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

Occurrence of a suite of stream-obligate amphibians in timberlands of Mendocino County, California, examined using environmental DNA

Stream-obligate amphibians are important indicators of ecosystem health in the Pacific Northwest, but distributional information to improve forest management is lacking in many regions. We analyzed archived DNA extracted from water samples in 60 pools in streams on private timberlands in Mendocino County, California, for 3 California Species of Special Concern—Coastal Tailed Frogs (Ascaphus truei)
Authors
Brian J. Halstead, Caren S. Goldberg, Robert B Douglas, Patrick M. Kleeman, David W Ulrich

Dispersal of hatchling Ouachita map turtles (Graptemys ouachitensis) from natural nests on the lower Wisconsin River, Wisconsin, USA

Despite its importance to individual fitness and population dynamics, the dispersal behaviors of most neonate freshwater turtles after nest emergence are poorly known. We studied the initial dispersal tendencies of neonate Ouachita map turtles (Graptemys ouachitensis) exiting natural nests during 2015–2017 along the Wisconsin River, Wisconsin. Overall, dispersal was nonrandom, and hatchlings large
Authors
Gregory A Geller, Gary S Casper, Brian J. Halstead

Effects of postfire climate and seed availability on postfire conifer regeneration

Large, severe fires are becoming more frequent in many forest types across the western United States and have resulted in tree mortality across tens of thousands of hectares. Conifer regeneration in these areas is limited because seeds must travel long distances to reach the interior of large burned patches and establishment is jeopardized by increasingly hot and dry conditions. To better inform p
Authors
Joseph A E Stewart, Phillip J. van Mantgem, Derek J N Young, Kristen L. Shive, Haiganoush K. Preisler, Adrian Das, Nathan L. Stephenson, Jon Keeley, Hugh D. Safford, Micah C. Wright, Kevin R Welch, James H. Thorne

Behavioral responses across a mosaic of ecosystem states restructure a sea otter–urchin trophic cascade

Consumer and predator foraging behavior can impart profound trait-mediated constraints on community regulation that scale up to influence the structure and stability of ecosystems. Here, we demonstrate how the behavioral response of an apex predator to changes in prey behavior and condition can dramatically alter the role and relative contribution of top-down forcing, depending on the spatial orga
Authors
Joshua G Smith, Joseph A. Tomoleoni, Michelle M. Staedler, Sophia Lyon, Jessica Fujii, M. Tim Tinker

Feral burros and other influences on desert tortoise presence in the western Sonoran Desert

Across the globe, conflicting priorities exist in how land and resources are managed. In the American West, conflicts are common on public lands with historical mandates for multiple uses. We explored the impacts of multiple uses of land in a case study of Agassiz's Desert Tortoises (Gopherus agassizii), a federally threatened species, in the western Sonoran Desert. The tortoise has declined for m
Authors
Kristin H. Berry, Julie L. Yee, Lisa L. Lyren

Examining the potential conflict between sea otter recovery and Dungeness crab fisheries in California

Human exploitation of marine mammals led to precipitous declines in many wild populations within the last three centuries. Legal protections enacted throughout the 20th century have enabled the recovery of many of these species and some recoveries have resulted in conflict with humans for shared resources. With legal protections and reintroduction programs, the southern sea otter (Enhydra lutris n
Authors
Andre M. Boustany, David Hernandez, Emily A Miller, Fujii. Jessica, Teri E. Nicholson, Joseph A. Tomoleoni, Kyle S. Van Houtan

Population estimates for selected breeding seabirds at Kīlauea Point National Wildlife Refuge, Kauaʻi, in 2019

Kīlauea Point National Wildlife Refuge (KPNWR) is an important seabird breeding site located at the northeastern tip of Kauaʻi in the main Hawaiian Islands. Despite the regional significance of KPNWR as one of the most important breeding sites for red-tailed tropicbirds (Phaethon rubricauda), red-footed boobies (Sula sula), and wedge-tailed shearwaters (Ardenna pacifica) in the main Hawaiian Islan
Authors
Jonathan J. Felis, Emily C. Kelsey, Josh Adams, Jennilyn G. Stenske, Laney M. White

Influence of niche breadth and position on the historical biogeography of seafaring scincid lizards

Niche breadth and position can influence diversification among closely related species or populations, yet limited empirical data exist concerning the predictability of the outcomes. We explored the effects of these factors on the evolution of the Emoia atrocostata species group, an insular radiation of lizards in the western Pacific Ocean and Indo-Australasia composed of both endemic and widespre
Authors
Jonathan Q. Richmond, Hidetoshi Ota, L Lee Grismer, Robert N. Fisher

Conservation genomics of the threatened western spadefoot, Spea hammondii, in urbanized southern California

Populations of the western spadefoot (Spea hammondii) in southern California occur in one of the most urbanized and fragmented landscapes on the planet and have lost up to 80% of their native habitat. Orange County is one of the last strongholds for this pond-breeding amphibian in the region, and ongoing restoration efforts targeting S. hammondii have involved habitat protection and the constructi
Authors
Kevin M Neal, Robert N. Fisher, Milan J. Mitrovich, H. Bradley Shaffer

Time-to-detection occupancy methods: Performance and utility for improving efficiency of surveys

Occupancy methods propelled the quantitative study of species distributions forward by separating the observation process, or the imperfect detectability of species, from the ecological processes of interest governing species distributions. Occupancy studies come at a cost, however: the collection of additional data to account for nondetections at sites where the species is present. The most commo
Authors
Brian J. Halstead, Jonathan P. Rose, Patrick M. Kleeman

Whitebark pine in the national parks of the Pacific states: An assessment of population vulnerability

Whitebark pine (Pinus albicaulis) is a long-lived tree found in high-elevation forests of western North America that is declining due to the non-native white pine blister rust (Cronartium ribicola) and climate-driven outbreaks of mountain pine beetle (Dendroctonus ponderosae; MPB). The National Park Service established a monitoring program for whitebark pine in seven parks, including Sequoia & Kin
Authors
Erik S Jules, Phillip J. van Mantgem, Benjamin G Iberle, Jonathan C B Nesmith, Regina M Rochefort