THE HUDSONIAN AND CANADIAN ZONES. 19 



musk ox, and barren-ground caribou or reindeer, are characteristic 

 animals. Within the United States the Arctic- Alpine zone is restricted 

 to the area above timber-line on the summits of high mountains. It 

 is inhabited by arctic-alpine plants and animals, and is far too cold 

 for agriculture. 



2. THE HUDSONIAN ZONE. 



The Hudsonian zone comprises the northern part of the great trans- 

 continental coniferous forest — a forest of spruces and firs stretching 

 from Labrador to Alaska — and the upper timbered slopes of the higher 

 mountains of the United States and Mexico. In the north it is inhab- 

 ited by the wolverine, woodland caribou, moose, rough-legged hawk, 

 great gray owl, great northern shrike, pine bullfinch, white-winged 

 crossbill, white-crowned sparrow, and fox sparrow. In the eastern 

 United States the Hudsonian zone is restricted to the cold summits of 

 the highest mountains, where it occurs in the form of a chain of widely 

 separated islands reaching from northern New England to western 

 North Carolina. In the western United States it covers the higher 

 slopes of the Rocky Mountains and the Sierra-Cascade system, and is 

 the home of the mountain goat, mountain sheep, coney or pika, alpine 

 fiying squirrel, Clark's crow or nutcracker, evening grosbeak, and 

 Townsend's solitaire. Like the preceding, this zone is of no agricul- 

 tural importance. 



3. THE CANADIAN ZONE. 



The Canadian zone comprises the southern pai't of the great trans- 

 continental coniferous forest of Canada, the northern parts of Maine, 

 New Hampshire, and Michigan, a strip along the Pacific coast reach- 

 ing as far south at least as Cape Mendocino in California, and the 

 greater i)art of the high mountains of the United States and Mexico. 

 In the East it covers the Green Mountains, Adirondacks, and Catskills, 

 and the higher mountains of Pennsylvania, West Virginia, Virginia, 

 western North Carolina, and eastern Tennessee. In the mountains of 

 the West it covers the lower slopes in the north and the higher slopes 

 in the south. In the Rocky Mountain region it appears to reach con- 

 tinuously from British Columbia to west central Wyoming; and in the 

 Cascade Range, from British Columbia to southern Oregon, with a nar- 

 row interruption along the Columbia River. Among the many charac- 

 teristic mammals and birds of the Canadian zone are the lynx, marten, 

 porcupine, northern red and pine squirrels, varying and vSnowshoe 

 rabbits, star nose. Brewer's and Gibb's moles, water shrew, voles, 

 and long-tailed shrews of various species, northern jumping mice, 

 Belding's and Kennicott's ground squirrels, white-throated sparrow, 

 Blackburn ian, yellow-rumped, and Audubon's warblers, olive-backed 

 thrush, three-toed woodpeckers, spruce and dusky grouse, crossbills, 

 and Canada jays. Counting from the north, this zone is the first of 

 any agricultural importance. Wild berries — as currants, huckleber- 



