Western Ecological Research Center

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: 3,313
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Year Published: 2021

Development of demographic models to analyze populations with multi-year data—Using Agassiz’s Desert Tortoise (Gopherus agassizii) as a case study

We developed a model for analyzing multi-year demographic data for long-lived animals and used data from a population of Agassiz’s desert tortoise (Gopherus agassizii) at the Desert Tortoise Research Natural Area in the western Mojave Desert of California as a case study. The study area was 7.77 square kilometers and included two locations: inside...

Berry, Kristin H.; Yee, Julie L.
Berry, K.H., and Yee, J.L., 2021, Development of demographic models to analyze populations with multi-year data—Using Agassiz’s Desert Tortoise (Gopherus agassizii) as a case study: U.S. Geological Survey Open-File Report 2018–1094, 55 p., https://doi.org/10.3133/ofr20181094.

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Year Published: 2021

Distribution and abundance of Southwestern Willow Flycatchers (Empidonax traillii extimus) on the upper San Luis Rey River, San Diego County, California—2020 data summary

We surveyed for Southwestern Willow Flycatchers (Empidonax traillii extimus; flycatcher) along the upper San Luis Rey River, near Lake Henshaw, in Santa Ysabel, California, in 2020. Surveys were completed at four locations: three downstream from Lake Henshaw, where nest monitoring occurred from 2015 to 2019 (Rey River Ranch [RRR], Cleveland...

Howell, Scarlett L.; Kus, Barbara E.
Howell, S.L., and Kus, B.E., 2021, Distribution and abundance of Southwestern Willow Flycatchers (Empidonax traillii extimus) on the upper San Luis Rey River, San Diego County, California—2020 data summary: U.S. Geological Survey Data Series 1140, 11 p., https://doi.org/10.3133/ds1140.

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Year Published: 2021

An integrated population model for southern sea otters

Southern sea otters (Enhydra lutris nereis) have recovered slowly from their near extinction a century ago, and their continued recovery has been challenged by multiple natural and anthropogenic factors. Development of an integrated population model (IPM) for southern sea otters has been identified as a management priority, to help in evaluating...

Tinker, M. Tim; Carswell, Lilian P.; Tomoleoni, Joseph A.; Hatfield, Brian B.; Harris, Michael D.; Miller, Melissa A.; Moriarty, Megan E.; Johnson, Christine K.; Young, Colleen; Henkel, Laird A.; Staedler, Michelle M.; Miles, A. Keith; Yee, Julie L.
Tinker, M.T., Carswell, L.P., Tomoleoni, J.A., Hatfield, B.B., Harris, M.D., Miller, M.A., Moriarty, M.E., Johnson, C.K., Young, C., Henkel, L.A., Staedler, M.M., Miles, A.K., and Yee, J.L., 2021, An integrated population model for southern sea otters: U.S. Geological Survey Open-File Report 2021–1076, 50 p., https://doi.org/10.3133/ofr20211076.

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Year Published: 2021

Integrating telemetry data at several scales with spatial capture–recapture to improve density estimates

Accurate population estimates are essential for monitoring and managing wildlife populations. Mark–recapture sampling methods have regularly been used to estimate population parameters for rare and cryptic species, including the federally listed Mojave desert tortoise (Gopherus agassizii); however, the methods employed are often plagued by...

Mitchell, Corey I; Shoemaker, Kevin T.; Esque, Todd C.; Vandergast, A. G.; Hromada, Steven J.; Dutcher, Kirsten E.; Heaton, Jill S.; Nussear, Kenneth E.

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Year Published: 2021

Informing wetland management with waterfowl movement and sanctuary use responses to human-induced disturbance

Long-term environmental management to prevent waterfowl population declines is informed by ecology, movement behavior and habitat use patterns. Extrinsic factors, such as human-induced disturbance, can cause behavioral changes which may influence movement and resource needs, driving variation that affects management efficacy. To better...

McDuie, Fiona; Lorenz, Austen; Klinger, Robert C.; Overton, Cory T.; Feldheim, Cliff L.; Ackerman, Joshua T.; Casazza, Michael L.

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Year Published: 2021

Sage-grouse population dynamics are adversely impacted by overabundant feral horses

In recent decades, feral horse (Equus caballus; horse) populations increased in sagebrush (Artimesia spp.) ecosystems, especially within the Great Basin, to the point of exceeding maximum appropriate management levels (AMLmax), which were set by land administrators to balance resource use by feral horses, livestock, and wildlife....

Coates, Peter S.; O'Neil, Shawn; Munoz, Diana A.; Dwight, Ian; Tull, John C.

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Year Published: 2021

Ignitions explain more than climate or weather in driving Santa Ana Wind fires

Autumn and winter Santa Ana wind (SAW)–driven wildfires play a substantial role in area burned and societal losses in southern California. Temperature during the event and antecedent precipitation in the week or month prior play a minor role in determining area burned. Burning is dependent on wind intensity and number of human-ignited fires. Over...

Keeley, Jon; Guzman-Morales, Janin; Gershunov, Alexander; Syphard, Alexandra D.; Cayan, Daniel; Pierce, David W; Flannigan, Michael; Brown, Tim J

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Year Published: 2021

Conservation implications of spatiotemporal variation in the terrestrial ecology of Western spadefoots

Conservation of species reliant on ephemeral resources can be especially challenging in the face of a changing climate. Western spadefoots (Spea hammondii) are small burrowing anurans that breed in ephemeral pools, but adults spend the majority of their lives underground in adjacent terrestrial habitat. Western spadefoots are of conservation...

Halstead, Brian J.; Baumberger, Katherine L.; Backlin, Adam R.; Kleeman, Patrick M.; Wong, Monique Nicole; Gallegos, Elizabeth; Rose, Jonathan P.; Fisher, Robert N.

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Year Published: 2021

Climate change vulnerability assessment for the California coastal national monument—Trinidad and Point Arena-Stornetta units

Executive SummaryThe California Coastal National Monument protects islets, reefs, and rock outcropping habitats in six onshore units, including the Trinidad and Point Arena-Stornetta Units.The California Coastal National Monument provides crucial habitat for resident and migratory species of seabirds, marine mammals, and invertebrates, which...

Thorne, Karen M.; Freeman, Chase M.; Buffington, Kevin J.; De La Cruz, Susan E.W.
Thorne, K.M., Freeman, C.M., Buffington, K., and De La Cruz, S.E.W., 2021, Climate change vulnerability assessment for the California coastal national monument—Trinidad and Point Arena-Stornetta units: U.S. Geological Survey Open-File Report 2021–1050, 64 p., https://doi.org/10.3133/ofr20211050.

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Year Published: 2021

Effects of season, location, species, and sex on hematologic and plasma biochemical values and body mass in free-ranging Grebes (Aechmophorus species)

The effects of season, location, species, and sex on body weight and a comprehensive array of blood chemistry and hematology analytes were compared for free-ranging western (Aechmophorus occidentalis) and Clark's (Aechmophorus clarkii) grebes. Birds (n = 56) were collected from Puget Sound, WA, and Monterey Bay and San Francisco Bay, CA, from...

Anderson, Nancy L; De La Cruz, Susan E. W.; Gaydos, Joseph K; Ziccardi, Michael H.; Harvey, Danielle J

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Year Published: 2021

Least Bell's Vireos and Southwestern Willow Flycatchers at the San Luis Rey flood risk management project area in San Diego County, California—Breeding activities and habitat use—2020 annual report

Executive SummarySurveys and monitoring for the endangered Least Bell’s Vireo (Vireo bellii pusillus; vireo) were done at the San Luis Rey Flood Risk Management Project Area (Project Area) in the city of Oceanside, San Diego County, California, between March 31 and July 20, 2020. We completed four protocol surveys during the breeding season,...

Houston, Alexandra; Allen, Lisa D.; Pottinger, Ryan E.; Kus, Barbara E.
Houston, A., Allen, L.D., Pottinger, R.E., and Kus, B.E., 2021, Least Bell's Vireos and Southwestern Willow Flycatchers at the San Luis Rey flood risk management project area in San Diego County, California—Breeding activities and habitat use—2020 annual report: U.S. Geological Survey Open-File Report 2021–1053, 67 p., https://doi.org/10.3133/ofr20211053.

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Year Published: 2021

A tale of two valleys: Endangered species policy and the fate of the giant gartersnake

By the mid-20th Century, giant gartersnakes (Thamnophis gigas) had lost more than 90% of their Central Valley marsh habitat and were extirpated from more than two-thirds of their range. This massive habitat loss led to their inclusion in the inaugural list of rare species under the California Endangered Species Act (CESA). Listing under the CESA...

Halstead, Brian J.; Valcarcel, Patricia; Kim, Richard; Jordan, Anna; Rose, Jonathan P.; Skalos, Shannon; Reyes, Gabriel; Ersan, Julia; Casazza, Michael L.; Essert, Allison; Fulton, Alexandria M