300 Birds of Colorado 



c^ Bill wedge-shaped, shorter than the head ; culmen straight. 

 a' Ninth primary longest or equal to the longest. 



Xanthocephalus, p. 304. 



b' Ninth primary shorter than the eighth ; about equal 



to the sixth. Agelaius, p. 306. 



Genus DOLICHONYX. 



Small birds — wing about 4 — with short, conical, finch-like bills ; wing 

 with only the eighth and seventh primaries sinuated on the outer web ; 

 tail with the feathers sharp pointed ; naiddle toe long and claws long 

 and pointed ; plumage of the breeding male chiefly black, of the winter 

 male and female buff, streaked with black. 



This genus contains only the single species here described. 



Bobolink. Dolichonyx oryzivorus. 



A.O.Jj. Checklist no 494 — Colorado Records — Henshaw 75, p. 311 ; 

 Allen & Brewster 83, p. 192 ; Morrison 89, p. 148 ; Cooke 97, pp. 93, 

 163,211; 98, p. 13; Beal 00, pp. 12-22; Henderson 03, p. 107; 

 04, p. 486 ; 09, p. 234 ; Hopkins 06, p. 461 ; Warren 08, p. 22 ; 09, 

 p. 33 ; H. G. Smith 08, p. 186. 



Description. — Male in breeding plumage — General colour above and 

 below black ; nape buff ; scapulars, rump and upper tail-coverts white 

 to grey ; upper-back slightly streaked with buffy ; wings and tail 

 slightly margined with whitish ; feathers of the flanks, thighs and under 

 tail-coverts margined and tipped wath buff ; iris brown, bill black, 

 legs dark brown. Length 6-70 ; wing 4-0 ; tail, 2-75 ; culmen -60 ; 

 tarsus 1-0. 



In summer the nape becomes white or nearly so, and the buffy tips 

 on the flanks and abdomen wear off, leaving those parts plain black. 

 In autvman and winter the male is a rich buff, most of the feathers with 

 black centres ; the crown with a median plain buff and two lateral 

 black stripes, the wings and tail chiefly dusky, the sides of the breast, 

 flanks and under tail-coverts marked with black streaks, and the bill 

 pale brown. 



The female resembles the winter male, but is a good deal smaller 

 (wing 2-5, tail 2-5) and less richly coloured ; in summer it is a good 

 deal paler than in early spring, and has the black streaks more plainly 

 defined. The yoimg bird resembles the female, but the buff is a richer 

 shade and there is a faint row of black spots across the chest. 



The change of plumage in the male is acquired by a double moult, 

 one in the early fall before the southward migration, the other in early 

 spring before coming north, while the change from the early spring to 

 the summer plumage is brought about by abrasion of the buffy tips 

 to the feathers. 



