18 NORTH AMERICAN WARBLERS. 



light or resting bewildered on the balcon}^ after striking. Eight hun- 

 dred and sixteen records were received in five years from this one 

 lighthouse. They comprise a total of 2,011 dead birds and 10,086 

 birds which struck the light with so little force that on the return of 

 clear skies or dajdight they were able to resume their flight. Warblers 

 migrate chiefly by night and are so susceptible to the influence of a 

 bright light that they constitute at least 80 percent of these thousands. 

 The most valuable part of the present report is based on the migra- 

 tion schedules contributed to the Biological Survey during the past 

 twenty years by voluntary observers throughout the Union. To each 

 and all of these sincere thanks are hereby tendered. 



636. Mniotilta varia (Linn.)- Black and White Warbler. 



Breeding range. — The southern limit of the principal breeding range 

 of the black and white warbler is the southern boundary of the Caro- 

 linian life zone from North Carolina to Kansas. Records of the sup- 

 posed breeding of the species in the Austroriparian zone in Texas, 

 Louisiana, and northern Florida are quite numerous. Most of them, 

 however, are based on records of young birds appearing so early in 

 the summer that the}^ were believed to have been reared in the imme- 

 diate vicinity. The black and white warbler is, however, one of the 

 very earliest of migrants. At the southern limit of its range it nests 

 in April, giving the young abundant time to be strong- winged by early 

 in July. It certainly does not breed in southern Florida, yet both 

 adults and young of the year have been noted at Key West, Fla., by 

 the middle of Jul}^, so that July dates in the Gulf States are not evi- 

 dence of breeding. The breeding range extends north to New Bruns- 

 wick, Nova Scotia, Newfoundland, Hudson Bay, and Fort Norman, 

 Mackenzie; west regularly to central South Dakota, central Kansas, 

 and central Texas, and casually to Lesser Slave Lake and Peace River 

 Landing, Athabasca, Colorado (two breeding records), and California 

 (three breeding records). 



Winter range. — The black and white warbler has a limited range in 

 South America, but is common in the Santa Marta region of north- 

 eastern Colombia — on the coast at Bonda,^' and Santa Marta,^ and in 

 the mountains at Minca (2,000 feet),^ Onaca (2,500 feet)," and Las Nubes 

 (5,000 feet).^^ On the coast it is noted in the fall; in the mountains it 

 occurs from December to March. Farther south it is recorded from 

 Bucaramanga (3,000 feet),^^ from near there at Herradura (4,000 feet),^ 

 and from Bogota.-^ In the State of Antioquia it was taken at Concordia 



"Allen, Bull. Am. Mus. Nat. Hist., XIII, p. 178, 1900; Auk, XVII, 367, 1900. 

 & Bangs, Proc. Biol. Soc.Wash., XII, 143, 1898. 

 ^^Salvin and Godman, Ibis, p. 117, 1880. 

 ^Berlepsch, J. f. Orn., p. 282, 1884. 

 ^Wyatt, Ibis, p. 322, 1871. 



/Sclater, Cat. Am. Birds, p. 26, 1862; P. Z. S., p. 143, 1855; Sharpe, Cat, Birds 

 Brit. Mus., X, p. 253, 1885. 



