68 Wyoming Birds. 



residents in the mountains, which would indicate that they 

 breed there. Metz, Peabody, and Percival also report it. 



619. Bombycilla cedrorum: Cedar Waxiwing. 



Common resident in portions of the state. Metz, Black- 

 welder, and Clearwaters record it. 



LANIIDAE (Shrikes). 

 The Shrikes arc flesh eaters exclusively, their food consisting 

 of grasshopjers, beetles, mice, and sparrows. During the summer 

 months 75 per cent of the food of the Loggerhead Shrike consists 

 of grasshoppers. During the winter months they feed upon birds 

 and mice. On the whole, the Shrikes are considered beneficial. 



References : , 



1. Year Book of the Department of Agriculture, 1900, pp. 300- 



302 and 416-417. 



2. Biological Survey Bulletin No. 9, pp. 15-25. 



621. Lanius borealis: Northern Shrike. 

 Common winter resident. 



622a. Lanius ludovicianus excubitorides: White-rumped Shrike. 

 Common summer resident over most of the state. 



VIREONIDAE (Vireos). 



The Vireos- are among the most valuable insect destroyers. 

 They are fond of caterpillars and the larvae of beetles which de- 

 foliate the trees. They also feed upon aphids and various species 

 of beetles, bugs, and orthoptera. Some wild fruits are eaten also. 



The Western Warbling Vireo is the only member of the family 

 that is abundant in this state. It feeds almost exclusively upon 

 insects that it finds on the aspens and trees of the foothills and along 

 the streams. 



References : 



1. Biological Survey Bulletin No. 30, pp. 39-40. 



2. Year Book of the Department of Agriculture. 1906, pp. 194- 



195. 



3. Year Book of the Department of Agriculture, 1900, p. 416. 



4. '-Useful Birds and Their Protection," Forebush, pp. 203-208. 



