Great Basin Naturalist


Rodent trapping was conducted in representative northern Great Basin habitat types for six consecutive years to determine the magnitude of density change, the specific habitat affinities, and the effects of habitat alteration on rodent density. Although species responded differently, total rodent density was greater in depleted shadscale and sagebrush communities than in comparable pristine sites. However, disturbed sites with nearly pure stands of weedy introduced annuals supported few rodents. Several species exhibited abrupt and concurrent yearly changes in density. The factors causing these changes were not identified. Until this information is available, we can develop only crude models to predict the direction and magnitude of population change.