EASTERN VESPER SPARROW 869 



song of the morning at 4:05 a.m. (e.s.t.). Thereafter singing was 

 ahnost continuous until about 11:00 o'clock, at which time it subsided 

 for about two hours. Singing after sunset, even in the gathering dusk, 

 is a common midsummer phenomenon." The vesper sparrow is, 

 however, better known to many for its white outer tail feathers, which 

 provide an excellent field mark when the bird flies away from the 

 observer, rather than for its song (which some confuse with that of 

 the song sparrow). 



Spring. — The first vesper sparrows usually arrive in the northern 

 states (Massachusetts, New York, Michigan, Minnesota) during the 

 last week or 10 days of March, and the spring migration is well under 

 way by the first week of April. In Ohio, M. B. Trautman (1940) 

 reports that "throughout spring the species principally inhabited the 

 better-drained and more upland fields and pastiu-es. It was found in 

 greatest numbers in sparsely vegetated fields, and in close-cropped 

 pastures and meadows. It never flocked in large numbers in spring, 

 and seldom more than 15 birds were seen in a well-organized flock, and 

 then only early in the season. During the last haK of the migration it 

 was always well scattered over fields and pastures. When several 

 birds were flushed they did not group together, but flew a short 

 distance by themselves and dropped independently to earth." In his 

 report on the birds of Lucas County, Ohio, L. W. Campbell (1940) 

 states that spring flocks of 25 or 30 birds were sometimes seen and 

 that the greatest number seen in one day was 100 (on Mar. 31, 1932). 

 Cordeha J. Stanwood (MS.) writes that at Ellsworth, Maine, the 

 first vesper sparrows were seen "in mid-April, or a few days earher." 

 Her earhest record was Apr. 6, 1909; on Apr. 13, 1916, she saw about 

 30 birds, the first seen that year. 



Territory. — Although much remains to be learned about the 

 territorial behavior of the vesper sparrow, we know that this species 

 uses a much larger home range than do certain other sparrows. On 

 a 10-acre field near Ypsilanti, Mich., cultivated in part the previous 

 year and surrounded by woods on three sides, I found 15 pairs of 

 song sparrows, 8 pairs of field sparrows, and only 3 pairs of vesper 

 sparrows, all of which had estabhshed nesting territories. At the 

 Edwin S. George Reserve, also in southern Michigan, Francis C. 

 Evans (MS.) studied a 14-acre uncultivated field for 8 yeai-s (1949-56). 

 He found that the number of breeding territories vesper sparrows 

 established during this period "has ranged from a minimum of 8 to 

 a maximum of 12. The entire field seems to be utilized by the birds, 

 and this would give an average territory size ranging from 1.2 acres 

 at the highest population density to 1.8 acres at the lowest density. 

 However, the birds have frequent recourse to the adjacent woods, 

 penetrating at least 50 or 60 yards, and if territory boundaries are 



