Publications
Filter Total Items: 1990
Thermal, chemical, and optical properties of Crater Lake, Oregon
Crater Lake covers the floor of the Mount Mazama caldera that formed 7700 years ago. The lake has a surface area of 53 km2 and a maximum depth of 594 m. There is no outlet stream and surface inflow is limited to small streams and springs. Owing to its great volume and heat, the lake is not covered by snow and ice in winter unlike other lakes in the Cascade Range. The lake is isothermal in winter e
Authors
Gary L. Larson, Robert L. Hoffman, D. C. McIntire, M. W. Buktenica, Scott Girdner
Fix success and accuracy of GPS radio collars in old-growth temperate coniferous forests
Global Positioning System (GPS) telemetry is used extensively to study animal distribution and resource selection patterns but is susceptible to biases resulting from data omission and spatial inaccuracies. These data errors may cause misinterpretation of wildlife habitat selection or spatial use patterns. We used both stationary test collars and collared free-ranging American black bears (Ursus a
Authors
Kimberly A. Sager-Fradkin, Kurt J. Jenkins, Robert L. Hoffman, P. Happe, J. Beecham, R. G. Wright
Oregon Spotted Frog (Rana pretiosa) movement and demography at Dilman Meadow: Implications for future monitoring
From 2001 to 2005, we studied the demography and seasonal movement of Oregon spotted frogs (Rana pretiosa) translocated into created ponds in Dilman Meadow in central Oregon. Our objectives were to inform future monitoring and management at the site, and to elucidate poorly known aspects of the species’ population ecology. Movement rates revealed complementary use of sites seasonally, with one sma
Authors
Nathan D. Chelgren, Christopher A. Pearl, Jay Bowerman, M. J. Adams
Territoriality, prospecting, and dispersal in cooperatively breeding Micronesian Kingfishers (Todiramphus cinnamominus reichenbachii)
We investigated territoriality, prospecting, and dispersal behavior in cooperatively breeding Pohnpei Micronesian Kingfishers (Todiramphus cinnamominus reichenbachii) throughout the annual cycle using radiotelemetry and color-band resights. Mean home-range size was 6.3 ha and territories were 8.1 ha. Within territories, Micronesian Kingfishers shared 63% of their home-range space with coterritoria
Authors
D.C. Kesler, S. M. Haig
Impacts of a gape limited Brook Trout, Salvelinus fontinalis, on larval Northwestern salamander, Ambystoma gracile, growth: A field enclosure experiment
The formation of amphibian population structure is directly affected by predation. Although aquatic predators have been shown to have direct negative effects on larval salamanders in laboratory and field experiments, the potential impacts of gape-limited fish on larval salamander growth has been largely underexplored. We designed an enclosure experiment conducted in situ to quantify the effects of
Authors
C.R. Currens, W.J. Liss, R.L. Hoffman
Invasion by nonnative brook trout in Panther Creek, Idaho: Roles of local habitat quality, biotic resistance, and connectivity to source habitats
Theoretical models and empirical evidence suggest that the invasion of nonnative species in freshwaters is facilitated through the interaction of three factors: habitat quality, biotic resistance, and connectivity. We measured variables that represented each factor to determine which were associated with the occurrence of nonnative brook trout Salvelinus fontinalis in Panther Creek, a tributary to
Authors
Joseph R. Benjamin, Jason B. Dunham, M.R. Dare
Microsatellite loci for distinguishing spotted owls (Strix occidentalis), barred owls (Strix varia), and their hybrids
We identified four diagnostic microsatellite loci that distinguish spotted owls (Strix occidentalis), barred owls (Strix varia), F1 hybrids and backcrosses. Thirty-four out of 52 loci tested (65.4%) successfully amplified, and four of these loci (11.8%) had allele sizes that did not overlap between spotted and barred owls. The probability of correctly identifying a backcross with these four loci i
Authors
W. Chris Funk, Thomas D. Mullins, Eric D. Forsman, Susan M. Haig
Seasonal and interannual variability in the taxonomic composition and production dynamics of phytoplankton assemblages in Crater Lake, Oregon
Taxonomic composition and production dynamics of phytoplankton assemblages in Crater Lake, Oregon, were examined during time periods between 1984 and 2000. The objectives of the study were (1) to investigate spatial and temporal patterns in species composition, chlorophyll concentration, and primary productivity relative to seasonal patterns of water circulation; (2) to explore relationships betwe
Authors
McIntire C. David, Gary L. Larson, Robert E. Truitt
Opportunities for regional bird monitoring efforts in the Intermountain West to support the new State Wildlife Action Plans
No abstract available.
Authors
B. Altman, D. Casey, J. Bart
Marking techniques
No abstract available.
Authors
Daniel E. Varland, J.A. Smallwood, Leonard S. Young, Michael N. Kochert
Monitoring post-fire vegetation rehabilitation projects: A common approach for non-forested ecosystems
Emergency Stabilization and Rehabilitation (ES&R) and Burned Area Emergency Response (BAER) treatments are short-term, high-intensity treatments designed to mitigate the adverse effects of wildfire on public lands. The federal government expends significant resources implementing ES&R and BAER treatments after wildfires; however, recent reviews have found that existing data from monitoring and res
Authors
Troy A. Wirth, David A. Pyke
Linking the concept of scale to studies of biological diversity: evolving approaches and tools.
Although the concepts of scale and biological diversity independently have received rapidly increasing attention in the scientific literature since the 1980s, the rate at which the two concepts have been investigated jointly has grown much more slowly. We find that scale considerations have been incorporated explicitly into six broad areas of investigation related to biological diversity: (1) hete
Authors
E.A. Beever, R.K. Swihart, B. T. Bestelmeyer