Publications
Filter Total Items: 1994
Habitat selection by tundra swans on Northern Alaska breeding grounds
Habitat selection by the Tundra Swan (Cygnus columbianus columbianus) was evaluated on the Colville River Delta prior to oil field development (1982-1989). Tundra Swan territories comprised a lake, used for refuge and foraging, and terrestrial habitats and ponds near the lake's perimeter used for foraging and nesting. Tundra swan sightings from early and late summer aerial surveys were used to inv
Authors
Susan L. Earnst, T. Rothe
Spatial and temporal patterns of debris flow deposition in the Oregon Coast Range, USA
Patterns of debris-flow occurrence were investigated in 125 headwater basins in the Oregon Coast Range. Time since the previous debris-flows was established using dendrochronology, and recurrence interval estimates ranged from 98 to 357 years. Tributary basins with larger drainage areas had a greater abundance of potential landslide source areas and a greater frequency of scouring events compared
Authors
Christine L. May, Robert E. Gresswell
Populations dynamics of red brome (Bromus madritensis subsp. Rubens): Times for concern, opportunities for management
Red brome is a Mediterranean winter annual grass that has invaded south-western USA deserts. Unlike native annuals, it does not maintain a soil seed bank, but exhibits early and uniform germination. Above-average winter precipitation in these regions allows red brome to reach high density and biomass. These are time for concern, as large numbers of easily dispersed seeds increase the likelihood th
Authors
L. F. Salo
Distribution and abundance of the Mariana subspecies of the Common Moorhen
Island-wide surveys for the endangered Mariana subspecies of the Common Moorhen (Gallinula chloropus guami) were conducted on Guam and the Commonwealth of the Northern Mariana Islands from May through September 2001. Based on these counts, the total adult moorhen population is estimated to be 287, with 154, 41, 2, and 90 adult moorhens on Saipan, Tinian, Rota, and Guam, respectively. Results sugge
Authors
Leilani L. Takano, Susan M. Haig
Influence of habitat heterogeneity on the distribution of larval Pacific lamprey (Lampetra tridentata) at two spatial scales
1. Spatial patterns in channel morphology and substratum composition at small (1–10 metres) and large scales (1–10 kilometres) were analysed to determine the influence of habitat heterogeneity on the distribution and abundance of larval lamprey.2. We used a nested sampling design and multiple logistic regression to evaluate spatial heterogeneity in the abundance of larval Pacific lamprey, Lampetra
Authors
Christian E. Torgersen, David A. Close
Use of radar remote sensing (RADARSAT) to map winter wetland habitat for shorebirds in an agricultural landscape
Many of todays agricultural landscapes once held vast amounts of wetland habitat for waterbirds and other wildlife. Successful restoration of these landscapes relies on access to accurate maps of the wetlands that remain. We used C-band (5.6-cm-wavelength), HH-polarized radar remote sensing (RADARSAT) at a 38° incidence angle (8-m resolution) to map the distribution of winter shorebird (Charadriif
Authors
Oriane W. Taft, Susan M. Haig, Chris Kiilsgaard
Asymmetrical effects of introduced Rana catesbeiana on native ranid frogs in Oregon, USA
Introduced American Bullfrogs (Rana catesbeiana) have become widely established in the Pacific Northwest over the last century and are thought to be an important predator of native amphibians throughout the western United States. The Northern Red-Legged Frog (Rana aurora aurora) and Oregon Spotted Frog (Rana pretiosa) historically coexisted in portions of the Pacific Northwest now invaded by R. ca
Cervid forage utilization in noncommercially thinned ponderosa pine forests
To evaluate effects of noncommercial thinning, utilization of forages consumed by elk (Cervus elaphus L.), mule deer (Odocoileus hemionus Raf.), and white-tailed deer (Odocoileus virginianus Raf.) was measured in ponderosa pine (Pinus ponderosa P. & C. Lawson) stands in Custer State Park, S. D. Treatments consisted of unthinned (control; 22 to 32 m2/ha basal area), moderately thinned (12 to 22 m2/
Authors
M.C. Gibbs, J.A. Jenks, C.S. Deperno, B.F. Sowell, Kurt J. Jenkins
Terrestrial movements of juvenile and adult tailed frogs in relation to timber harvest in coastal British Columbia
Tailed frog (Ascaphus truei Stejneger) populations are at risk in much of the Pacific Northwest, and recolonization of sites may be slow postlogging. To examine the terrestrial movements of Ascaphus in clearcuts and old growth, we employed pitfall traps and drift-fence arrays installed along streams and 100 m into upland habitat. In the fall, we captured frogs farther from streams in old growth th
Authors
Tanya R. Wahbe, Fred L. Bunnell, R. Bruce Bury
Geographic variation in social acceptability of wildland fuels management in the western United States
Contemporary natural resource management requires consideration of the social acceptability of management practices and conditions. Agencies wishing to measure, respond to, and influence social acceptability must understand the nuances of public perception regarding controversial issues. This study explores social acceptability judgments about one such issue: reduction of wildland fuel hazards on
Status of nesting ospreys in coastal Baja California, Sonora, and Sinaloa, Mexico, 1977 and 1992-1993
No abstract available.
Authors
Charles J. Henny, Daniel W. Anderson
Science for the changing Great Basin
The U.S. Geological Survey (USGS), with its multidisciplinary structure and role as a federal science organization, is well suited to provide integrated science in the Great Basin of the western United States. A research strategy developed by the USGS and collaborating partners addresses critical management issues in the basin, including invasive species, status and trends of wildlife populations
Authors
Erik Beever, David A. Pyke