18 WILD ANIMALS OF GLACIER NATIONAL PARK. 



The bird and mammal life of the park are too rich and varied to 

 be touched upon lightly, and each is Avorthy of a volume by itself. 

 In few other places on the continent can so great a variety of the 

 larger game animals be found close together. The moose, elk, mule 

 and Avhite-tail deer, mountain goat, mountain sheep, grizzly and 

 black bears, and the great hoary marmct are all common in parts 

 of the park, while many of the smaller mammals furnish constant 

 interest along the trails and about the hotels and camps. 



While certain areas are at times almost devoid of bird life, there 

 are always others where birds are abundant and where the songs 

 of the varied thrush, the olive-backed and western hermit thrushes, 

 the gray fox sparrow, the white-crowned sparrow, warblers, vireos, 

 wrens, and other choice songsters may be heard. Above timberline 

 the rosy finches and pipits breed, and mother ptarmigans lead about 

 their broods of downy young, while lower down the Franklin, Rich- 

 ardson, and rutfed grouse may be studied along the trails. A number 

 of water birds breed in the- lakes, and many of the. individuals are 

 becoming unafraid of man. The opj^ortunity for close bird study 

 is unusually favorable, and the bird life is as full and varied as in 

 any part of the Rocky Mountain region. 



Most of the streams are well stocked, and many afford excellent 

 trout fishing. In the larger lakes and streams the trout are large 

 and gamey, while in the smaller streams their abundance usually 

 compensates for their smaller size. 



Reptiles and amphibians are generally scarce in the park, but two 

 species of small garter snakes are found, and several species of frogs 

 and toads are connnon. 



II. LIFE ZONES. 



The plants and animals of the park are distributed in a series of 

 approximately horizontal belts or zones, but on such broken slopes 

 that only by a broad view can the zonal arrangement be recognized. 

 Four of the transcontinental life zones are represented, the Transi- 

 tion, Canadian, Iludsonian, and Arctic-Alpine, ranging from the 

 basal slopes upward, each with its characteristic set of mammals, 

 birds, and plants. The boundaries of these belts are not sharply de- 

 fined, and each zone merges into those adjoining in a way that at times 

 is confusing, but the conformity of certain sets of species to certain 

 limits of altitude is apparent to the most superficial observer. That 

 these limits are due to climatic conditions dependent largely upon 

 altitude and slope exposure is also apparent when the evidence is 

 considered. 



The natural grouping and arrangement of the plant and animal life 

 of the park can be best understood on the basis of the common laws 

 of distribution. Certain species are adapted to a restricted range of 



