1921 BIRDS OF MONTANA 15 



them that faunal and zonal areas are composed. The immediate, local distribu- 

 tion of life in a given locality is determined by the associations. We may classify 

 all associations conveniently as follows: Grass associations, water associations, 

 rocks, shrubs, trees, and artificial associations, the latter produced by the pres- 

 ence of buildings, bridges arid other similar man-provided structures. 



Grass associations may be divided into three main kinds, meadows, benches 

 and foothills. A more detailed study would undoubtedly show many more than 

 this, particularly if the study. were concerned with the distribution of some other 

 class of animals than birds. These three, however, are the main ones, most easily 

 recognizable, and most distinct in the bird species inhabiting them. 



Meadows are lands that are near streams and that are moist in soil, though 

 seldom wet or swampy. They are agricultural in character, and the greater part 

 of them are now under cultivation, or cut over for hay each year. They are 

 clothed with tall wild grasses of such genera as CaJamagrostis and Festuca, and. 



Fig. 2. Priest Butte, Teton County; Maech, 1912. Transition Zone. The 



VIEW illustrates grass benches, a prairie lake and a BUTTE. 



where cultivated, Phlenm and Agrostis. The characteristic breeding birds are 

 Sharp-tailed Grouse, Bobolink, Meadowlark, and Savannah Sparrow. This asso- 

 ciation occurs mainly in the Upper Sonoran and Transition Zones, but I have 

 seen large areas of it in the Canadian in. some places. The most conspicuous of 

 these isolated tracts is in White-tail Park, in Jefferson County, at an elevation 

 of 7,100 feet, where the above named birds, supposedly Transition species, breed 

 in meadows that are surrounded by lodgepole pines and spruces, tlie forests of 

 these trees being inhabited by true Canadian species, such as Franklin Grouse 

 and Mountain Chickadee. 



In portions of the prairie region the meadows are alkaline in character, and 

 form a somewhat different association. These areas are usually about the bor- 

 ders of alkaline ponds or in hollows in the prairies, where temporary ponds are 

 liable to occur in wet weather. The grasses are shorter and coarser than in the 



