33 
of the United States . 
hook ; lobe strongly marked ; edges of the lower mandible 
indexed ; cere not much extended, more or less pilose ; nos- 
trils oblong, transverse, covered in part by the hair ; lores 
pilose: head depressed: body slender. Tarsus elongated, 
slender, scutellated, feathered for a short space : toes rather 
long, slender ; outer toes connected at base : nails subequal, 
slender, much incurved, extremely sharp. Wings elonga- 
ted ; first primary shorter than the fifth ; third and fourth 
longest. Tail long, nearly even. 
Female and young differing considerably in colour from 
the male ; often with a kind of collar of small rigid feathers 
surrounding the face, as in Owls. Plumage changing extra- 
ordinarily from age. 
Bold : somewhat agile ; flight graceful ; in these respects 
superior to the Buteones, but inferior to the true Falcons. 
Do not chase well on the wing. Feed on mice, reptiles, 
fishes, young birds, and insects. Dwell near marshes and 
ponds. Build amongst marsh plants. 
21. Falco hyemalis, Gm. No collar round the face; wings 
when closed reaching but little beyond the middle of the tail. 
Adult brown skirted with ferruginous ; head, neck, tail 
coverts and beneath, white, spotted with brown ; tail barred 
alternately with dark and light brown. 
Young brown and ferruginous ; beneath rusty, varied 
with black and white ; wings and tail black, the former spot- 
ted, the latter crossed by five bands, and tipped with white. 
Winter Falcon , Falco hyemalis , Wils. Am. Orn. iv. p. 73. 
pi. 35. fig. 1. adult male ; and Red-shouldered Haivlc , Falco 
lineatus , Id. vi. p. 86. pi. 53 . fig. 3. young male. 
Inhabits North America : rather common in Pennsyl- 
vania during winter. 
22. Falco cyaneus,L. A collar round the face; wings 
