iBLAOK-THBOATED GRAY WARBLEB. 87 



665. Dendroica nigrescens (Towns.). Black-throated Gray Warbler. 



The black-throated gray warbler is another of the warblers of the 

 western United States. Its breeding range extends from southern 

 California and southern Arizona north to Briti^sh Columbia and east to 

 central Colorado, and rises to an altitude of 9,500 feet. The species 

 migrates in winter to Mexico and ranges from Oaxaca and Vera Cruz 

 to as far north as Durango, where it was noted by the parties of the 

 Biological Survey. 



Spring migration.— The. black-throated gray warbler enters southern 

 California in the first week in April and reaches southern British 

 Columbia by the third week in the month. The earliest dates in south- 

 ern Arizona and southern New Mexico are included between March 

 31 and April 9, while the species reaches early in May the northern 

 portion of its range in Colorado. 



Fall migration.— Tae last fall migrants of the species do not leave 

 central California until the first week in October, and do not desert 

 the State until after the middle of the month. 



666. Dendroica chrysoparia Scl. & Salv. Golden-cheeked Warbler. 



This rare species breeds in Texas and retires in winter to Mexico 

 and Guatemala. The winter range is not well known. The known 

 breeding range is a restricted area in south-central Texas north to about 

 latitude 31°. Its arrival near San Antonio, Tex. , was noted March 13, 

 1895, March 10, 1896, March 9, 1897, March 13, 1898, and March 14, 

 1900— average, March 12. 



667. Dendroica virens (Gmel.). Black-throated Green Warbler. 



Breeding range. — The black- throated green warbler is one of the 

 most abundant of its family. It breeds commonly from southern New 

 England north to the Gulf of St. Lawrence and Newfoundland and 

 in the mountains of Pennsylvania, the Catskills, northern and western 

 New York, Michigan, northern Illinois, Wisconsin, Minnesota, northern 

 Alberta (Edmonton), and southwestern Athabasca (Peace River Land- 

 ing). It breeds less commonly southward in the higher Alleghenies to 

 South Carolina. It was taken several times near the outlet of Athabasca 

 Lake by one of the parties of the Biological Survey. The range as 

 described shows that the black-throated green warbler belongs to the 

 Canadian zone and the northern part of the Alleghenian. 



Migration range. — Western Assiniboia, western Minnesota, eastern 

 Nebraska, and eastern Kansas mark the western limit of the species in 

 migration. West of the heavy forest area of the Mississippi it is rare. 

 Through eastern Texas it is more common, as this is one of its regular 

 migration routes to southern Texas and eastern Mexico. 



Winter range.— The winter home of the species is in heavy, low- 

 lying forests, much lower than would be expected from its summer 



