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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: 3724

Uncloaking a cryptic, threatened rail with molecular markers: origins, connectivity and demography of a recently-discovered population Uncloaking a cryptic, threatened rail with molecular markers: origins, connectivity and demography of a recently-discovered population

The threatened California Black Rail lives under dense marsh vegetation, is rarely observed, flies weakly and has a highly disjunct distribution. The largest population of rails is found in 8–10 large wetlands in San Francisco Bay (SF Bay), but a population was recently discovered in the foothills of the Sierra Nevada Mountains (Foothills), within a wetland network comprised of over 200...
Authors
Philippe Girard, John Y. Takekawa, Steven R. Beissinger

Scale-dependent associations of Band-tailed Pigeon counts at mineral sites Scale-dependent associations of Band-tailed Pigeon counts at mineral sites

The abundance of Band-tailed Pigeons (Patagioenas fasciata monilis) has declined substantially from historic numbers along the Pacific Coast. Identification of patterns and causative factors of this decline are hampered because habitat use data are limited, and temporal and spatial variability patterns associated with population indices are not known. Furthermore, counts are influenced...
Authors
Cory T. Overton, Michael L. Casazza, Peter S. Coates

Migration of waterfowl in the east asian flyway and spatial relationship to HPAI H5N1 outbreaks Migration of waterfowl in the east asian flyway and spatial relationship to HPAI H5N1 outbreaks

Poyang Lake is situated within the East Asian Flyway, a migratory corridor for waterfowl that also encompasses Guangdong Province, China, the epicenter of highly pathogenic avian influenza (HPAI) H5N1. The lake is the largest freshwater body in China and a significant congregation site for waterfowl; however, surrounding rice fields and poultry grazing have created an overlap with wild...
Authors
John Y. Takekawa, S. H. Newman, X. Xiao, D.J. Prosser, K.A. Spragens, E.C. Palm, B. Yan, T. Li, F. Lei, D. Zhao, David C. Douglas, S.B. Muzaffar, W. Ji

Estimating aboveground biomass for broadleaf woody plants and young conifers in Sierra Nevada, California forests Estimating aboveground biomass for broadleaf woody plants and young conifers in Sierra Nevada, California forests

Quantification of biomass is fundamental to a wide range of research and natural resource management goals. An accurate estimation of plant biomass is essential to predict potential fire behavior, calculate carbon sequestration for global climate change research, assess critical wildlife habitat, and so forth. Reliable allometric equations from simple field measurements are necessary for...
Authors
Thomas W. McGinnis, Christine D. Shook, Jon E. Keeley

Field detection of avian influenza virus in wild birds: evaluation of a portable rRT-PCR system and freeze-dried reagents Field detection of avian influenza virus in wild birds: evaluation of a portable rRT-PCR system and freeze-dried reagents

Wild birds have been implicated in the spread of highly pathogenic avian influenza (HPAIV) of the H5N1 subtype, prompting surveillance along migratory flyways. Sampling of wild birds is often conducted in remote regions, but results are often delayed because of limited local analytical capabilities, difficulties with sample transportation and permitting, or problems keeping samples cold...
Authors
John Y. Takekawa, Samuel A. Iverson, Annie K. Schultz, Nichola J. Hill, Carol J. Cardona, Walter M. Boyce, Joseph P. Dudley

Habitat suitability and conservation of the giant gartersnake (Thamnophis gigas) in the Sacramento Valley of California Habitat suitability and conservation of the giant gartersnake (Thamnophis gigas) in the Sacramento Valley of California

Resource managers often have little information regarding the habitat requirements and distribution of rare species. Factor analysis-based habitat suitability models describe the ecological niche of a species and identify locations where these conditions occur on the landscape using existing occurrence data.We used factor analyses to assess the suitability of habitats for Thamnophis...
Authors
Brian J. Halstead, Glenn D. Wylie, Michael L. Casazza

Using ecological function to develop recovery criteria for depleted species: Sea otters and kelp forests in the Aleutian archipelago Using ecological function to develop recovery criteria for depleted species: Sea otters and kelp forests in the Aleutian archipelago

Recovery criteria for depleted species or populations normally are based on demographic measures, the goal being to maintain enough individuals over a sufficiently large area to assure a socially tolerable risk of future extinction. Such demographically based recovery criteria may be insufficient to restore the functional roles of strongly interacting species. We explored the idea of...
Authors
James A. Estes, M. Tim Tinker, James L. Bodkin

Fuel buildup and potential fire behavior after stand-replacing fires, logging fire-killed trees and herbicide shrub removal in Sierra Nevada forests Fuel buildup and potential fire behavior after stand-replacing fires, logging fire-killed trees and herbicide shrub removal in Sierra Nevada forests

Typically, after large stand-replacing fires in mid-elevation Sierra Nevada forests, dense shrub fields occupy sites formerly occupied by mature conifers, until eventually conifers overtop and shade out shrubs. Attempting to reduce fuel loads and expedite forest regeneration in these areas, the USDA Forest Service often disrupts this cycle by the logging of fire-killed trees, replanting...
Authors
Thomas W. McGinnis, Jon E. Keeley, Scott L. Stephens, Gary B. Roller

Effects of subsidized predators, resource variability, and human population density on desert tortoise populations in the Mojave Desert, USA Effects of subsidized predators, resource variability, and human population density on desert tortoise populations in the Mojave Desert, USA

Understanding predator–prey relationships can be pivotal in the conservation of species. For 2 decades, desert tortoise Gopherus agassizii populations have declined, yet quantitative evidence regarding the causes of declines is scarce. In 2005, Ft. Irwin National Training Center, California, USA, implemented a translocation project including 2 yr of baseline monitoring of desert...
Authors
Todd C. Esque, Kenneth E. Nussear, K. Kristina Drake, Andrew D. Walde, Kristin H. Berry, Roy C. Averill-Murray, A. Peter Woodman, William I. Boarman, Phil A. Medica, Jeremy S. Mack, Jill S. Heaton

Factors influencing the at-sea distribution of Cassin's Auklets (Ptychoramphus aleuticus) that breed in the Channel Islands, California Factors influencing the at-sea distribution of Cassin's Auklets (Ptychoramphus aleuticus) that breed in the Channel Islands, California

We used radiotelemetry to evaluate at-sea habitat use by Cassin's Auklets (Ptychoramphus aleuticus) that bred at Prince Island, off southern California, from 1999 through 2001. We used logistic regression to compare paired radiotelemetry (presence) with random (pseudo-absence) location-associated habitat variables derived from (1) satellite remote-sensing of sea surface temperature and...
Authors
Josh Adams, John Y. Takekawa, Harry R. Carter, Julie L. Yee

Flightless and post-molt survival and movements of female mallards molting in Klamath Basin Flightless and post-molt survival and movements of female mallards molting in Klamath Basin

Flightless and post-molt survival and movements were studied during August-May, 2001-2002, 2002- 2003 and 2006-2007 for 181 adult female Mallards (Anas platyrhynchos). Birds were radiotagged just before or early in their flightless period on four wetlands that differed in size on Klamath Basin (KB) National Wildlife Refuge complex. Flightless survival varied among years but was higher on...
Authors
Joseph P. Fleskes, David M. Mauser, Julie L. Yee, David S. Blehert, Gregory S. Yarris
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