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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: 3617

Sea otter population collapse in southwest Alaska: Assessing ecological covariates, consequences, and causal factors

Sea otter (Enhydra lutris) populations in southwest Alaska declined substantially between about 1990 and the most recent set of surveys in 2015. Here we report changes in the distribution and abundance of sea otters, and covarying patterns in reproduction, mortality, body size and condition, diet and foraging behavior, food availability, health profiles, and exposure to environmental contaminants

Authors
M. Tim Tinker, James L. Bodkin, Lizabeth Bowen, Brenda Ballachey, Gena Bentall, Alexander Burdin, Heather Coletti, George G. Esslinger, Brian B. Hatfield, Michael C. Kenner, Kimberly A. Kloecker, Brenda Konar, A. Keith Miles, Daniel Monson, Michael J. Murray, Ben Weitzman, James A. Estes

Changes in the abundance and distribution of waterfowl wintering in the Central Valley of California, 1973–2000

The Central Valley of California is one of the most important areas for wintering waterfowl in the world and the focus of extensive conservation efforts to mitigate for historical losses and counter continuing stressors to habitats. To guide conservation, we analyzed trends in the abundance and distribution (spatiotemporal abundance patterns) of waterfowl and their habitats in the Central Valley a
Authors
Joseph P. Fleskes, Michael L. Casazza, Cory T. Overton, Elliott Matchett, Julie L. Yee

Predictability of invasive Argentine ant distribution across Mediterranean ecoregions of southern California

The invasiveness of nonnative taxa can vary across a landscape due to environmental gradients, suggesting that location-dependent management strategies may be more effective at reducing spread compared to a “one size fits all” approach across the entire introduced range. Using bait stations placed along linear transects within habitat preserves, we tested for effects of ecoregion, vegetation, soil
Authors
Jonathan Q. Richmond, Tritia Matsuda, Cheryl S. Brehme, Emily E. Perkins, Robert N. Fisher

Wildfires and global change

No single factor produces wildfires; rather, they occur when fire thresholds (ignitions, fuels, and drought) are crossed. Anomalous weather events may lower these thresholds and thereby enhance the likelihood and spread of wildfires. Climate change increases the frequency with which some of these thresholds are crossed, extending the duration of the fire season and increasing the frequency of dry
Authors
Juli G. Pausas, Jon Keeley

Distribution and demography of coastal cactus wrens (Campylorhynchus brunneicapillus) in southern San Diego County, California—2020 data summary

Executive SummarySurveys for coastal Cactus Wren (Campylorhynchus brunneicapillus) were done in 378 established plots in southern San Diego County in 2020, encompassing three genetic clusters (Otay, Lake Jennings, and Sweetwater/Encanto genetic clusters). Two surveys were completed at each plot between March 1 and July 31. Cactus Wrens were detected in 131 plots (35 percent of plots). This is a sl
Authors
Suellen Lynn, Barbara E. Kus

Tarentola mauritanica (common wall gecko). Endoparasites

No abstract available.
Authors
Chris T. McAllister, Charles R Bursey, Samuel R Fisher, Chelsea E Martin, Robert N. Fisher

Reptile and amphibian diversity and abundance in an urban landscape: Impacts of fragmentation and the conservation value of small patches

Urbanization is a major contributor to habitat loss and fragmentation and is considered a global threat to biodiversity. We studied reptile and amphibian species diversity and abundance in a highly fragmented landscape adjacent to the second largest metropolitan area in the United States. Habitat patches in our study area were made up of remnant native vegetation surrounded by roads, housing, and
Authors
Kathleen Semple Delaney, Gary Busteed, Robert N. Fisher, Seth P D Riley

Transient disease dynamics across ecological scales

Analyses of transient dynamics are critical to understanding infectious disease transmission and persistence. Identifying and predicting transients across scales, from within-host to community-level patterns, plays an important role in combating ongoing epidemics and mitigating the risk of future outbreaks. Moreover, greater emphases on non-asymptotic processes will enable timely evaluations of wi
Authors
Yun Tao, Jessica L Hite, Kevin D. Lafferty, David J D Earn, Nita Bharti

Western pond turtles in the Mojave Desert? A review of their past, present, and possible future

=The western pond turtle (WPT) was formerly considered a single species (Actinemys or Emys marmorata) that ranged from southern British Columbia, Canada to Baja California, México. More recently it was divided into a northern and a southern species. WPTs are found primarily in streams that drain into the Pacific Ocean, although scattered populations exist in endorheic drainages of the Great Basin
Authors
Jeffrey E. Lovich, George T. Jefferson, Robert E. Reynolds, Peter A. Scott, H. Bradley Shaffer, Shellie R. Puffer, Sarah Greely, Kristy L. Cummings, Robert N. Fisher, Kathie Meyer-Wilkins, Doug Gomez, Morgan Ford, Christopher D Otahal

Assessment of disease risk associated with potential removal of anthropogenic barriers to Mojave desert tortoise (Gopherus agassizii) population connectivity

The Mojave Desert tortoise (Gopherus agassizii), federally listed as threatened, has suffered habitat loss and fragmentation due to human activities. Upper respiratory tract disease (URTD), a documented health threat to desert tortoises, has been detected at the Large-Scale Translocation Study Site (LSTS) in southwestern Nevada, US, a fenced recipient site for translocated animals. Our study aimed
Authors
Tristan L. Burgess, Josephine Braun, Carmel L Witte, Nadine Lamberski, Field. Kimberleigh J, Linda J. Allison, Roy C. Averill-Murray, K. Kristina Drake, Kenneth E. Nussear, Todd C. Esque, Bruce A Rideout

Spring phenology drives range shifts in a migratory Arctic ungulate with key implications for the future

Annual variation in phenology can have profound effects on the behavior of animals. As climate change advances spring phenology in ecosystems around the globe, it is becoming increasingly important to understand how animals respond to variation in the timing of seasonal events and how their responses may shift in the future. We investigated the influence of spring phenology on the behavior of migr
Authors
John P. Severson, Heather E. Johnson, Stephen M. Arthur, William Leacock, Michael J. Suitor

Research to inform Caltrans best management practices for reptile and amphibian road crossings

In October of 2014, the U.S. Geological Survey (USGS) began a 5-year project to conduct research to inform Best Management Practices (BMPs) for amphibian and reptile crossing and barrier systems in California. To inform future conservation and transportation planning, this project involved identification of species at highest risk of negative road impacts, creation of geodatabase and spatial mapp
Authors
Cheryl S. Brehme, Robert N. Fisher, Tom E. S. Langton, Anthony P. Clevenger, Esther Adelsheim, Stephanie Barnes, Tristan Edgarian, Brittany Ewing, Stacie A. Hathaway, Michael Hobbs, Jennifer Kingston, A. Launer, Tritia A. Matsuda, Jeremy B. Sebes, C. Vaughn, Elise Watson