Red tree voles (Arborimus longicaudus) are a unique species of Arvicoline rodent found in western Oregon and northwest California. Their preferred habitat is mature and old-growth coniferous forest dominated by Douglas-fir (Pseudotsuga menziesii). Tree voles are an important prey item for northern spotted owls and many other predators, but are...
The combined effects of habitat loss, degradation, and fragmentation pose a serious threat to Earth's biodiversity, imperiling even relatively common species. 'Habitat' is necessarily a species-specific concept, and investigations of bird diversity relationships and subsequent efforts to prioritize conservation areas, are challenged by the difficulty of estimating complex habitat gradients...
From 1987-1997, Oregon State University conducted studies at Hart Mountain National Antelope Refuge (HMNAR) to better understand the relationship between grouse productivity and key habitat components. Early studies indicated sage grouse habitat preference and reproductive success were related to particular forbs (including legumes and milky juice composites) and structural characters...
Over-winter growth of juvenile salmonids may be linked to ocean survival and thus species persistence. Diet, growth, and prey available to juvenile coho, Oncorhynchus kisutch, were examined from December 2004 to April 2005 in four tributaries of the West Fork Smith River (WFSR), Oregon. Juvenile coho growth rate and condition...
This study describes streams in the Blue Mountains and Wallowa Mountains of Northeastern Oregon in order to characterize the interactions between the terrestrial and aquatic ecosystems and to determine how logging affects those relationships. Five stream reach pairs, each consisting of an undisturbed reach and a similar reach flowing through...
Since the early 1990s, declines in northern spotted owl (Strix occidentalis caurina) populations have been documented through extensive field surveys and range-wide demographic analyses. Although loss of late-successional forest has been credited as the primary cause for spotted owl population declines, environmental variation has also been shown to influence vital...
A trait based approach was used to assess impacts of overstory density and thinning on understory vegetation components related to wildlife habitat. The relationship between overstory basal area and understory vegetation for species grouped by traits, such as production of flowers, fleshy-fruit and palatable leaves, was characterized in thinned and...
Global Positioning System (GPS) and Geographic Information System (GIS) technologies were employed to evaluate cattle occupancy of three landscape attributes on three different grazing allotments administered by the Wallowa Whitman National Forest in Northeast Oregon. Topographic characteristics of slope; 0-4%, 4-12%, 12-35% and >35% were evaluated as well as north...
Pacific lamprey Entosphenus tridentatus is a valuable icon and traditional food source for Indigenous people of western North America. Native Americans have utilized traditional ecological knowledge (TEK) since time immemorial to guide their ways of life, transmitting cultural values and natural history to further generational knowledge. Pacific lamprey are in...
The American beaver (Castor canadensis) was nearly extirpated by the late 1800's due to the fur trade. Due to reintroduction efforts, it now occupies much of its former range. Beavers are a keystone species and ecosystem engineers, greatly influencing riparian and instream habitats through selective harvesting of plant materials and...