BIRDS OP 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, swainsoni 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. 



Family : The Falcons, Hawks, Eagles, etc. 



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 X 1.91. 



This species is variously known as "Rough-legged 

 Buzzard," " California Squirrel-Hawk," or " Prairie 



