70 U.S. NATIONAL MUSEUM BULLETIN 237 part i 



wing bands and narrow tipping of the tail buff. Below rich clay- 

 color, pale buff on the chin, abdomen and crissum. * * *" 



The first winter plumage of the male is acquired by a partial post- 

 juvenal molt in August, involving the contour plumage and the wing 

 coverts, but not the rest of the wings nor the tail. Dr. Dwight says 

 that it is similar to the juvenal plumage, but "the browns everywhere 

 darker and richer especially noticeable on the median wing coverts 

 which become deep hazel, the crissum which becomes cinnamon or 

 dusky-streaked and the lores which are dull sepia-brown." 



He says that the first nuptial plumage is acquired by a partial pre- 

 nuptial molt, "which involves a variable amount of the brown body 

 plumage and wing coverts, the tail wholly or in part and apparently 

 the outer primaries in some cases. A mixture of brown and blue 

 results, the key to the age of a specimen being the retained brown 

 primary coverts. The moult must occur in mid-winter judging by the 

 worn condition of spring specimens." 



The adult winter plumage is acquired by a complete postnuptial 

 molt. "The full blue plumage is assumed, veiled with cinnamon 

 feather tips on the head and back, a deeper band across the throat, 

 these edgings very pale elsewhere below. The wings are black with 

 blue edgings, those of the lesser and median coverts rich chestnut, of 

 the greater coverts paler, of the tertials still paler; the tail darker 

 than the wings and with deeper blue edgings, the outer pair of rec- 

 trices narrowly tipped with white. The lores are black." 



The adult nuptial plumage is acquired by wear, without molt. 



Of the plumages of the female, he writes: 



The plumages and moults correspond but the female never acquires much blue, 

 remaining in a brown plumage like the male first winter. In first winter plumage 

 the female is pale cinnamon-brown darkest on the head and palest below and on 

 the rump; the wings and tail deep olive-brown; the wing bands pale chestnut, 

 the one at tips of greater coverts paler. The first nuptial plumage, assumed 

 almost wholly by wear, is paler, the brown fading. The adult winter plumage 

 usually shows a bluish tint in the wing edgings, the wings and tail being darker 

 than in first winter dress. More mature birds may show blue feathers on the 

 rump, crown, sides of head, sides of throat and across the jugulum but do not 

 often acquire a plumage as bright as that of the male in first nuptial plumage. 



Food. — Based on a study of the contents of 51 stomachs of the blue 

 grosbeak, W. L. McAtee (1908) reports that the food consisted of 

 67.6 percent animal matter and 32.4 percent vegetable. The stom- 

 achs of 13 young birds, still being fed by their parents, were included 

 in the study; in these the animal matter amounted to 99.08 percent, 

 of which grasshoppers constituted 74.1 percent. "The remains of as 

 many as 16 short-horned locusts were obtained from one stomach, 

 while another contained 14. Caterpillars, among them the purslane 



