1921 BIRDS OF MONTANA 21 



ill this association, and in the mountain foothills I have found nests of the West- 

 ern ('hipping Sparrow and Pink-sided Juneo in sage-covered areas. 



The wild-rose association consists of thickets of shrubs that occur on the 

 sides of moist coulees on the prairies and a])out the foothills of the mountains. 

 While the wild-rose is one of the most abundant shrubs, many others are found, 

 such as currant and gooseberry (Kibes), buffalo-berry (Shepherdia) , silver berry 

 {Elcagnus), snowberry (SympJioricarpus) , and thorn (Crataegus). The most 

 characteristic species of this association are the Wright Flycatcher, ]\Iagpie, 

 Brewer Blackbird, Clay-colored Sparrow, Arctic and Green-tailed towhees. Lazuli 

 Bunting, IMacGillivray Warbler, Western Yellowthroat and Catbird. 



The cinquefoil association is found mainly in the northwestern prairie re- 

 gion, where sage-brush areas do not occur. It consists of low scattered bushes of 

 the shrubby cinquefoil (Dasiophora fruticosa) , forming a growth that very much 

 resembles sage. A few other shrubs, such as the buffalo-berry and silver berry, 

 are found in small quantity with it. Its birds are the ]\Iarsh Hawk', Short-eared 

 Owl, Sharp-tailed Grouse, Brewer Blackbird, Vesper Sparrow, Clay-colored Spar- 

 row, and certain others. There being often bodies of water close by. ducks occa- 

 sionally nest in this association. jMany species which live upon tiie open grass 

 areas of the prairie are liable to place their nests in this association because of 

 the protection the shrubs afford. 



Tree associations cover a larger part of the area of the state than any other 

 group except the grass associations. They support a larger amouni: of bird life 

 per unit of area than the grass associations and are therefore of greater import- 

 ance in their influence on bird distribution. We may make two general divisions 

 of the tree associations, broad-leaf trees and coniferous trees, though there is at 

 least one well-marked association, west of the continental divide, that is a mixture 

 of both. The broad-leaf tree associations are but two in number, cottonwood 

 groves and aspen groves. 



Cottonwoods are found along streams in the Upper Sonoran and Transition 

 zones, mainly in the prairies and mountain valleys. (See fig. 3.) Four species of 

 Populus are represented, P. deltoidcs in the eastern part of the state, P. balsam- 

 ifera and P. angustifoUa throughout most of the state, and P. tricJiocaypa west of 

 the divide. While these species are the only trees, there is a considerable under- 

 growth of young cottonwood, willows, dogwood (Corniis stolonif'Ta) and other 

 shrubs. There are many species of birds breeding in this association, and bird life 

 is usually abundant in it, particularly in small groves that occur at long intervals 

 in prairie regions. Some of the most characteristic species are the Swainson 

 Ilawk, Horned Owl, Red-shafted Flicker, Kingbird, Western Kingbird, Western 

 Wood Pewee, Least Flycatcher, Magpie, Crow, Bullock Oriole, Goldfinch, Cedar 

 Wax wing, Red-eyed Vireo, Yellow Warbler, Redstart, House W>en, Long-tailed 

 Chickadee and Robin. 



The aspen grove is found chiefly in the lower mountains in the western half 

 of the state, occupying the Transition and lower Canadian zones. It consists 

 almost entirely of the aspen (Populus tremuloides) , which forms small groves 

 in somewhat moist soil in the lower mountains. The area of this association is 

 not great, but there are a few species of birds that are characteristic of it and in 



