FIG. 23- 1 Left, montane forest 

 in Oregon — a virgin stand 

 of ponderosa pine. Below, 

 forest, tundra in northern 

 Manitoba, composed of spruce 

 and tamaracli with the ground 

 covered with a thick layer of 

 moss ond lichens (courtesy 

 W. P. Gillespie). 



Olive-sided flycatclier 

 Gray jay 

 Common raven 

 Red-breasted nuthatch 

 Brown creeper 

 Winter wren 

 Hermit thrush 

 Swainson's thrush 

 Golden-crowned kinglet 



Ruby-crowned kinglet 

 Solitary vireo 

 Nashville warbler 

 Wilson's warbler 

 Purple finch 

 Pine grosbeak 

 Pine siskin 

 Red crossbill 

 Lincoln's sparrow 



!\orth A meriran boreal forest bioriation 



This biociation extends from the Atlantic 

 Ocean to the Rocky Mountains in Canada and south 

 on the Appalachian Mountains to northern Georgia 

 (Shelford and Olson 1935. Kendeigh 1947, 1948, 

 Munroe 1956). There is a broad overlap or fusion 

 between the boreal and montane forest biociations in 

 the northern Rockies where species of one biociation 

 penetrate into the other (Rand 1945, Drury 1953). 

 Characteristic mammals that occur generally 

 through the boreal and pine-hemlock forests, in addi- 

 tion to those listed in the above section, are : 



Arctic shrew 

 Masked shrew 

 Smoky shrew 

 Pigmy shrew 

 Star-nosed mole 

 Hoary bat 

 Least chipmunk 

 Northern bog lemming 

 Capper's red-backed 



mouse 

 Ungava phenacomys 

 Rock vole 



Meadow jumping mouse 

 Woodland jumping 



mouse 

 American marten 

 Fisher 

 P'rmine 

 Least weasel 

 Wolverine 

 I .ynx 

 Moose 

 Woodland caribou 



Bird species found in this biociation are listed in 

 Table 23- L This biociation is especially notable for 

 the large representation of wood warblers in the avi- 

 fauna, each with its own specialized niche (Mac- 

 Arthur 1958). In northern Ontario, warblers con- 

 stitute 69 per cent of the breeding bird population 

 in the spruce-fir forest ; in northern Maine, 63 per 

 cent. 



As one proceeds south from Ontario and Maine 

 into Minnesota, Michigan, New York, and along the 

 Appalachian Mountains to Tennessee, species both 

 of mammals and birds drop out, apparently as they 

 reach limits of tolerance to climatic factors. Perhaps 



Coniferous forest, woodland, and chaparral biomes 303 



