178 Birds of Colorado 



instance was noticed by A. S. Bennett at Lay in Routt 

 CO., July 10th, 1889 (Fisher). In this case they were 

 engaged in feeding on locusts. 



The nest, accordhig to Gale, is generally placed in a 

 cotton -wood tree, about twenty- five to fifty feet above 

 the ground. It is made of twigs and lined with a little 

 grass or strips of pine bark. The eggs, usually three 

 according to Gale, two according to Bendire, are faintly 

 greenish, and are as a rule very lightly spotted and 

 marked with reddish-brown. They average 2-25 x 1'7. 

 The old nest is generally occupied year after year. Gale 

 found fresh eggs from May 15th to 30th. Dille gives 

 June 5th. 



Genus ARCHIBUTEO. 



Very similar to Buteo, but with the tarsus feathered to the base 

 of the toes ; usually four outer primaries emarginate on the inner web ; 

 melanism very common. 



A small section of the Buzzards, with representatives in the northern 

 parts of the Old and New Worlds ; two species in the United States. 



Key of the Species. 



A. BiU smaller and weaker, chord of the cuhnen and cere about 1-2 ; 



belly with a patch of black in the normal phase. 



A. 1. sancti-johannis, p. 178. 



B. Bill stouter and stronger, chord of the cubnen and cere about 



1-6. thighs rufous with black cross-bands in normal phase. 



A. ferrugineus, p. 179. 



American Rough-legged Hawk. 

 Archibuteo lagopus sancti-johannis. 



A.O.U. Checklist no 347a — Colorado Records — Ridgway 73, p. 186 ; 

 Henshaw 75, p. 425 ; Drew 85, p. 17 ; Morrison 89, p. 8 ; Nash 96, p. 15 ; 

 Cooke 97, p. 75. 



Description. — Pltunago very variable — in the normal light phase, 

 mingled white, dusky brown and black above, white prevailing on the 

 head, the upper tail-coverts and the inner webs of tho primaries above 

 the notch ; tail chiefly white, with two or three transverse black bands 

 and a white tip ; below mottled white and dusky, sometimes with a 



