Occasional Papers of the Museum of Zoology 21 



Bare-ridge habitat and association: 



Lagopiis lagopus alhus. Willow ptarmigan. Resident. 

 Lagopus rupeslris rupestris. Rock ptarmigan. Resident. 

 Stirnia uliila caparoch. Hawk owl. Winter. 

 Otocoris alpestris arcticola. Pallid horned lark. Summer. 

 Leucosticte tephrocotis. Gray-crowned rosy finch. Summer (Blackwelder) . 

 Calcarius lapponicus alascensis. Alaska longspur. Summer (Osgood) . 

 Calcarlus pictus. Painted longspur. Summer (Blackwelder). 

 Passerculus sandwichensis alandinus. Western savanna sparrow. Sum- 

 mer (Blackwelder). 

 Anthiis spinoletta rubescens. Pipit. Summer. 

 Saxicola cenanlhe cenanthe. Wheatear. Summer (Blackwelder). 

 Ursus phaonyx. Tanana grizzly. Summer (Osgood). 

 Evotomys dawsoni dawsoni. Dawson red-backed vole. 

 Microtus pennsylvanicus drummondi. Drummond vole. 

 Microtus operarius endxciis. Interior vole (Osgood). 

 Rangifer stonei. Stone caribou. 

 Ovis dalli. Dall sheep (Osgood). 



On the ridges and slopes of the higher hills or mountains where 

 the ground is not covered by rocks there is either a sparse growth 

 of grass or of sphagnum moss. The grass is found in the more 

 swampy situations, such as at the head of a cove, while the moss 

 covers the drier slopes. On Mount Sischu at an estimated eleva- 

 tion of 2,500 feet the blueberries and other shrubs almost disappear, 

 and the slopes above are carpeted with a thin covering of moss, 

 through which small loose rocks often project. A few very low 

 shrubs occur at intervals, and sometimes small patches of bare 

 ground appear. 



Rocky-slope habitat and association: 



Lagopus rupestris rupestris. Rock ptarmigan. Resident. 

 Otocoris alpestris arcticola. Pallid horned lark. Summer. 

 Leucosticte tephrocotis. Gray-crowned rosy finch. Summer (Osgood). 

 Saxicola cenanthe oenanthe. Wheatear. Summer (Osgood). 

 Mustela arctica arctica. Arctic weasel (Osgood). 

 Marmola caligata caligata. Hoary marmot (Osgood). 

 Ochotona collaris. Collared pika (Osgood). 

 Ovis dalli. Dall sheep (Osgood) . 



A few talus slopes occur on the higher parts of the mountains 

 of interior Alaska. Some of the slopes are of considerable extent, 



