The western United States has experienced large-scale degradation due to land use and land cover changes, invasion of annual grasses, and expansion of woody plants into grass and shrublands and the resultant altered fire regimes. These landscape-scale changes have coincided with declining mule deer (Odocoileus hemionus) populations, making habitat loss...
North American bighorn sheep (Ovis canadensis) have experienced significant declines and population extirpations due to novel pathogens such as Mycoplasma ovipneumoniae. This disease continues to limit the population restoration of bighorn sheep. Therefore, understanding the demographic consequences of pathogen presence and the risk of contact between bighorn populations and potential...
Caspian terns (Hydroprogne caspia) and double-crested cormorants
(Phalacrocorax auritus) nest in large colonies on East Sand Island in the Columbia
River estuary, the largest known colonies for the two species in the world. Both
species of piscivorous colonial waterbirds have been identified as predators with a
significant impact on the...
Forage availability, diets, distribution, and productivity were
compared for Roosevelt elk, Cervus elaphus roosevelti, using improved
(i.e. seeded, fertilized, and grazed) and untreated areas of the Oregon
Coast Range. Seasonal forage availability was substantially different
on 1-year-old improved and untreated clearcuts, but the differences
diminished by clearcut age 4 and...
I investigated Caspian terns (Sterna caspia) breeding at colonies on the Columbia Plateau (southeastern Washington and northeastern Oregon), with emphasis on the breeding and foraging ecology of Caspian terns nesting at colonies in the mid-Columbia River. I focused research at colonies where Caspian terns foraged on juvenile salmonids (Oncorhynchus spp.)...
This is an investigative, descriptive study that explored fishing regulation conflicts between commercial fishermen and fishery resource management agencies. The purpose of the study was to develop a rich picture of the conflict phenomenon and apply sociological theory in order to illuminate the underlying structures and functions which contribute to...
Despite the belief that fuels management, a form of prescribed fire that reduces accumulated fuels in commercially thinned forests, is necessary to restore forest 'health' in the Pacific Northwest, its effects on wildlife has received little attention in the scientific literature. Because fuels management is supported, funded, and implemented nationwide...
Greater Sage-Grouse (Centrocercus urophasianus) have experienced declines throughout their range over the last 50 years. Long-term declines in sage-grouse abundance in Nevada and Oregon have been attributed to reduced productivity. From 1995-1997, sage-grouse production on Sheldon National Wildlife Refuge (SNWR), Nevada was greater compared to Hart Mountain National Antelope Refuge...
Forest managers are challenged to provide timber revenues and other resources for society while protecting and enhancing components of biodiversity that are often associated with older forests or older forest structure, such as dead wood. We examined small mammal response to timber harvest in stands 8-10 years following group-selection, two-story,...
No studies have evaluated the effects of limited vehicle access on movements, survival and habitat use of Roosevelt
elk (Cervus elaphus roosevelti) . We installed twenty gates, restricting motorized vehicle access by the public in
seven discrete Road Management Areas (RMAs), comprising 35% of the study area. We radio-tracked 31...