BLACK-FRONTED WARBLER. 65 



the winter in southern Oregon. The winter range extends over most 

 of Mexico to Guatemala; the species is most abundant in western 

 Mexico and the higher districts of the eastern and southern parts. 



Spring rnigration. — As would be expected from the winter range 

 of the Audubon warbler, the dates of spring arrival are very different 

 in the eastern and western portions of its habitat, respectively. In 

 southern Arizona and southern New Mexico the first birds arrive in 

 March, advance to northern Colorado by the third week in April, and 

 reach the Black Hills in the first week of Ma}^ Passing northwest- 

 ward, the average dates of arrival are April 29 at Great Falls, Mont. ; 

 April 23 at Columbia Falls, Mont. ; and March 20 in southern British 

 Columbia. On the plains of eastern Colorado and western Kansas, 

 where the species is known only as a migrant, the dates are all late — 

 from April 29 to May 27. 



Fall migration. — In August the mountain breeding birds begin to 

 descend to lower altitudes, and during September reappear on the 

 plains. The earliest migrants move south of the breeding range in 

 the last week of September and enter Mexico soon after the 1st of 

 October. The northern part of the range in Montana is deserted 

 about the 10th of October. 



656a. Dendroica auduboni nigrifrons Brewster. Black-fronted Warbler. 



Breeds in the mountains of northwestern Mexico and north to the 

 mountains of southern Arizona. The winter range has not yet been 

 determined, but the parties of the Biological Survey have taken the 

 bird in fall migration at 6,000 feet in Durango. The arrival of the 

 first migrant was noted May 9, 1902, in the Huachuca Mountains, 

 Arizona, and an exceptionally early migrant was seen April 5, 1903. 



657. Dendroica maculosa (Gmel. ) . Magnolia Warbler. 



Breeding range. — One of the best examples of a species limited dur- 

 ing the breeding season to the Canadian zone is the magnolia warbler. 

 Its breeding range is from the higher parts of Massachusetts, northern 

 New York, northern Michigan, northern Minnesota, and southern 

 Assiniboia (Wood Mountain) to Newfoundland, northern Quebec, 

 Hudson Bay, Lesser Slave Lake, Fort Simpson, and the Nahanni 

 Mountains. It is rare or casual in British Columbia. It breeds not 

 uncommonl}^ near the summits of the Allegheny Mountains of eastern 

 Pennsylvania, in a region that in the higher portions probably furnishes 

 Canadian conditions. The same is probably true of its southernmost 

 breeding home in western Maryland where it nests on the highest 

 mountains. 



Winter range. — The winter distribution of the magnolia warbler is 

 about as extensive as the breeding area, but while in the summer the 

 species is a bird of the Canadian life zone, in winter it is an inhabitant 

 6152— No. 18—04 5 



