26 EXPLORATIONS AND SURVEYS WEST OF 100TH MERIDIAN. 



fowl, and this undoubtedly explains in part the abundance of hawks 

 at this season, since wounded and disabled ducks must form no incon- 

 siderable part of their food. Its manner of hunting much resembles 

 the following species, and like it subsists to a certain extent upon mice, 

 which are very numerous in the rushes. In the stomachs of every indi- 

 vidual captured was found the remains of these little animals. 



Circus cyaneus, (L.), var. lindsonius L. Marsh-Hawk. 



Frequently observed in the lowlands during the trip nearly as abun- 

 dant as the preceding at Provo in the fall. To be seen at all hours of 

 the day, sweeping over the tops of the marsh-rushes in search of mice. 

 In several instances these birds were decoyed within gunshot by the 

 collector hiding in the rushes ancj ii^it^iHg the squeak of a mouse. 



Haliaetus leucoceplialus, (L.) Bald Eagle. 

 Of frequent occurrence in the lowlands. 



Aquila clirysaetos, (L.), var. 

 Of frequent occurrence in 



s-Ls-^Q olden Eagle. 



CATHARTID-E. 



Ehinogryplius aura, (L.) Turkey-Buzzard. 

 Very common throughout Nevada and Utah, but extremely shy. 



Pseudogryphus calif or nianus, (Shaw.) California Vulture. 



A very large vulture seen near Beaver November 25 was believed to 

 be of this species ; in company with the R. aura, which it greatly ex- 

 ceeded in size. It had just finished a repast upon the carcass of a horse. 



