20 University of Michigan 



]Mount Sischu to occur just above a white spruce-paper birch 

 forest where this reached timber-line on a steep slope. 



This habitat is somewhat more exposed to the winds than the 

 lowland willow-alder habitat, and the species of animals in the 

 habitats surrounding it differ to some extent from those of 

 the habitats surrounding the lowland habitat. Yet, with a few 

 apparent exceptions, the species found in the willows and 

 alders are the same above timber-line as in the bottoms of the 

 valleys. 



Blueberry-dwarJ birch habitat and association: 



Canachites canadensis osgoodi. .\laska spruce grouse. Resident. 

 Lagopus lagopHS albiis. Willow ptarmigan. Resident. 

 Lagopus rupestris riipestris. Rock ptarmigan. Resident. 

 Pedioecetes phasiancUus phasianellus. Sharp-tailed grouse. Winter. 

 Asio flammeus. Short-eared owl. Summer (Osgood). 

 Siirnia uliila caparoch. Hawk owl. Resident. 

 Acanlhis linaria linaria. Redpoll. W'inter. 



Passcrcidiis sandunchensis alaudinus. Western savanna sparrow. Sum- 

 mer. 

 Planesticus migraioriiis migratorius. Eastern robin. Summer. 

 Ursus americanus americamis. Black bear. Summer. 

 Vulpes alascensis alascensis. Alaska red fox. 

 Maries americana actnosa. .\laska marten. 

 Miislela arctica arclica. .\rctic weasel. 

 Evotomys dawsoni dawsoni. Dawson red-backed vole. 



A thick growth of low shrubs is commonly found in the open 

 parts of the valleys, but especially on the hills just above timber- 

 line. These shrubs are the common ones found in the black spruce 

 forests, here growing more closely together and forming more of a 

 thicket. The dominant species are the blueberries, Vaccinnum, 

 and dwarf birch, Betula glandulosa. Other common species are 

 the dwarf willows, Salix, dwarf alders, Alnus, and Labrador tea. 

 Ledum. Clumps of the niggerhead grass are often abundant, and 

 occasional small, stunted black spruces occur. The ground is 

 usually heavily covered by sphagnum, with which is frequently 

 growing reindeer "moss," Cladonia rangiferina. 



