Cheryl has been a biologist with the USGS, Western Ecological Research Center since 2003.
She specializes in long-term monitoring programs, conservation ecology and road ecology. She uses current ecological concepts and principles to design, implement, improve, and interpret complex research and monitoring projects for reptiles, amphibians and mammals. In addition to conducting fieldwork for her projects, she models a variety of spatial and demographic population processes and community dynamics in response to habitat change.
Long-Term monitoring
Cheryl has been integral in the design, fieldwork and dynamic occupancy analysis of data for long-term monitoring of endangered species on MCB Camp Pendleton to inform species status and trends and effective habitat and species management actions. These include the arroyo toad (since 2003), Stephens kangaroo rat (since 2005) and Pacific pocket mouse (since 2011).
Road Ecology
Cheryl leads a wide array of research on road ecology, particularly with respect to reptiles and amphibians for the Department of Transportation and other partners. Projects range from assessing risk of road impacts across multiple species, testing the effectiveness of individual components of crossing systems, designing new passages, to conducting wide scale landscape connectivity projects.
American Badger Research
Since 2011, Cheryl has led research studying badger distribution and activity in San Diego County using canine scent detection, badger sign surveys, infrared cameras, facial recognition, hair snags, outreach efforts, and road mortality to document their distribution and core use areas. Future goals include distribution mapping, designing a long-term monitoring program, and employing the use of radiotelemetry to better understand their space use patterns and conservation needs.
Science and Products
Pacific Pocket Mouse Monitoring and Research Program
Reptile and Amphibian Road Ecology
Species Observations from Pitfall Trap Arrays, Species Pool Matrices, and Patch Locations in Southern California from 1995-2015
Masticophis occupancy in southern California, 1995-2000
Interactions among rainfall, fire, forbs and non-native grasses predict occupancy dynamics for the endangered Pacific pocket mouse (Perognathus longimembris pacificus) in a Mediterranean-type ecosystem
Fecal metabarcoding of the endangered Pacific pocket mouse (Perognathus longimembris pacificus) reveals a diverse and forb rich diet that reflects local habitat availability
Elevated road segment (ERS) passage design may provide enhanced connectivity for amphibians, reptiles, and small mammals
Internal structural cover and ledges facilitate the use of large underpasses by multiple wildlife species and groups
Quantitative SWOT analysis: A structured and collaborative approach to reintroduction site selection for the endangered Pacific pocket mouse
Research to inform passage spacing for migratory amphibians and to evaluate efficacy and designs for open elevated road segment (ERS) passages
Range-wide persistence of the endangered arroyo toad (Anaxyrus californicus) for 20+ years following a prolonged drought
Impacts of a non-indigenous ecosystem engineer, the American beaver (Castor canadensis), in a biodiversity hotspot
Non-native species having high per capita impacts in invaded communities are those that modulate resource availability and alter disturbance regimes in ways that are biologically incompatible with the native biota. In areas where it has been introduced by humans, American beaver (Castor canadensis) is an iconic example of such species due to its capacity to alter trophic dynamics of entire ecosyst
Responses of migratory amphibians to barrier fencing inform the spacing of road underpasses: A case study with California tiger salamanders (Ambystoma californiense) in Stanford, CA, USA
Predictability of invasive Argentine ant distribution across Mediterranean ecoregions of southern California
Research to inform Caltrans best management practices for reptile and amphibian road crossings
The influence of species life history and distribution characteristics on species responses to habitat fragmentation in an urban landscape
Science and Products
- Science
Pacific Pocket Mouse Monitoring and Research Program
Once thought to be extinct, the Pacific pocket mouse (Perognathus longimembris pacificus) was rediscovered in 1993 and is currently found at three population sites along the southern California coast. USGS researchers and their partners developed a comprehensive long-term research and monitoring plan to assess the status and trends of Pacific pocket mouse and identify important drivers of...Reptile and Amphibian Road Ecology
USGS is working with many partners to help reptiles, amphibians and other animals cross roads safely, improving access to essential habitat. - Data
Species Observations from Pitfall Trap Arrays, Species Pool Matrices, and Patch Locations in Southern California from 1995-2015
Observations (reduced to detected/not detected) of 45 vertebrate species (seven mammals, seven amphibians, and 31 reptiles) across Southern California pitfall sampling projects conducted between 1995 through 2015. Habitat patch locations of every pitfall sampling project presented in a shapefile. Habitat patches were measured based on the size when pitfall sampling began within each. Sampling projMasticophis occupancy in southern California, 1995-2000
These data are CSV files comprised of a heading and tables from Appendix 1 and Appendix 2 in the accompanying paper. The tables show the sampling dates and locations for the coachwhip (Masticophis flagellum) and striped racer (Masticophis lateralis) in pit-fall arrays (Fisher et al. 2008) monitored in southern California from 1995-2000. GPS data are shown in decimal degrees and were collected in t - Multimedia
- Publications
Filter Total Items: 27
Interactions among rainfall, fire, forbs and non-native grasses predict occupancy dynamics for the endangered Pacific pocket mouse (Perognathus longimembris pacificus) in a Mediterranean-type ecosystem
It is important to understand species-habitat relationships to implement effective adaptive management for rare species. However, it can be challenging to assess habitat associations and their relationships to abiotic stressors in dynamic habitats without the insights that can be gained from long-term monitoring. We report results from the first six years of extensive track tube monitoring of theAuthorsCheryl S. Brehme, Sarah Kay Thomsen, Devin T. Adsit-Morris, Robert N. FisherFecal metabarcoding of the endangered Pacific pocket mouse (Perognathus longimembris pacificus) reveals a diverse and forb rich diet that reflects local habitat availability
Information on diet breadth and preference can assist in understanding links between food resources and population growth and inform habitat restoration for rare herbivores. We assessed the diet of the endangered Pacific pocket mouse using metabarcoding of fecal samples and compared it to plant community composition in long-term study plots in two populations on Marine Corps Base Camp Pendleton, SAuthorsA. G. Vandergast, Cheryl S. Brehme, Deborah D. Iwanowicz, Robert S. Cornman, Devin T. Adsit-Morris, Robert N. FisherElevated road segment (ERS) passage design may provide enhanced connectivity for amphibians, reptiles, and small mammals
Introduction: Designs for safe and effective road crossing structures for small animals are typically under-road microtunnels and culverts which have varying levels of effectiveness reported in the scientific literature. Many species, particularly migratory amphibians, may have limited ability to find and use passages if they are too far apart, resulting in substantial barrier effects.Methods: WeAuthorsCheryl S. Brehme, Stephanie Barnes, Brittany Ewing, Philip Robert Gould, Cassie Vaughan, Michael Hobbs, Charles Tornaci, Sarah Holm, Hanna Sheldon, Jon Fiutak, Robert N. FisherInternal structural cover and ledges facilitate the use of large underpasses by multiple wildlife species and groups
No abstract available.AuthorsCheryl S. Brehme, Jeff A. Tracey, Philip Robert Gould, Carlton J. Rochester, Robert N. FisherQuantitative SWOT analysis: A structured and collaborative approach to reintroduction site selection for the endangered Pacific pocket mouse
Species extinction and loss of biodiversity are major crises in the Anthropocene. Translocations of threatened and endangered species, the movement of individuals to augment existing or establish new populations, are increasingly important conservation tools, but have historically had limited success. Selection of a suitable receiver site is essential to translocation success, with poor site suitaAuthorsRachel Y. Chock, William B Miller, Shauna N D King, Cheryl S. Brehme, Robert N. Fisher, Hans Sin, Peggy Wilcox, Jill Terp, Scott Tremor, Matthew R Major, Korie Merrill, Wayne D Spencer, Sherri Sullivan, Deborah M ShierResearch to inform passage spacing for migratory amphibians and to evaluate efficacy and designs for open elevated road segment (ERS) passages
This is a multifaceted project that includes three main areas of research targeted to inform effective crossing systems for migratory amphibians, a large group of species which are at very high risk from negative impacts from roads within their habitats (Glista et al. 2008, Hamer and McDonnell 2008, Semlitsch 2008, Brehme et al. 2018). The three projects presented in this report are:1) Movement diAuthorsCheryl S. Brehme, Stephanie Barnes, Brittany Ewing, Cassie Vaughan, Michael Hobbs, Charles Tornaci, Philip Robert Gould, Sarah Holm, Hanna Sheldon, Robert N. FisherRange-wide persistence of the endangered arroyo toad (Anaxyrus californicus) for 20+ years following a prolonged drought
Prolonged drought due to climate change has negatively impacted amphibians in southern California, U.S.A. Due to the severity and length of the current drought, agencies and researchers had growing concern for the persistence of the arroyo toad (Anaxyrus californicus), an endangered endemic amphibian in this region. Range-wide surveys for this species had not been conducted for at least 20 years.AuthorsCynthia Joan Hitchcock, Elizabeth Gallegos, Adam R. Backlin, Russell Barabe, Peter H. Bloom, Kimberly Boss, Cheryl S. Brehme, Christopher W. Brown, Denise Clark, Elizabeth R. Clark, Kevin Cooper, Julie Donnell, Edward L Ervin, Peter Famolaro, Kim M. Guilliam, Jaquelyn Hancock, Nicholas Hess, Steven Howard, Valerie Hubbartt, Patrick Lieske, Robert E. Lovich, Tritia Matsuda, Katherin Meyer-Wilkins, Kamarul Muri, Barry Nerhus, Jeffrey A. Nordland, Brock Ortega, Robert Packard, Ruben Ramirez, Sam C. IV Stewart, Samuel Sweet, Manna L. Warburton, Jeffrey Wells, Ryan Winkleman, Kirsten Winter, Brian Zitt, Robert N. FisherImpacts of a non-indigenous ecosystem engineer, the American beaver (Castor canadensis), in a biodiversity hotspot
Non-native species having high per capita impacts in invaded communities are those that modulate resource availability and alter disturbance regimes in ways that are biologically incompatible with the native biota. In areas where it has been introduced by humans, American beaver (Castor canadensis) is an iconic example of such species due to its capacity to alter trophic dynamics of entire ecosyst
AuthorsJonathan Q. Richmond, Camm C. Swift, Thomas A. Wake, Cheryl S. Brehme, Kristine L. Preston, Barbara E. Kus, Edward L Ervin, Scott Tremor, Tritia Matsuda, Robert N. FisherResponses of migratory amphibians to barrier fencing inform the spacing of road underpasses: A case study with California tiger salamanders (Ambystoma californiense) in Stanford, CA, USA
Migratory amphibians are at high risk of negative impacts when roads intersect their upland and breeding habitats. Road mortality can reduce population abundance, survivorship, breeding, recruitment, and probability of long-term persistence. Increasingly, environmental planners recommend installation of under-road tunnels with barrier fencing to reduce mortality and direct amphibians towards the pAuthorsCheryl S. Brehme, Jeff A. Tracey, Brittany Ewing, Michael J. Hobbs, Alan E. Launer, Tritia Matsuda, Esther M. Cole Adelsheim, Robert N. FisherPredictability of invasive Argentine ant distribution across Mediterranean ecoregions of southern California
The invasiveness of nonnative taxa can vary across a landscape due to environmental gradients, suggesting that location-dependent management strategies may be more effective at reducing spread compared to a “one size fits all” approach across the entire introduced range. Using bait stations placed along linear transects within habitat preserves, we tested for effects of ecoregion, vegetation, soilAuthorsJonathan Q. Richmond, Tritia Matsuda, Cheryl S. Brehme, Emily E. Perkins, Robert N. FisherResearch to inform Caltrans best management practices for reptile and amphibian road crossings
In October of 2014, the U.S. Geological Survey (USGS) began a 5-year project to conduct research to inform Best Management Practices (BMPs) for amphibian and reptile crossing and barrier systems in California. To inform future conservation and transportation planning, this project involved identification of species at highest risk of negative road impacts, creation of geodatabase and spatial mappAuthorsCheryl S. Brehme, Robert N. Fisher, Tom E. S. Langton, Anthony P. Clevenger, Esther Adelsheim, Stephanie Barnes, Tristan Edgarian, Brittany Ewing, Stacie A. Hathaway, Michael Hobbs, Jennifer Kingston, A. Launer, Tritia A. Matsuda, Jeremy B. Sebes, C. Vaughn, Elise WatsonThe influence of species life history and distribution characteristics on species responses to habitat fragmentation in an urban landscape
Fragmentation within urbanized environments often leads to a loss of native species diversity; however, variation exists in responses among-species and among-populations within species.We aimed to identify patterns in species biogeography in an urbanized landscape to understand anthropogenic effects on vertebrate communities and identify species that are more sensitive or resilient to landscape chAuthorsStaci M. Amburgey, David A. W. Miller, Carlton J. Rochester, Katy S. Delaney, Seth P. D. Riley, Cheryl S. Brehme, Stacie A. Hathaway, Robert N. Fisher - News