The Migration of North American Sparrows 



THIRTY-FIRST PAPER 



Compiled by Prof. W. W. Cooke, Chiefly from Data in the Biological Survey 



With Drawings by Louis Agassiz Fuertes 



(See Frontispiece) 



WHITE-WINGED JUNCO 



The migrations of the White-winged Junco are quite restricted, since the 

 larger part of the birds breed in the Black Hills of South Dakota and the 

 neighboring parts of Wyoming and Nebraska, and winter in the southern half 

 of eastern Colorado. Thus the average distance traveled in migration is rather 

 less than 500 miles. The first arrive in fall migration at Boulder, Colo., on the 

 average, October 20, earliest October 17, 1909; Colorado Springs, Colo., 

 average October 23, earliest October 19, 1892. They remain common all 

 winter, and the larger part leave for their summer home in March. The last was 

 seen in Mesa County, Colo., April 2, 1902, and the last at Colorado Springs, 

 Colo., April II, 1874. 



SLATE-COLORED JUNCO 



The Slate-colored Junco is one of the most abundant and well-known 

 birds of the United States, east of the Rocky Mountains. From the eastern 

 foothills of these mountains to the Pacific this species is broken up into several 

 subspecies, but, very strangely, these forms extend north only to southern or 

 central Alaska, and the Juncos of northern and northwestern Alaska are birds 

 that winter in the eastern United States, and in spring migration pass up the 

 Mississippi Valley, cross the Saskatchewan to the Mackenzie Valley, and thence 

 turn almost due west and cross the Rocky Mountains to northern Alaska. A 

 subspecies, the Carolina Junco, breeds in the higher parts of the southern 

 Alleghanies from Georgia to Maryland; and it may be that some of the records 

 from the southeastern United States given beyond for the Slate-colored Junco 

 belong to the Carolina Junco. It is interesting to note how long the Junco 

 remains close to the breeding-grounds before beginning the fall migration. No 

 Juncos were seen at Weaverville, N. C, before October 18, though they nested 

 upon the neighboring mountains, within five minutes' flight. In the spring, 

 the last one left for the mountains April 19, though the nest-building coidd 

 not occur until several weeks later. 



SPRING MIGRATION 



PLACE 



Alfred, N. Y 



Boonville, N. Y... . 

 Ballston Spa, N. Y, 



Number 

 of years' 

 record 



15 



7 

 7 



Average date of 

 spring arrival 



March 19 

 March 24 

 April I 



Earliest date of 

 spring arrival 



March 5, 1910 

 March 14, 1903 

 March 22, 1910 



(438) 



