78 Wyoming Experiment Station. 



360 a. Falco sparverius deserticolus Mearns. 

 Desert Sparrow Hawk. 



Summer resident arid very common. They arrive on the 

 Laramie plains as early as March 29th, and are quite common 

 by the middle of April. Their food is identical with the prev- 

 ious species, and what Fisher has said of that species refers to 

 this western form, with the exception that the great difiEerence 

 in environment would make some slight changes. 



I have taken this variety at the following places : Sand 

 creek, Albany county ; Button's lake, Buffalo, Otto, Chug- 

 water, Evanston, Green river. South Pass and Ervay. There 

 is a single skin in the University collection. 



364. Pandion haliaetus carolinensis (Gmsl.). 

 American Osprey. 



Summer resident and common in suitable localities. 

 Known to be only along wooded streams, where the trees are 

 of considerable size and the stream abounds with fish. With 

 the exception of this bird feeding upon fish, there can be no 

 possible objections to it. In Wyoming they feed largely upon 

 trout, which are so abundant. I have found these birds most 

 numerous along the Big Wind, Gros Ventre, and Snake riv- 

 ers, while in Jackson's Hole in 1894 I killed three of these 

 birds and prepared their skins ; but these, together with all 

 other collections, were consumed by fire while in transit on 

 the Union Pacific railroad. One of these birds was killed as 

 it was about to light on a nest in the very top of a dead spruce 

 tree. It had capturd a trout weighing about a pound, which I 

 secured. 



Jesurun reports these birds common at Douglas; Bond 

 has taken them at Cheyenne; Coues reports one specimen 

 from the Wind river; Grinnell makes the following state- 

 ments: "Nowhere as abundant as on the Yellowstone river. 

 Saw from 6 to 12 birds every day. At the falls of the Yellow- 

 stone this species was constantly in sight;" Drexel reports 

 a single specimen taken at Fort Bridger, 1858. 



