Publications

In many permanent ponds throughout western North America, the introduction of a variety of exotic fish and bullfrogs (Rana catesbeiana) correlates with declines in native amphibians. Direct effects of exotics are suspected to be responsible for the rarity of some native amphibians and are one hypothesis to explain the prevalence of amphibian declines in western North America. However...

No abstract available.

No abstract available.

stimates of C storage in mountainous regions are rare. Forest–meadow ecotones in subalpine ecosystems, which contain a mosaic of forests and meadows, may be particularly sensitive to future changes in climate and are therefore important to include in estimates of terrestrial C storage. In this study, we quantified soil C and ecosystem C pools in subalpine forest and meadow soils of the

We sought to determine whether changes in chemical composition could be a factor in increased utilization of red alder (Alnus rubra) by the two cervids, the Columbian black-tailed deer (Odocoileus hemionus columbianus) and Roosevelt elk (Cervus elaphus roosevelti), during the fall in parts of the Douglas fir region of the Pacific Northwest. We found that concentrations and astringency of...

Fire frequency affects vegetation composition and successional pathways; thus it is essential to understand fire regimes in order to manage natural resources at broad spatial scales. Fire history data are lacking for many regions for which fire management decisions are being made, so models are needed to estimate past fire frequency where local data are not yet available. We developed...

We studied Prairie Falcon (Falco mexicanus) breeding dispersal, natal dispersal, and turnover at nesting areas in the Snake River Birds of Prey National Conservation Area (NCA) from 1971- 95. Of 61 nesting areas where falcons identified one year were known to be present or absent the following year, 57% had a different falcon. This turnover rate was 2-3 times higher than that reported...

Nephroma occultum Wetm. is a rare, epiphytic lichen associated with old-growth forests of northwestern North America. We describe its distribution, abundance, and habitat within the managed landscape of a southwestern Oregon watershed. Because this species is found mainly in the canopy, we used direct canopy access (tree climbing) in combination with ground (litter) searches for our...

Roosts are a critical habitat component for bats and may influence their survival and fitness. We used radiotelemetry to investigate characteristics of day-roosts of female long-eared myotis (Myotis evotis) in watersheds characterized by different forest conditions and the spatial relationships between day-roosts and available water. We tracked 21 bats to 73 roosts (n = 102 occasions)...

We monitored activity patterns of Marbled Murrelets (Brachyramphus marmoratus) on a near-daily basis using audio-visual surveys during three breeding seasons at five forest stands in the Oregon Coast Range. Three measures of activity were recorded: number of daily detections, number of daily vocalizations, and duration of daily activity. Each measure was highly variable within and among...

No abstract available.

In laboratory tests, young Chelydra serpentina and Trachemys scripta altered their distribution in the presence of a temperature gradient. Selection of temperatures in the gradient for hatchlings and yearlings showed that body temperatures (Tbs) of C. serpentina were lower than T. scripta, but the difference was insignificant. Relatively low Tbs could allow greater activity range and...