Skip to main content
U.S. flag

An official website of the United States government

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

Inferring social structure and its drivers from refuge use in the desert tortoise, a relatively solitary species

For several species, refuges (such as burrows, dens, roosts, nests) are an essential resource for protection from predators and extreme environmental conditions. Refuges also serve as focal sites for social interactions, including mating, courtship, and aggression. Knowledge of refuge use patterns can therefore provide information about social structure, mating, and foraging success, as well as th
Authors
Pratha Sah, Kenneth E. Nussear, Todd C. Esque, Christina M. Aiello, Peter J. Hudson, Shweta Bansal

Spatial and temporal patterns of mercury concentrations in freshwater fish across the Western United States and Canada

Methylmercury contamination of fish is a global threat to environmental health. Mercury (Hg) monitoring programs are valuable for generating data that can be compiled for spatially broad syntheses to identify emergent ecosystem properties that influence fish Hg bioaccumulation. Fish total Hg (THg) concentrations were evaluated across the Western United States (US) and Canada, a region defined by e
Authors
Collin A. Eagles-Smith, Joshua T. Ackerman, James J. Willacker, Michael T. Tate, Michelle A. Lutz, Jacob Fleck, A. Robin Stewart, James G. Wiener, David C. Evers, Jesse M. Lepak, Jay A. Davis, Colleen Flanagan Pritz

Longitudinal evaluation of leukocyte transcripts in killer whales (Orcinus Orca)

Early identification of illness and/or presence of environmental and/or social stressors in free-ranging and domestic cetaceans is a priority for marine mammal health care professionals. Incorporation of leukocyte gene transcript analysis into the diagnostic tool kit has the potential to augment classical diagnostics based upon ease of sample storage and shipment, inducible nature and well-defined
Authors
Tatjana Sitt, Lizabeth Bowen, Chia-Shan Lee, Myra Blanchard, James McBain, Christopher Dold, Jeffrey L. Stott

Biotelemetry data for golden eagles (Aquila chrysaetos) captured in coastal southern California, November 2014–February 2016

The status of golden eagles (Aquila chrysaetos) in coastal southern California is unclear. To address this knowledge gap, the U.S. Geological Survey (USGS) in collaboration with local, State, and other Federal agencies began a multi-year survey and tracking program of golden eagles to address questions regarding habitat use, movement behavior, nest occupancy, genetic population structure, and huma
Authors
Jeff A. Tracey, Melanie C. Madden, Jeremy B. Sebes, Peter H. Bloom, Todd E. Katzner, Robert N. Fisher

Does prescribed fire promote resistance to drought in low elevation forests of the Sierra Nevada, California, USA?

Prescribed fire is a primary tool used to restore western forests following more than a century of fire exclusion, reducing fire hazard by removing dead and live fuels (small trees and shrubs).  It is commonly assumed that the reduced forest density following prescribed fire also reduces competition for resources among the remaining trees, so that the remaining trees are more resistant (more likel
Authors
Phillip J. van Mantgem, Anthony C. Caprio, Nathan L. Stephenson, Adrian J. Das

Potential effects of sea-level rise on plant productivity: Species-specific responses in northeast Pacific tidal marshes

Coastal wetland plants are adapted to varying degrees of inundation. However, functional relationships between inundation and productivity are poorly characterized for most species. Determining species-specific tolerances to inundation is necessary to evaluate sea-level rise (SLR) effects on future marsh plant community composition, quantify organic matter inputs to marsh accretion, and inform pre
Authors
Christopher Janousek, Kevin J. Buffington, Karen M. Thorne, Glenn R. Guntenspergen, John Y. Takekawa, Bruce D. Dugger

Biogeographical history and coalescent species delimitation of Pacific island skinks (Squamata: Scincidae: Emoia cyanura species group)

Aim A prevailing hypothesis for how Pacific islands organisms have obtained their extant distributions is that of a stepping-stone model, in which populations originate from Papua New Guinea in the western Pacific and gradually disperse eastward. Here, we test this model using a spatiotemporal framework for Emoia cyanura and E. impar, two species within the Emoia cyanura species group (ECSG; Famil
Authors
Elaine Klein, Rebecca Harris, Robert N. Fisher, Tod Reeder

Multi-scale connectivity and graph theory highlight critical areas for conservation under climate change

Conservation planning and biodiversity management require information on landscape connectivity across a range of spatial scales from individual home ranges to large regions. Reduction in landscape connectivity due changes in land-use or development is expected to act synergistically with alterations to habitat mosaic configuration arising from climate change. We illustrate a multi-scale connectiv
Authors
Thomas E. Dilts, Peter J. Weisberg, Phillip Leitner, Marjorie D. Matocq, Richard D. Inman, Ken E. Nussear, Todd C. Esque

Avian mercury exposure and toxicological risk across western North America: A synthesis

Methylmercury contamination of the environment is an important issue globally, and birds are useful bioindicators for mercury monitoring programs. The available data on mercury contamination of birds in western North America were synthesized. Original data from multiple databases were obtained and a literature review was conducted to obtain additional mercury concentrations. In total, 29219 origi
Authors
Joshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog, C. Alex Hartman, Sarah H. Peterson, David C. Evers, Allyson K. Jackson, John E. Elliott, Stacy S. Vander Pol, Colleen E. Bryan

Host contact and shedding patterns clarify variation in pathogen exposure and transmission in threatened tortoise Gopherus agassizii: implications for disease modelling and management

Summary Most directly transmitted infections require some form of close contact between infectious and susceptible hosts to spread. Often disease models assume contacts are equal and use mean field estimates of transmission probability for all interactions with infectious hosts. Such methods may inaccurately describe transmission when interactions differ substantially in their ability to cause in
Authors
Christina M. Aiello, Kenneth E. Nussear, Todd C. Esque, Patrick G. Emblidge, Pratha Sah, Shweta Bansal, Peter J. Hudson

Differentiating sex and species of Western Grebes (Aechmophorus occidentalis) and Clark's Grebes (Aechmophorus clarkii) and their eggs using external morphometrics and discriminant function analysis

In birds where males and females are similar in size and plumage, sex determination by alternative means is necessary. Discriminant function analysis based on external morphometrics was used to distinguish males from females in two closely related species: Western Grebe (Aechmophorus occidentalis) and Clark's Grebe (A. clarkii). Additionally, discriminant function analysis was used to evaluate mor
Authors
C. Alex Hartman, Joshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog

The high cost of motherhood: End-lactation syndrome in southern sea otters (Enhydra lutris nereis) on the central California, USA, coast

Sea otters (Enhydra lutris) have exceptionally high energetic requirements, which nearly double during lactation and pup care. Thus, females are extremely vulnerable to caloric insufficiency. Despite a number of compensatory strategies, the metabolic challenge of reproduction culminates in numerous maternal deaths annually. Massive depletion of energy reserves results in a case presentation that w
Authors
Sarah S Chinn, Melissa A. Miller, M. Tim Tinker, Michelle M. Staedler, Francesca I. Batac, Erin M. Dodd, Laird A. Henkel