62 BULLETIN FERGUS COUNTY HIGH SCHOOL 



back of Crowley's ranch near town. The forager was first noticed flying in- 

 to the top of a cottonwood tree. It had scarcely settled, however, when 

 it flew down to the edge of the creek bank, not twenty feet from me, 

 seized a mouse venturing out of its burrow, and after a sharp squeak by 

 the victim, the shrike returned to the tree with its prey. I was surprised 

 &.t the power of vision of the shrike, and at the display of audacity in thus 

 picking up its victim almost under my feet. 



Distinguishing features: Upper parts ashy gray, with shoulders, 

 rump, and upper tail coverts lighter; sides of head marked with black; 

 lower parts white, breast and sides barred with gray; length 10-11 inches. 

 622a. WHITE-RUMPED SHRIKE. Lanius ludovicianus excubitorides. 



This shrike is not uncommon as a summer resident of this region. 

 Dr. J. A. Allen states that a few pairs were met with, widely scattered 

 throughout the whole district traversed by the expedition. Dr. C. E. Mc- 

 Chesney says that in the Big Horn region this shrike was observed in the 

 mountains in some numbers. Dr. Elliott Coues reported that along the 

 northern boundary of the state, the white-rumped shrike was common 

 in suitable localities. Capt. Platte M. Thome reports this species as rare 

 at Ft. Keogh. Messrs. Richmond and Knowlton note that this shrike is 

 common in the valleys in south-central Montana. 



Distinguishing features: Like the northern shrike, but smaller, 

 length 8-10 inches; sides but faintly tinged with gray. 



624. RED-EYED VIREO. Vireo olivaceus. 



One of the common summer birds of the region. It inhabits the 

 deciduous groves in the bottomlands of the larger streams, associating 

 with yellow warbler, catbird, black-headed grosbeak, and birds of similar 

 resorts. Its nest is placed in a drooping fork near the extremity of a 

 branch, being attached to the twigs by its brim. 



Distinguishing features: Upper parts olive-green; lower parts light- 

 er; length about 6 inches. 



627. WARBLING VIREO. Vireo gilvus. 



A regular summer resident in suitable localities. Among the haw 

 and willow thickets this vocalist can be seen and heard, spending its time 

 in gleaning its insect fare from the foliage, or caring for its household 

 a swing in the fork of some low-bending twig. The female warbling vireo 

 has a pretty habit of sitting in her nest and singing in response to her 

 mate. 



The nests of the vireos are worthy of special mention. They are 

 always suspended by the brim in a small fork of a slightly drooping 

 branch. The exterior walls of the swinging habitation are made of strips 

 of pliant bark, with which are interwoven shreds of birch bark, bits of 

 gossamer, and scraps of hornet paper. The nest is lined with fine dried 

 grass. The eggs are delicately white, with dots and specks of blackish 

 brown. 



Distinguishing features: Upper parts olive-gray, tinged with green- 

 ish on rump and upper tail coverts; white streak over eye; lower part* 

 white, tinged with yellow; length about 5 inches. 



