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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

Increased body mass of ducks wintering in California's Central Valley

Waterfowl managers lack the information needed to fully evaluate the biological effects of their habitat conservation programs. We studied body condition of dabbling ducks shot by hunters at public hunting areas throughout the Central Valley of California during 2006–2008 compared with condition of ducks from 1979 to 1993. These time periods coincide with habitat increases due to Central Valley Jo
Authors
Joseph P. Fleskes, Julie L. Yee, Gregory S. Yarris, Daniel L. Loughman

Habitat selection by juvenile Mojave Desert tortoises

Growing pressure to develop public lands for renewable energy production places several protected species at increased risk of habitat loss. One example is the Mojave desert tortoise (Gopherus agassizii), a species often at the center of conflicts over public land development. For this species and others on public lands, a better understanding of their habitat needs can help minimize negative impa
Authors
Brian D Todd, Brian J. Halstead, Lindsay P. Chiquoine, J. Mark Peaden, Kurt A. Buhlmann, Tracey D. Tuberville, Aleta Nafus

It’s what’s inside that counts: Egg contaminant concentrations are influenced by estimates of egg density, egg volume, and fresh egg mass

In egg contaminant studies, it is necessary to calculate egg contaminant concentrations on a fresh wet weight basis and this requires accurate estimates of egg density and egg volume. We show that the inclusion or exclusion of the eggshell can influence egg contaminant concentrations, and we provide estimates of egg density (both with and without the eggshell) and egg-shape coefficients (used to e
Authors
Mark P. Herzog, Joshua T. Ackerman, Collin A. Eagles-Smith, C. Alex Hartman

Desert tortoise annotated bibliography, 1991-2015

Introduction Agassiz’s desert tortoise, Gopherus agassizii, was considered a single species for 150 years after its discovery by James Cooper (1861), with a geographic range extending from southeastern California, southern Nevada, and southwestern Utah southward into northern Sinaloa, Mexico (Murphy and others, 2011). What was once G. agassizii is now recognized as a complex composed of three sist
Authors
Kristin H. Berry, Lisa M. Lyren, Jeremy S. Mack, L. Arriana Brand, Dustin A. Wood

Predictive mapping of seabirds, pinnipeds and cetaceans off the Pacific Coast of Washington

About this report This report supports Washington-led marine spatial planning and responsible stewardship of natural and cultural resources by the Olympic Coast National Marine Sanctuary. Washington state agencies and the sanctuary continually seek the best available science to improve management of marine uses and stewardship of resources (Etheridge et al., 2010; Washington Department of Fish and
Authors
Charles Menza, Jeffery B. Leirness, Tim White, Arliss Winship, Brian P. Kinlan, Laura Kracker, Jeannette E. Zamon, Lisa Ballance, Elizabeth Becker, Karin A. Forney, Jay Barlow, Josh Adams, David Pereksta, Scott Pearson, John Pierce, Steven J. Jeffries, John Calambokidis, Annie Douglas, Bradford C. Hanson, Scott R. Benson, Liam Antrim

Maternal transfer of contaminants in birds: Mercury and selenium concentrations in parents and their eggs

We conducted a detailed assessment of the maternal transfer of mercury and selenium to eggs in three bird species (n = 107 parents and n = 339 eggs), and developed predictive equations linking contaminant concentrations in eggs to those in six tissues of the mother (blood, muscle, liver, kidney, breast feathers, and head feathers). Mercury concentrations in eggs were positively correlated with mer
Authors
Joshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog, C. Alex Hartman

Marine disease impacts, diagnosis, forecasting, management and policy

As Australians were spending millions of dollars in 2014 to remove the coral-eating crown of thorns sea star from the Great Barrier Reef, sea stars started washing up dead for free along North America's Pacific Coast. Because North American sea stars are important and iconic predators in marine communities, locals and marine scientists alike were alarmed by what proved to be the world's most wides
Authors
Kevin D. Lafferty, Eileen E. Hofmann

Fishing diseased abalone to promote yield and conservation

Past theoretical models suggest fishing disease-impacted stocks can reduce parasite transmission, but this is a good management strategy only when the exploitation required to reduce transmission does not overfish the stock. We applied this concept to a red abalone fishery so impacted by an infectious disease (withering syndrome) that stock densities plummeted and managers closed the fishery. In a
Authors
Tal Ben-Horin, Kevin D. Lafferty, Gorka Bidegain, Hunter S. Lenihan

Mercury correlations among blood, muscle, and hair of northern elephant seals during the breeding and molting fasts

Mercury (Hg) biomonitoring and toxicological risk assessments for marine mammals commonly sample different tissues, making comparisons to toxicity benchmarks and among species and regions difficult. Few studies have examined how life history events, such as fasting, influence the relationship between total Hg (THg) concentrations in different tissues. We evaluated the relationships between THg con
Authors
Sarah H. Peterson, Joshua T. Ackerman, Daniel P. Costa

Chaparral

One of the most dynamic California ecosystems is chaparral. Dominated by evergreen, sclerophyllous shrubs and small trees, chaparral is the most extensive vegetation type in the state (Figure 1). The nearly impenetrable tangle of stiff branches of this unusual vegetation inhibits exploration, and as a consequence the public know little about its natural history and unique characteristics. This und
Authors
V. Thomas Parker, R. Brandon Pratt, Jon E. Keeley

Conservation issues: California chaparral

California chaparral, a sclerophyllous shrub-dominated plant community shaped by a Mediterranean-type climate and infrequent, high-intensity fire, is one of the most biodiverse and threatened habitats on Earth. Distinct forms of chaparral, distinguished by differing species composition, geography, and edaphic characteristics, can cover thousands of hectares with dense vegetation or be restricted t
Authors
Richard W. Halsey, Jon E. Keeley

Endangered species management and ecosystem restoration: Finding the common ground

Management actions to protect endangered species and conserve ecosystem function may not always be in precise alignment. Efforts to recover the California Ridgway’s Rail (Rallus obsoletus obsoletus; hereafter, California rail), a federally and state-listed species, and restoration of tidal marsh ecosystems in the San Francisco Bay estuary provide a prime example of habitat restoration that has con
Authors
Michael L. Casazza, Cory T. Overton, Thuy-Vy D. Bui, Joshua M. Hull, Joy D. Albertson, Valary K. Bloom, Steven Bobzien, Jennifer McBroom, Marilyn Latta, Peggy Olofson, Tobias M. Rohmer, Steven E. Schwarzbach, Donald R. Strong, Erik Grijalva, Julian K. Wood, Shannon Skalos, John Y. Takekawa