112 BULLETIN 17 0, UNITED STATES NATIONAL MUSEUM 



central feathers, there is more black-and-white banding on the lateral 

 feathers, the subterminal black band is broader, and there is a broad 

 terminal band of "pinkish cinnamon"; the head markings are much 

 as in the adult; the chin and throat are white, unmarked; the rest of 

 the under parts is "pinkish buff", narrowly streaked on the breast and 

 belly, and heavily spotted on the flanks with black. 



In the young female the resemblance to the adult female is even 

 closer. The mantle and wings are like the adult, but the brown is 

 duller, "vinaceous-russet", and the black bars are broader than the 

 brown spaces; the tail is like that of the adult female, but the black 

 bars are broader; the under parts, except the white chin and throat, 

 are "pale pinkish buff", heavily streaked on the breast and flanks 

 with "sepia" or "bister." 



These ju venal plumages are worn through summer, but early in fall 

 changes begin to take place, by fading and by a gradual molt of the 

 body plumage, during September and October; by midwinter great 

 progress has been made toward maturity. 



During the first fall young birds have a restricted rufous crown 

 patch, with black shaft streaks, which gradually increases and clears. 



Meantime, young males become whiter below and some begin to 

 acquire the cinnamon breast, but they are still heavily barred on the 

 back and heavily spotted on the breast. Both of these sets of mark- 

 ings partially disappear by molt during the first winter, but young 

 birds always retain some of these markings, as well as the juvenal 

 tail, until the next complete, annual molt in September and October. 

 Similar progressive changes occur in young females; paler colors are 

 acquired below, with paler and narrower streaks, and narrower, 

 dark bars on the mantle. 



Adults have a complete annual molt, mainly in September and 

 October. I believe that the full perfection of plumage is not acquired 

 until the bird is two years old, or more. The oldest males have the 

 least spotting on the scapulars, a clear white or cinnamon breast, 

 with only a few round black spots on the flanks, and the most rufous 

 in the tail ; probably successive annual molts are required to reach this 

 perfection. There is a decided seasonal change in appearance, due 

 to wear and fading; the colors are deeper and richer in the freshly 

 molted, fall and winter plumage than in the worn and faded condition 

 of spring and summer. This is especially noticeable in birds from 

 the desert regions.] 



Food. — The food of the sparrow hawk includes insects, birds, 

 mammals, reptiles, and amphibians. Its diet varies considerably 

 according to season and locality ; hence the contents of a bird's stomach 

 often indicates merely local or temporary conditions. Where grass- 

 hoppers abound, they make up the hawk's principal food, birds being 



