late August or September, they soon disperse through the woodland and show slight sociability. Yet one or two may at times join a mixed flock of Tennessee warblers and other small birds. Restlessly active, the Blackburnian warbler forages well above the ground, where it is difficult to see. I have never heard its song in Central America.

"Early dates of fall arrival are: Guatemala--Chimoxan (Griscom), October 1; Panajachel (Griscom), October 4. Costa Rica--San José (Cherrie), September 8; San José (Underwood), Septem 10; La Hondura (Carriker), September 19; San Isidro de Coronado, September 8, 1935; Vara Blanca, August 19, 1937; Cartago, September 13, 1938; Murcia, September 14, 1941; Basin of El General, September 16, 1936; Ujarrás (Carriker), September 12. Ecuador--Volcán Tungurahua, 7,400 feet, October 12, 1939.

"Late dates of spring departure from Central America are: Costa Rica--Basin of El General, March 25, 1936, March 13, 1937 and April 18, 1943; Vara Blanca, May 7, 1938; Pejivalle, April 23, 1941; Bonilla (Basulto), April 10. Guatemala--Finca Sepacuite (Griscom), May 10."

DISTRIBUTION

Range.--Southern Canada east of the Great Plains to Central Perú.

Breeding range.--The Blackburnian warbler breeds =north= to southern Manitoba (Lake St. Martin and Berens Island, Lake Winnipeg); central Ontario (Lac Seul, Lake Abitibi, and North Bay; has occurred at Trout Lake); and central Quebec (Blue Sea Lake, Lake Albanel, rarely; Lake St. John and Gaspé; possibly Pointe de Monts and Natashquan). =East= to eastern Quebec (Gaspé); eastern New Brunswick (Bathurst and Tabusintac); and eastern Nova Scotia (Antigonish and Halifax). =South= to Nova Scotia (Halifax); southern Maine (Calais, Lewiston, and Portland); Massachusetts (Cambridge, Springfield, and Sheffield); northern New Jersey (Kittatinny Mountains); central Pennsylvania (Mauch Chunk and Carlisle); and south through the mountains of Maryland, Virginia, West Virginia, North and South Carolina and Tennessee to northern Georgia (Brasstown Bald and Burnt Mountain); western Pennsylvania (Leasureville and Meadville); northeastern Ohio (Pymatuning Swamp and possibly Geneva); northern Michigan (Bay City and Wequetonsing); northern Wisconsin (New London, Unity and Ladysmith); and northern Minnesota (Elk River, Onamia, and Itasca Park). =West= to northwestern Minnesota (Itasca Park) and southeastern Manitoba (Winnipeg and Lake St. Martin).

A possible future extension of range westward is seen in records from Saskatchewan: it was recorded four times near Indian Head 1888-1901; one at Last Mountain Lake in 1920, at Lake Johnston in 1922; and at Emma Lake in the summer of 1939, possibly breeding.

Winter range.--The Blackburnian warbler is reported to winter commonly in Costa Rica, but as yet has been found in Panamá only as a migrant. In South America it is found =north= to northern Colombia (Santa Marta region); and central northern Venezuela (Rancho Grande). =East= to northwestern Venezuela (Rancho Grande, Mérida, and Páramo de Tamá); the eastern slope of the Andes in Colombia (Pamplona, Bogotá, and San Antonio); Ecuador (Mount Sumaca, Machay, and Zamora); and Perú (Chinchao and Huambo). =South= to central Perú (Huambo and Anquimarca). =West= to western Perú (Anquimarca and Tambillo); Ecuador (Ambato, Quito, and Parambo); and Colombia (Concordia, Medellín, and the Santa Marta region). It is casual in migration in the Bahamas and Cuba.

Migration.--Late dates of spring departure from the winter home are: Perú--Chelpes, April 22. Ecuador--Quito, May 10. Venezuela--Rancho Grande, April 22. Colombia--La Porquera, April 24. Costa Rica--Vera Blanca, May 7.

Early dates of spring arrival are: Panamá--Garachiné, March 5. Florida--Pensacola, April 5. Alabama--Hollins, April 4. Georgia--Athens, March 29. South Carolina--Aiken, April 17. North Carolina--Weaverville, April 16. Virginia--Lynchburg, April 25. West Virginia--White Sulphur Springs, April 17. District of Columbia--Washington, April 23. Pennsylvania--Renovo, April 27. New York--Rochester, April 26. Massachusetts--Melrose, April 29. Vermont--Wells River, April 30. Maine--Portland, May 4. New Brunswick--Scotch Lake, May 5. Quebec--Montreal, May 10. Louisiana--Lake Borgne, March 27. Mississippi--Gulfport, March 27. Tennessee--Chattanooga, March 31. Kentucky--Lexington, April 12. Indiana--Brookville, April 15. Ohio--Oberlin, April 19. Michigan--Hillsdale, April 22. Ontario--London, April 27. Arkansas--Huttig, April 15. Missouri--Bolivar, April 20. Iowa--Davenport, April 28. Wisconsin--Unity, April 27. Minnesota--Waseca, April 30. Texas--Boerne, March 31. Nebraska--Stapleton, May 1. South Dakota--Vermilion, May 3. Manitoba--Aweme, May 14.

Late dates of spring departure of transients are: Florida--Pensacola, May 9. Alabama--Autaugaville, May 12. Georgia--Athens, May 7. South Carolina--Spartanburg, May 12. North Carolina--Greensboro, May 17. Virginia--Charlottesville, May 28. District of Columbia--Washington, June 3. Pennsylvania--Norristown, May 30. New York--New York, June 7. Louisiana--New Orleans, April 23. Mississippi--Corinth, May 12. Kentucky--Lexington, May 16. Illinois--Lake Forest, June 9. Ohio--Toledo, June 12. Arkansas--Rogers, May 12. Missouri--Kansas City, May 30. Iowa--Sigourney, June 1. Texas--Commerce, May 18. Nebraska--Fairbury, May 26. South Dakota--Yankton, June 2.

Late dates of fall departure are: Saskatchewan--Last Mountain Lake, September 1. Nebraska--Fairbury, October 14. Texas--Brownsville, October 2. Minnesota--Saint Paul, September 25. Wisconsin--Madison, September 27. Ontario--Hamilton, October 3. Michigan--Ann Arbor, October 8. Indiana--Waterloo, October 17. Kentucky--Danville, October 16. Missouri--St. Louis, October 6. Tennessee--Memphis, October 28. Arkansas--Chicat, October 4. Mississippi--Eudora, October 24. Louisiana--New Orleans, October 9. Quebec--Hatley, September 30. New Brunswick--Scotch Lake, September 28. Maine--Phillips, September 17. New Hampshire--Hanover, September 24. Massachusetts--Wellesley, October 23. New York--Canandaigua, October 12. Pennsylvania--Berwyn, October 19. District of Columbia--Washington, October 10. West Virginia--Bluefield, October 8. Virginia--Sweet Briar, November 1. Georgia--Tifton, November 2. Alabama--Birmingham, October 25. Florida--Arcadia, October 30. Cuba--Bosque de la Habana, October 30.

Early dates of fall arrival are: North Dakota--Argusville, August 23. Texas--Commerce, August 28. Illinois--Glen Ellyn, August 19. Ohio--Little Cedar Point, July 31. Kentucky--Versailles, August 31. Tennessee--Nashville, August 29. Mississippi--Bay St. Louis, August 11. New York--New York, August 11. Pennsylvania--Berwyn, August 19. District of Columbia--Washington, August 2. Virginia--Charlottesville, August 10. North Carolina--Mount Mitchell, July 30. Georgia--Savannah, August 10. Florida--Key West, July 29. Cuba--Santiago de las Vegas, September 20. Costa Rica--San José, August 17. Colombia--Santa Isabel, September 22. Venezuela--Escorial, October 14. Ecuador--Tumbaco, October 12. Perú--Tambillo, November 19.

Casual records.--A specimen of Blackburnian warbler was collected at Frederickshaab, Greenland, on October 16, 1845. One was taken at Ogden, Utah, in September 1871, and another near Fort Bayard, N.M., in May 1876. On August 21, 1924, a male was watched closely for sometime near Libby, Mont.

Egg dates.--Maine: 5 records, June 2 to 17.

New York: 23 records, May 29 to July 6; 16 records, June 7 to 17, indicating the height of the season.

New Hampshire: 6 records, May 23 to June 18.

Pennsylvania: 5 records, May 28 to June 9.

Quebec: 2 records, June 15 and 20.

DENDROICA DOMINICA DOMINICA (Linnaeus)

EASTERN YELLOW-THROATED WARBLER

CONTRIBUTED BY ALEXANDER SPRUNT, JR.