Publications
Below is a list of WERC's peer-reviewed publications. If you are searching for a specific publication and cannot find it in this list, please contact werc_web@usgs.gov
Filter Total Items: 3743
Cryptic genetic variation and paraphyly in ravens Cryptic genetic variation and paraphyly in ravens
Widespread species that are morphologically uniform may be likely to harbour cryptic genetic variation. Common ravens (Corvus corax) have an extensive range covering nearly the entire Northern Hemisphere, but show little discrete phenotypic variation. We obtained tissue samples from throughout much of this range and collected mitochondrial sequence and nuclear microsatellite data. Our...
Authors
K.E. Omland, C.L. Tarr, W.I. Boarman, J.M. Marzluff, R.C. Fleischer
Tidal influence on spatial dynamics of leopard sharks, Triakis semifasciata, in Tomales Bay, California Tidal influence on spatial dynamics of leopard sharks, Triakis semifasciata, in Tomales Bay, California
We used ultrasonic telemetry to determine the movement directions and movement rates of leopard sharks, Triakis semifasciata, in Tomales Bay, California. To analyze tide and time of day effects, we surgically implanted transmitters in the peritoneal cavities of one male and five female leopard sharks, which we located during summer for three to five sampling sessions lasting 12 to 24 h...
Authors
Joshua T. Ackerman, Matthew C. Kondratieff, Scott A. Matern, Joseph J. Cech
Experimental evaluation of the effect of mechanical wing decoys ('moto-duck') on hunting success and waterfowl response in California, 1999-2000 Experimental evaluation of the effect of mechanical wing decoys ('moto-duck') on hunting success and waterfowl response in California, 1999-2000
No abstract available at this time
Authors
J.M. Eadie, T.G. Moore, Joshua T. Ackerman
Root growth and function of three Mojave Desert grasses in response to elevated atmospheric CO2 concentration Root growth and function of three Mojave Desert grasses in response to elevated atmospheric CO2 concentration
Root growth and physiological responses to elevated CO2 were investigated for three important Mojave Desert grasses: the C3 perennial Achnatherum hymenoides, the C4 perennial Pleuraphis rigida and the C3 annual Bromus madritensis ssp. rubens. Seeds of each species were grown at ambient (360 μl l−1) or elevated (1000 μl l−1) CO2 in a glasshouse and harvested at three phenological stages...
Authors
C.K. Yoder, P. Vivin, L.A. DeFalco, J.R. Seemann, R.S. Nowak
Conservation of freshwater turtles Conservation of freshwater turtles
No abstract available.
Authors
V.J. Burke, J.E. Lovich, J.W. Gibbons
Using presence of sign to measure habitats used by Roosevelt elk Using presence of sign to measure habitats used by Roosevelt elk
tract Radiotelemetry and pellet-group surveys are methods used commonly to measure habi- tat use by large ungulates. However, telemetry can be expensive and analysis of data col- lected from pellet-group surveys is restricted to rank analysis. We explored the feasibil- ity of recording the presence of Roosevelt elk (Cervus elaphus roosevelti) sign to identify habitats used by elk. We...
Authors
Floyd W. Weckerly, Mark A. Ricca
Population persistence in Florida torreya: Comparing modeled projections of a declining coniferous tree Population persistence in Florida torreya: Comparing modeled projections of a declining coniferous tree
The Florida torreya ( Torreya taxifolia) is a coniferous tree endemic to a 35-km stretch of bluffs and ravines along the east side of the Apalachicola River in northern Florida and southern Georgia. This formerly locally abundant tree has declined as a result of disease during the 1950s and is on the U.S. endangered species list. With no seed production in the wild, this species is...
Authors
Mark W. Schwartz, Sharon M. Hermann, Phillip J. van Mantgem
Linking biodiversity to ecosystem function: Implications for conservation ecology Linking biodiversity to ecosystem function: Implications for conservation ecology
We evaluate the empirical and theoretical support for the hypothesis that a large proportion of native species richness is required to maximize ecosystem stability and sustain function. This assessment is important for conservation strategies because sustenance of ecosystem functions has been used as an argument for the conservation of species. If ecosystem functions are sustained at...
Authors
M.W. Schwartz, C.A. Brigham, J.D. Hoeksema, K.G. Lyons, M.H. Mills, P. van Mantgem
Distribution of Xantus' Murrelet Synthliboramphus hypoleucus at sea in the Southern California Bight, 1995-97 Distribution of Xantus' Murrelet Synthliboramphus hypoleucus at sea in the Southern California Bight, 1995-97
We radiomarked 153 Xantus' Murrelets Synthliboramphus hypoleucus captured at sea near Santa Barbara Island (SBI), the largest murrelet colony in the California Channel Islands, USA. We tracked these radiomarked murrelets in the Southern California Bight (SCB) off coastal southern California during the 1995-97 breeding seasons. In 1995 during mild El Niño conditions, the murrelets were...
Authors
Darrell L. Whitworth, John Y. Takekawa, Harry R. Carter, Scott H. Newman, Thomas W. Keeney, Paul R. Kelly
Waterfowl Distribution, Movements and Habitat Use Relative to Recent Habitat Changes in the Central Valley of California: Progress Report - June 2000 Waterfowl Distribution, Movements and Habitat Use Relative to Recent Habitat Changes in the Central Valley of California: Progress Report - June 2000
No abstract available at this time
Authors
J. P. Fleskes, J.Y. Yee, Michael L. Casazza, J. Daugherty, W.M. Perry