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
Vegetation changes associated with a population irruption by Roosevelt elk
Interactions between large herbivores and their food supply are central to the study of population dynamics. We assessed temporal and spatial patterns in meadow plant biomass over a 23-year period for meadow complexes that were spatially linked to three distinct populations of Roosevelt elk (Cervus elaphus roosevelti) in northwestern California. Our objectives were to determine whether the plant c
Authors
H D Starns, Floyd W. Weckerly, Mark A. Ricca, Adam Duarte
Export of fine particulate organic carbon from redwood-dominated catchments
Recently, researchers have recognized the significant role of small mountainous river systems in the transport of carbon from terrestrial environments to the ocean, and the scale of such studies have ranged from channel bed units to continents. In temperate zones, these mountain river systems commonly drain catchments that are largely forested. However, the magnitude of carbon export from rivers d
Authors
Mary Ann Madej
Impacts of fire management on aboveground tree carbon stocks in Yosemite and Sequoia & Kings Canyon National Parks
Forest biomass on Sierra Nevada landscapes constitutes one of the largest carbon stocks in California, and its stability is tightly linked to the factors driving fire regimes. Research suggests that fire suppression, logging, climate change, and present management practices in Sierra Nevada forests have altered historic patterns of landscape carbon storage, and over a century of fire suppression a
Authors
John R. Matchett, James A. Lutz, Leland W. Tarnay, Douglas G. Smith, Kendall M.L. Becker, Matthew L. Brooks
Making the transition to the third era of natural resources management
We are entering the third era of National Park Service (NPS) natural resources management— an era defined by rapid and unprecedented global changes. This third era promises to overturn not only some of our most fundamental assumptions about parks and protected areas, but also many of the ideals we currently hold dear. A common initial reaction to the diverse challenges of this transition is to fee
Authors
Nathan L. Stephenson
The precarious persistence of the endangered Sierra Madre yellow-legged frog Rana muscosa in southern California, USA
We conducted surveys for the Endangered Sierra Madre yellow-legged frog Rana muscosa throughout southern California to evaluate the current distribution and status of the species. Surveys were conducted during 2000–2009 at 150 unique streams and lakes within the San Gabriel, San Bernardino, San Jacinto, and Palomar mountains of southern California. Only nine small, geographically isolated populati
Authors
Adam R. Backlin, Cynthia J. Hitchcock, Elizabeth A. Gallegos, Julie L. Yee, Robert N. Fisher
The critical role of islands for waterbird breeding and foraging habitat in managed ponds of the South Bay Salt Pond Restoration Project, South San Francisco Bay, California
The South Bay Salt Pond Restoration Project aims to restore 50–90 percent of former salt evaporation ponds into tidal marsh in South San Francisco Bay, California. However, large numbers of waterbirds use these ponds annually as nesting and foraging habitat. Islands within ponds are particularly important habitat for nesting, foraging, and roosting waterbirds. To maintain current waterbird populat
Authors
Joshua T. Ackerman, C. Alex Hartman, Mark P. Herzog, Lacy M. Smith, Stacy M. Moskal, Susan E.W. De La Cruz, Julie L. Yee, John Y. Takekawa
Mercury in birds of San Francisco Bay-Delta, California: trophic pathways, bioaccumulation, and ecotoxicological risk to avian reproduction
San Francisco Bay Estuary in northern California has a legacy of mercury contamination, which could reduce the health and reproductive success of waterbirds in the estuary. The goal of this study was to use an integrated field and laboratory approach to evaluate the risks of mercury exposure to birds in the estuary. We examined mercury bioaccumulation, and other contaminants of concern, in five wa
Authors
Joshua T. Ackerman, Collin A. Eagles-Smith, Gary Heinz, Susan E.W. De La Cruz, John Y. Takekawa, A. Keith Miles, Terrence L. Adelsbach, Mark P. Herzog, Jill D. Bluso-Demers, Scott A. Demers, Garth Herring, David J. Hoffman, Christopher A. Hartman, James J. Willacker, Thomas H. Suchanek, Steven E. Schwarzbach, Thomas C. Maurer
Distance to human populations influences epidemiology of respiratory disease in desert tortoises
We explored variables likely to affect health of Agassiz's desert tortoises (Gopherus agassizii) in a 1,183-km2 study area in the central Mojave Desert of California between 2005 and 2008. We evaluated 1,004 tortoises for prevalence and spatial distribution of 2 pathogens, Mycoplasma agassizii and M. testudineum, that cause upper respiratory tract disease. We defined tortoises as test-positive if
Authors
Kristin H. Berry, no longer USGS Ashley A. Coble (formerly Emerson), Julie L. Yee, Jeremy S. Mack, William M. Perry, Kemp M. Anderson, Mary B. Brown
Densovirus associated with sea-star wasting disease and mass mortality
Populations of at least 20 asteroid species on the Northeast Pacific Coast have recently experienced an extensive outbreak of sea-star (asteroid) wasting disease (SSWD). The disease leads to behavioral changes, lesions, loss of turgor, limb autotomy, and death characterized by rapid degradation (“melting”). Here, we present evidence from experimental challenge studies and field observations that l
Authors
Ian Hewson, Jason B. Button, Brent M. Gudenkauf, Benjamin Miner, Alisa L. Newton, Joseph K. Gaydos, Janna Wynne, Cathy L. Groves, Gordon Hendler, Michael Murray, Steven Fradkin, Mya Breitbart, Elizabeth Fahsbender, Kevin D. Lafferty, A. Marm Kilpatrick, C. Melissa Miner, Peter T. Raimondi, Lesanna L. Lahner, Carolyn S. Friedman, Stephen D. Danielson, Martin Haulena, Jeffrey Marliave, Colleen A. Burge, Morgan E. Eisenlord, C. Drew Harvell
Disease dynamics during wildlife translocations: disruptions to the host population and potential consequences for transmission in desert tortoise contact networks
Wildlife managers consider animal translocation a means of increasing the viability of a local population. However, augmentation may disrupt existing resident disease dynamics and initiate an outbreak that would effectively offset any advantages the translocation may have achieved. This paper examines fundamental concepts of disease ecology and identifies the conditions that will increase the like
Authors
Christina M. Aiello, Kenneth E. Nussear, Andrew D. Walde, Todd C. Esque, Patrick G. Emblidge, Pratha Sah, S. Bansal, Peter J. Hudson
Prey choice and habitat use drive sea otter pathogen exposure in a resource-limited coastal system
The processes promoting disease in wild animal populations are highly complex, yet identifying these processes is critically important for conservation when disease is limiting a population. By combining field studies with epidemiologic tools, we evaluated the relationship between key factors impeding southern sea otter (Enhydra lutris nereis) population growth: disease and resource limitation. Th
Authors
Christine K. Johnson, M. Tim Tinker, James A. Estes, Patricia A. Conrad, Michelle M. Staedler, Melissa A. Miller, David A. Jessup, Jonna A.K. Mazet
Photographic evidence of interspecies mating in geckos of the Lepidodactylus lugubris unisexual-bisexual complex (Squamata: Gekkonidae)
An interspecies mating between unisexual Lepidodactylus lugubris and a male of the bisexual Lepidodactylus moestus was photographed by Carlos Cianchini on Kosrae [Island], FSM, at 18:15 h on 22 August 2013 (Figure 1). The mating pair was on a window frame inside a house at Pukusruk Wan village (05°21'01" N, 163°00'41" E, elev. 28 m a.s.l.) on the northeastern side of the island. This is the first
Authors
Donald W. Buden, Carlos Cianchini, Danko Taborosi, Robert N. Fisher, Aaron Bauer, Ivan Ineich