Publications
Below is a list of available NOROCK peer reviewed and published science. If you are in search of a specific publication and cannot find it below or through a search, please contact twojtowicz@usgs.gov.
Filter Total Items: 1211
Breeding site heterogeneity reduces variability in frog recruitment and population dynamics
Environmental stochasticity can have profound effects on the dynamics and viability of wild populations, and habitat heterogeneity provides one mechanism by which populations may be buffered against the negative effects of environmental fluctuations. Heterogeneity in breeding pond hydroperiod across the landscape may allow amphibian populations to persist despite variable interannual precipitation
Authors
Rebecca M. McCaffery, Lisa A. Eby, Bryce A. Maxell, Paul Stephen Corn
Body and diet composition of sympatric black and grizzly bears in the Greater Yellowstone Ecosystem
The Greater Yellowstone Ecosystem (GYE) has experienced changes in the distribution and availability of grizzly bear (Ursus arctos) food resources in recent decades. The decline of ungulates, fish, and whitebark pine seeds (Pinus albicaulis) has prompted questions regarding their ability to adapt. We examined body composition and diet of grizzly bears using bioelectrical impedance and stable isoto
Authors
Charles C. Schwartz, Jennifer K. Fortin, Justin E. Teisberg, Mark A. Haroldson, Christopher Servheen, Charles T. Robbins, Frank T. van Manen
An ecological perspective on the changing face of Brucella abortus in the western United States
After a hiatus during the 1990s, outbreaks of Brucella abortus in cattle are occurring more frequently in some of the western states of the United States, namely, Montana, Wyoming and Idaho. This increase is coincident with increasing brucellosis seroprevalence in elk (Cervus elaphus), which is correlated with elk density. Vaccines are a seductive solution, but their use in wildlife systems remain
Authors
Paul C. Cross, Eric J. Maichak, Angela Brennan, Brandon Scurlock, John C. Henningsen, Gordon Luikart
Re-introduction of tule elk to Point Reyes National Seashore, California, USA
Tule elk (Cervus elaphus nannodes), a subspecies endemic to California, was historically found in large herds throughout much of central and coastal California. Market hunting during the California Gold Rush decimated these herds, and by 1895, only two to 10 elk remained. This remnant group was protected and served as the source for early relocation efforts (McCullough, 1971). Early efforts were g
Authors
Peter J. Gogan, McCrea A. Cobb, Natalie B. Gates, Reginald H. Barrett
Spatio-temporal dynamics of pneumonia in bighorn sheep
Bighorn sheep mortality related to pneumonia is a primary factor limiting population recovery across western North America, but management has been constrained by an incomplete understanding of the disease. We analysed patterns of pneumonia-caused mortality over 14 years in 16 interconnected bighorn sheep populations to gain insights into underlying disease processes. 2. We observed four age-struc
Authors
E. Frances Cassirer, Raina K. Plowright, Kezia R. Manlove, Paul C. Cross, Andrew P. Dobson, Kathleen A. Potter, Peter J. Hudson
Vegetation of natural and artificial shorelines in Upper Klamath Basin’s fringe wetlands
The Upper Klamath Basin (UKB) in northern California and southern Oregon supports large hypereutrophic lakes surrounded by natural and artificial shorelines. Lake shorelines contain fringe wetlands that provide key ecological services to the people of this region. These wetlands also provide a context for drawing inferences about how differing wetland types and wave exposure contribute to the vege
Authors
Andrew M. Ray, Kathryn M. Irvine, Andy S. Hamilton
The effects of pulse pressure from seismic water gun technology on Northern Pike
We examined the efficacy of sound pressure pulses generated from a water gun for controlling invasive Northern Pike Esox lucius. Pulse pressures from two sizes of water guns were evaluated for their effects on individual fish placed at a predetermined random distance. Fish mortality from a 5,620.8-cm3 water gun (peak pressure source level = 252 dB referenced to 1 μP at 1 m) was assessed every 24 h
Authors
Jackson A. Gross, Kathryn M. Irvine, Siri K. Wilmoth, Tristany L. Wagner, Patrick A Shields, Jeffrey R. Fox
Genetic variation reveals influence of landscape connectivity on population dynamics and resiliency of western trout in disturbance-prone habitats
Salmonid fishes have evolved and persisted in dynamic ecosystems where disturbance events vary in frequency, magnitude, timing, and duration, as well as the specific nature of associated effects (e.g., changes in thermal or flow regimes, geomorphology, or water chemistry). In the western United States, one of the major drivers of disturbance in stream ecosystems is fire. Although there is a growin
Authors
Helen M. Neville, Robert E. Gresswell, Jason B. Dunham
The past as prelude to the future for understanding 21st-century climate effects on Rocky Mountain Trout
Bioclimatic models predict large reductions in native trout across the Rocky Mountains in the 21st century but lack details about how changes will occur. Through five case histories across the region, we explore how a changing climate has been affecting streams and the potential consequences for trout. Monitoring records show trends in temperature and hydrographs consistent with a warming climate
Authors
Daniel J. Isaak, Clint C. Muhlfeld, Andrew S. Todd, Robert Al-chokhachy, James Roberts, Jeffrey L. Kershner, Kurt D. Fausch, Steven W. Hostetler
Environmental fate model for ultra-low-volume insecticide applications used for adult mosquito management
One of the more effective ways of managing high densities of adult mosquitoes that vector human and animal pathogens is ultra-low-volume (ULV) aerosol applications of insecticides. The U.S. Environmental Protection Agency uses models that are not validated for ULV insecticide applications and exposure assumptions to perform their human and ecological risk assessments. Currently, there is no valida
Authors
Jerome J. Schleier, Robert K.D. Peterson, Kathryn M. Irvine, Lucy M. Marshall, David K. Weaver, Collin J. Preftakes
Mapped versus actual burned area within wildfire perimeters: Characterizing the unburned
For decades, wildfire studies have utilized fire occurrence as the primary data source for investigating the causes and effects of wildfire on the landscape. Fire occurrence data fall primarily into two categories: ignition points and perimeter polygons which are used to calculate a ‘burned area’ for a fire. However, understanding the relationships between climate and fire or between fire and its
Authors
Carl H Key, James Lutz, Carl H. Key, Jonathan Kane, Jan W Van Wagtendonk
A risk-based approach to evaluating wildlife demographics for management in a changing climate: A case study of the Lewis's Woodpecker
Given the projected threat that climate change poses to biodiversity, the need for proactive response efforts is clear. However, integrating uncertain climate change information into conservation planning is challenging, and more explicit guidance is needed. To this end, this article provides a specific example of how a risk-based approach can be used to incorporate a species' response to climate
Authors
Erin Towler, Victoria A. Saab, Richard S. Sojda, Katherine Dickinson, Cindy L. Bruyere, Karen R. Newlon