164 Birds of Colorado 



feeder and a scavenger, and in the south is a most valuable 

 aid to sanitation. When a carcass is found, the Buzzards 

 assemble and gorge themselves to repletion ; they retire 

 to a perch close by to roost and digest, and return again 

 and again until the bones are picked quite clean. 

 When in the air they sail and circle high with out- 

 spread wings, on the look-out for a meal. They have 

 no note or cry beyond a hissing, wheezy sound. 



Buzzards, though not usually gregarious, often use 

 a common roosting -place — Rockwell describes such a 

 roost in a grove of trees on Plateau Creek, where he 

 has seen as many as fifty of these birds assembled at 

 night time. Morrison found them breeding in the La 

 Plata mountains at an elevation of about 12,000 feet. 

 The nest was merely a ledge in the cleft of a broken 

 boulder on the mountain side ; there were two eggs of 

 a dirty-white colour, blotched with reddish -brown, 

 these measured 2"73 x 1"95 and 2*70 x 1"91 respectively. 

 The eggs were much soiled and the whole surroundings 

 of the spot loathsome and evil -smelling. Dennis Gale 

 is the other observer who has found the Buzzard breeding 

 in Colorado. He reports that he saw several nesting 

 in cotton-wood trees on the Little Thompson, with Blue 

 Herons. They were probably making use of the nests 

 of the Herons, though Gale, in his notes, does not dis- 

 tinctly say 80. This was on April 16th. 



Family FALCONID^. 



Head and neck never naked (in the New World forms) ; 

 bill generally stout, strong and hooked, with a cere or 

 soft cushion at the base within Avhich the nostrils open ; 

 nostrils never pervious ; wings with ten primaries, tail 

 of twelve rectrices with rare exceptions ; feet strong, 

 toes cleft or only webbed at the extreme base, the 



