Physical factors affecting pika density and dispersal

Publication Type:

Journal Article

Authors:

Bunnell, S. D.; Johnson, Donald R.

Source:

Journal of Mammalogy, American Society of Mammalogists, Volume 55, Issue 4, p.866-869 (1974)

Call Number:

A74BUN01IDUS

Keywords:

American pika, Ochotona princeps

Abstract:

Pikas (Ochotona princeps) are widely distributed in scattered colonies throughout the mountainous parts of the western United States and Canada where they occupy rock slides, lava flows, and occasionally slab piles left by sawmill operations. Field workers have reported that pikas are sometimes absent from what appears to be suitable habitat near existing colonies. We have made similar observations in northern Idaho and northeastern Washington where pikas occur in isolated rockslides at elevations exceeding 3600 feet (1200 meters). In an effort to determine the effects of certain physical factors on pika density, we have censused populations and measured four physical characteristics of nine small rockslides on St. Joe Baldy, Benewah County, Idaho, over a four-year period (1969 to 1972). We have also experimentally introduced pikas at two sites which lacked colonies in order to determine if some factor other than their remote location prevented colonization.