Publications
Filter Total Items: 1994
Survival and growth of age-0 steelhead after surgical implantation of 23-mm passive integrated transponders
Little information is available on the effects of implanting 23-mm passive integrated transponder (PIT) tags in salmonids less than 90 mm fork length (FL). Using juvenile steelhead Oncorhynchus mykiss (range, 73–97 mm FL), we compared instantaneous growth rates and survival among three experimental groups: control, surgery with no tag, and surgery with tag. Survival rate was lower for tagged fish
Authors
D.S. Bateman, R. E. Gresswell
Spatial structure in the diet of imperial eagles Aquila heliaca in Kazakhstan
We evaluated the relationship between spatial variability in prey and food habits of eastern imperial eagles Aquila heliaca at a 90,000 ha national nature reserve in north-central Kazakhstan. Eagle diet varied greatly within the population and the spatial structure of eagle diet within the population varied according to the scale of measurement. Patterns in dietary response were inconsistent with
Authors
T.E. Katzner, E. A. Bragin, S.T. Knick, A.T. Smith
Factors influencing nest success of songbirds in aspen and willow riparian areas in the Great Basin
Recent studies have examined the effects of livestock grazing, agriculture, and human habitation on nest predation and brood parasitism in riparian areas in the western United States. However, we know little about factors influencing nest success in riparian areas lacking such anthropogenic influences, in part because the influences are so pervasive. We studied riparian bird communities in a 115 0
Authors
J.M. Heltzel, S.L. Earnst
Juvenile salmonid use of freshwater emergent wetlands in the floodplain and its implications for conservation management
A recent trend of enhancing freshwater emergent wetlands for waterfowl and other wildlife has raised concern about the effects of such measures on juvenile salmonids. We undertook this study to quantify the degree and extent of juvenile Pacific salmon Oncorhynchus spp. utilization of enhanced and unenhanced emergent wetlands within the floodplain of the lower Chehalis River, Washington, and to det
Authors
Julie A. Henning, Robert E. Gresswell, Ian A. Fleming
Coupled nitrogen and calcium cycles in forests of the Oregon Coast Range
Nitrogen (N) is a critical limiting nutrient that regulates plant productivity and the cycling of other essential elements in forests. We measured foliar and soil nutrients in 22 young Douglas-fir stands in the Oregon Coast Range to examine patterns of nutrient availability across a gradient of N-poor to N-rich soils. N in surface mineral soil ranged from 0.15 to 1.05% N, and was positively relate
Authors
S.S. Perakis, D.A. Maguire, T.D. Bullen, K. Cromack, R.H. Waring, J.R. Boyle
Influence of habitat heterogeneity on distribution, occupancy patterns, and productivity of breeding peregrine falcons in central West Greenland
We used occupancy and productivity data collected at 67 cliffs used for nesting from 1972 to 1999 to assess patterns of distribution and nest-site selection in an increasing population of Peregrine Falcons (Falco peregrinus) in central West Greenland. Peregrine Falcons breeding at traditionally occupied cliffs used for nesting had significantly lower variation in productivity and thus these cliffs
Authors
C.S. Wightman, M.R. Fuller
Northern goshawk diet during the nesting season in southeast Alaska
[No abstract available]
Authors
S.B. Lewis, K. Titus, M.R. Fuller
Landscape attributes and life history variability shape genetic structure of trout populations in a stream network
Spatial and temporal landscape patterns have long been recognized to influence biological processes, but these processes often operate at scales that are difficult to study by conventional means. Inferences from genetic markers can overcome some of these limitations. We used a landscape genetics approach to test hypotheses concerning landscape processes influencing the demography of Lahontan cutth
Authors
H.M. Neville, J. B. Dunham, M.M. Peacock
Fine-scale natal homing and localized movement as shaped by sex and spawning habitat in chinook salmon
Natal homing is a hallmark of the life history of salmonid fishes, but the spatial scale of homing within local, naturally reproducing salmon populations is still poorly understood. Accurate homing (paired with restricted movement) should lead to the existence of fine-scale genetic structuring due to the spatial clustering of related individuals on spawning grounds. Thus, we explored the spatial r
Authors
Helen Neville, Daniel Isaak, J. B. Dunham, Russel Thurow, B. Rieman
Observations of rapid colonization of constructed ponds by Western toad (Bufo boreas) in Oregon, USA
No abstract available.
Authors
Christopher A. Pearl, Jay Bowerman
Long-term golden eagle studies in Denali National Park and Preserve
No abstract available.
Authors
Carol L. McIntyre, Karen Steenhof, Michael N. Kochert, Michael W. Collopy
Conservation genetics in the USGS
Conservation genetics is the application of the tools and concepts of genetics to the conservation of biological resources. Once too sophisticated and expensive for routine use, the tools of conservation genetics are now widely used to address many complex management questions. These novel methods of analysis can augment assessments made with traditional methods and can bring new information to li
Authors
Ruth Jacobs, Susan Haig, Sandra L. Talbot, James Winton, Tim King, Kate Kendall