BIRDS OF PREY 153 
In the nest, they are fed upon small mammals and, even 
before their down has changed to feathers, they will tear 
their food with all the ferocity of a young puppy. 
The adults arrive from the South about the middle of 
March; by the middle of April they have constructed | 
their nest and are brooding their two or three eggs. 
Incubation requires twenty to twenty-two days, and the 
young remain in the nest from four to five weeks. One 
authority says eight, but this is a longer time than any 
of my own records show, and is, I believe, unusual. 
In flight, sewainsoni seems a trifle clumsy as he rises 
from the ground with a good-sized gopher in his claws ; 
but, as he swings into full headway, you realize that, like 
all his family, he is both swift and graceful on the wing. 
348. FERRUGINOUS ROUGH-LEG. — Archibuteo 
ferrugineus. 
Famity : The Falcons, Hawks, Eagles, ete. 
Length: Male 22.50; female 24.00. 
Adults, Normal Phase: Upper parts and flanks bright rufous ; under 
parts white, lightly streaked with brown ; tail white, tinged with 
rufous and sometimes banded with dark. 
Adult, Melanistic Phase: Upper parts dark brown marked with rusty; 
under parts dull rufous. 
Young: Upper parts grayish brown, feathers edged with rusty ; tail 
white at upper third ; rest brownish, banded with dark. 
Geographical Distribution : From Dakota and Texas to Pacific. 
Breeding Range: In California, the interior, west of the Sierra Nevada 
from Sacramento to San Diego. 
Breeding Season: April and May. 
Nest : Of sticks ; lined with leaves, grass, and rootlets. 
Eggs: 2 to 5; greenish buffy, marked with shades of brown and purple. 
Size 2.43 < 1.91. 
THIS species is variously known as “ Rough-legged 
Buzzard,” “ California Squirrel-Hawk,” or “ Prairie 
