76 Wyoming Experiment Station. 



360. Falco sparverius Linn. 



v American Sparrow Hawk. 



There is no doubt but that this species and Desert Sparrow 

 Hawk mingle in eastern Wyoming and on this account there 

 is no possible way by which the early records can be adjusted, 

 unless the specimens can be found. On this account I have 

 placed nearly all of the Wyoming records under the American 

 Sparrow Hawk; but fully realizing that many of them be- 

 long to the succeeding, variety. In accordance with the re- 

 striction placed upon the range of these two birds, the Desert 

 Sparrow Hawk is the one that should be found in greatest 

 abundance and inhabiting by far the greater portion of the 

 state. The Sparrow Hawk is everywhere abundant, below 

 the alpine districts, and is especially so in the valleys and on 

 the plateaus. They occur in vast numbers where the only 

 resting place they find is a wire fence. They are a great 

 friend to the ranchman and farmer and depend largely upon 

 insects and mice for their food. Fisher (Hawks and Owls 

 of the United States, pp. 116-119) has the following to say 

 of these birds : 



"The subject of the food of this Hawk is one of great 

 interest, and considered in its economic bearings is one that 

 should be carefully studied. The Sparrow Hawk is -almost 

 exclusively insectivorous except when insect food is difficult 

 to obtain. In localities where grasshoppers and crickets are 

 abundant these hawks congregate, often in moderate-sized 

 flocks, and gorge themselves continuously. Rarely do they 

 touch any other form of food until, either by the advancing 

 season or other natural causes, the grasshopper crop is so 

 lessened that their hunger can not be appeased without un- 

 due exertion. Then other kinds of insects and other forms 

 of life contribute to their fare ; and beetles, spiders, mice, 

 shrews, small snakes, lizards, or even birds may be required 

 to bring up the balance. In some places in the West and 

 South telegraph lines pass for miles through treeless plains 



