Publications
Filter Total Items: 2091
Survey trends of North American shorebirds: Population declines or shifting distributions? Survey trends of North American shorebirds: Population declines or shifting distributions?
We analyzed data from two surveys of fall migrating shorebirds in central and eastern North America to estimate annual trends in means per survey and to determine whether trends indicate a change in population size or might have been caused by other factors. The analysis showed a broad decline in means per survey in Atlantic Canada and the northeastern United States (North Atlantic...
Authors
Jonathan Bart, Stephen Brown, Brian A. Harrington, R.I. Guy Morrison
Ultraviolet radiation and bio-optics in Crater Lake, Oregon Ultraviolet radiation and bio-optics in Crater Lake, Oregon
Crater Lake, Oregon, is a mid-latitude caldera lake famous for its depth (594 m) and blue color. Recent underwater spectral measurements of solar radiation (300-800 nm) support earlier observations of unusual transparency and extend these to UV-B wavelengths. New data suggest that penetration of solar UVR into Crater Lake has a significant ecological impact. Evidence includes a...
Authors
B.R. Hargreaves, S.F. Girdner, M.W. Buktenica, R.W. Collier, E. Urbach, G.L. Larson
Arthropod prey of Wilson's Warblers in the understory of Douglas-fir forests Arthropod prey of Wilson's Warblers in the understory of Douglas-fir forests
Availability of food resources is an important factor in avian habitat selection. Food resources for terrestrial birds often are closely related to vegetation structure and composition. Identification of plant species important in supporting food resources may facilitate vegetation management to achieve objectives for providing bird habitat. We used fecal analysis to describe the diet of...
Authors
J.C. Hagar, K.M. Dugger, E. E. Starkey
Ecosystem N distribution and δ15N during a century of forest regrowth after agricultural abandonment Ecosystem N distribution and δ15N during a century of forest regrowth after agricultural abandonment
Stable isotope ratios of terrestrial ecosystem nitrogen (N) pools reflect internal processes and input–output balances. Disturbance generally increases N cycling and loss, yet few studies have examined ecosystem δ15N over a disturbance-recovery sequence. We used a chronosequence approach to examine N distribution and δ15N during forest regrowth after agricultural abandonment. Site ages...
Authors
J.E. Compton, T.D. Hooker, S.S. Perakis
Distribution of breeding shorebirds on the Arctic Coastal Plain of Alaska Distribution of breeding shorebirds on the Arctic Coastal Plain of Alaska
Available information on the distribution of breeding shorebirds across the Arctic Coastal Plain of Alaska is dated, fragmented, and limited in scope. Herein, we describe the distribution of 19 shorebird species from data gathered at 407 study plots between 1998 and 2004. This information was collected using a single-visit rapid area search technique during territory establishment and...
Authors
James A. Johnson, Richard B. Lanctot, Brad A. Andres, Jonathan Bart, Stephen C. Brown, Steven J. Kendall, David C. Payer
Impacts of a gape limited Brook Trout, Salvelinus fontinalis, on larval Northwestern salamander, Ambystoma gracile, growth: A field enclosure experiment 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...
Authors
C.R. Currens, W.J. Liss, R.L. Hoffman
Use of seasonal freshwater wetlands by fishes in a temperate river floodplain Use of seasonal freshwater wetlands by fishes in a temperate river floodplain
This study examined the use of freshwater wetland restoration and enhancement projects (i.e. non-estuarine wetlands subject to seasonal drying) by fish populations. To quantify fish use of freshwater emergent wetlands and assess the effect of wetland enhancement (i.e. addition of water control structures), two enhanced and two unenhanced emergent wetlands were compared, as well as two...
Authors
Julie A. Henning, Robert E. Gresswell, Ian A. Fleming
Occurrence of the amphibian pathogen Batrachochytrium dendrobatidis in Pacific Northwestern USA Occurrence of the amphibian pathogen Batrachochytrium dendrobatidis in Pacific Northwestern USA
Chytridiomycosis (infection by the fungus Batrachochytrium dendrobatidis) has been associated with amphibian declines in at least four continents. We report results of disease screens from 210 pond-breeding amphibians from 37 field sites in Oregon and Washington. We detected B. dendrobatidis on 28% of sampled amphibians, and and we found -> 1 detection of B. dendrobatidis from 43% of...
Authors
Christopher A. Pearl, E. L. Bull, D. E. Green, Jay Bowerman, M. J. Adams, A. Hyatt, W. Wente
Microsatellite variation reveals weak genetic structure and retention of genetic variability in threatened Chinook salmon (Oncorhynchus tshawytscha) within a Snake River watershed Microsatellite variation reveals weak genetic structure and retention of genetic variability in threatened Chinook salmon (Oncorhynchus tshawytscha) within a Snake River watershed
Pacific salmon (Oncorhynchus spp.) have been central to the development of management concepts associated with evolutionarily significant units (ESUs), yet there are still relatively few studies of genetic diversity within threatened and endangered ESUs for salmon or other species. We analyzed genetic variation at 10 microsatellite loci to evaluate spatial population structure and...
Authors
Helen Neville, Frank B. Issacs, Russel Thurow, J. B. Dunham, B. Rieman
Biotic soil crusts in relation to topography, cheatgrass, and fire in the Columbia Basin, Washington Biotic soil crusts in relation to topography, cheatgrass, and fire in the Columbia Basin, Washington
We studied lichen and bryophyte soil crust communities in a large public grazing allotment within a sagebrush steppe ecosystem in which the biotic soil crusts are largely intact. The allotment had been rested from grazing for 12 years, but experienced an extensive series of wildfires. In the 350, 4 x 0.5 m plots, stratified by topographic position, we found 60 species or species groups...
Authors
Jeanne Ponzetti, B. McCune, David A. Pyke
Dachtal Isomers and Acidic Herbicides and Pesticides in Eggs of Osprey (Pandion haliaetus) from the Seattle and Everett Areas, Washington, U.S.A Dachtal Isomers and Acidic Herbicides and Pesticides in Eggs of Osprey (Pandion haliaetus) from the Seattle and Everett Areas, Washington, U.S.A
Current-use chlorophenoxy herbicides including 2,4-dichlorophenoxyacetic acid, dicamba, triclopyr, dicamba, dimethyl tetrachloroterephthalate (DCPA or dacthal), and the metabolite of pyrethroids, 3-phenoxybenzoic acid (3-PBA), and the fungicide, chlorothalonil, were investigated in the eggs of osprey (Pandion haliaetus) that were collected from 15 sites from five study areas Puget Sound...
Authors
S. Chu, Charles J. Henny, James L. Kaiser, K.G. Drouillard, G.D. Haffner, R. J. Letcher
The state of the art in raptor electrocution research: A global review The state of the art in raptor electrocution research: A global review
We systematically reviewed the raptor electrocution literature to evaluate study designs and methods used in raptor electrocution research, mitigation, and monitoring, emphasizing original research published in English. Specifically, we wondered if three decades of effort to reduce raptor electrocutions has had positive effects. The majority of literature examined came from North America...
Authors
Robert N. Lehman, P.L. Kennedy, J. A. Savidge