Wyoming Birds. 43 



FALCONIDAE (The Falcons). 



Of the Falcons which we have with us in Wyoming, the two 

 most important are the Prairie Falcon and the Sparrow Hawk. 

 The former are actively engaged in catching small mammals and 

 some small birds. The latter confine themselves largely to mice 

 and the larger insects, such as grasshoppers, crickets and butter- 

 flies. 



References : 



1. Biological Survey Bulletin No. 61. 



355. Falco mexicanus: Prairie Falcon. 



Fairly common over most of the southern part of the state. 



356a. Falco peregrinus anatum: Duck Hawk. 



Rather rare. Since Knight's book was published, Metz and 

 Lockwood are the only observers who have noted it. "This 

 vicious falcon has been observed by only two collectors in 

 Wyoming, and these observations were made over a quarter 

 of a century ago.'' (Knight.) 



357. Falco columbarius columbarius: Pigeon Hawk. 



In the Big Horns, Blackwelder saw what he thought was 

 this bird. Metz records it and Blackwelder again noted it 

 in the Teton region. "Migratory ; rare ; possibly may breed 

 in the alpine regions. We know nothing of this blood- 

 thirsty hawk." (Knight.) 



357b. Falco columbarius richardsoni: Richardson's Pigeon Hawk. 

 Found mainly in southern Wyoming, probably a summer 

 resident. But there are no breeding records. Walker took 

 two specimens at Green River in September, 1910. See 

 also Lockwood. 



360. Falco sparverius sparverius: Sparrow Hawk. 



The records of this and phalaena are badly confused. Un- 

 doubtedly the two species mingle in this state. One or the 

 other occurs over the entire state at all the lower altitudes. 

 Repored by Blackwelder, Richard and Clearwaters. 



360a. Falco sparverius phalaena: Desert Sparrow Hawk. 



Reported by Blackwelder, Metz, Peabody and Clearwaters. 



