Cheryl Brehme


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.


Highlighted Publications, Reports and Presentations by Topic

Road Ecology

Brehme CS, S Barnes, JA Tracey, BAI Ewing, C Vaughan ,and RN Fisher. 2020. Movement of Yosemite Toads Along Barrier Fencing and a Novel Elevated Road Segment in Sierra National Forest, CA. 2019. A New Road Crossing Structure for Small Animals: Case study with the Yosemite Toad. Presented at International Conference on Ecology and Transportation, Sacramento, CA Sept 22-26, 2019.

Brehme CS, JA Tracey, BAI Ewing, MJ Hobbs, A Launer, E Adelsheim, and RN Fisher. 2019. Movement of California Tiger Salamanders along barrier fencing and underpasses in Stanford, CA.  Poster presented at International Conference on Ecology and Transportation, Sacramento, CA Sept 22-26, 2019.

Brehme, C.S., Hathaway, S.A. and Fisher, R.N., 2018. An objective road risk assessment method for multiple species: ranking 166 reptiles and amphibians in California. Landscape ecology33(6), pp.911-935.

Tracey, J. A., C. S. Brehme*, Rochester, C., Clark D., and R. N. Fisher. 2015. The differential use of large underpasses by small animals and effects of adding structure. Presented at 2015 International Conference on Ecology & Transportation, Sep. 20-24, Raleigh, NC.

Tracey, J. A., C. S. Brehme, Rochester, C., Clark D., and R. N. Fisher. 2014. A Field Study of Small Vertebrate Use of Wildlife Underpasses in San Diego County, 2014. U.S. Geological DRAFT Data Summary prepared for California Department of Fish and Wildlife. 74 pp.

Brehme, C.S., Tracey, J.A., Mcclenaghan, L.R. and Fisher, R.N., 2013. Permeability of roads to movement of scrubland lizards and small mammals. Conservation Biology27(4), pp.710-720.

Brehme, C.S., 2003. Responses of Small Terrestrial Vertebrates to Roads in Coastal Sage Scrub Ecosystem. MS Thesis, San Diego State University, CA

Long-term Monitoring

Brehme, C.S., Matsuda, T.A., Adsit-Morris, D.T., Clark, D.R., Sebes, J.B., Burlaza, M.A.T. and Fisher, R.N., 2019. Track tube construction and field protocol for small mammal surveys with emphasis on the endangered Pacific pocket mouse (Perognathus longimembris pacificus) (No. 2A15). US Geological Survey.

Fisher, R.N., Brehme, C.S., Hathaway, S.A., Hovey, T.E., Warburton, M.L. and Stokes, D.C., 2018. Longevity and population age structure of the arroyo southwestern toad (Anaxyrus californicus) with drought implications. Ecology and evolution8(12), pp.6124-6132.

Mitrovich, M.J., Diffendorfer, J.E., Brehme, C.S. and Fisher, R.N., 2018. Effects of urbanization and habitat composition on site occupancy of two snake species using regional monitoring data from southern California. Global ecology and conservation15, p.e00427.

Miller, D.A., Grant, E.H.C., Muths, E., Amburgey, S.M., Adams, M.J., Joseph, M.B., Waddle, J.H., Johnson, P.T., Ryan, M.E., Schmidt, B.R. and Calhoun, D.L…..Fisher, R.N.,…..Brehme, C.S(41 authors)., 2018. Quantifying climate sensitivity and climate-driven change in North American amphibian communities. Nature communications9(1), p.3926.

Hobbs, M.T. and Brehme, C.S., 2017. An improved camera trap for amphibians, reptiles, small mammals, and large invertebrates. PloS one12(10), p.e0185026.

Matsuda T.A., Brehme, C.S. (co-primary authors), and R.N. Fisher. 2017. MCBCP Arroyo Toad Monitoring Results for 2016 with Trend Analysis from 2003-2016. U.S. Geological Survey Data Summary prepared for Marine Corps Base Camp Pendleton. 65 pp.

Brehme, C.S., D. Adsit-Morris, M. Burlaza, and R.N. Fisher. 2016. Pacific Pocket Mouse Monitoring 2015, MCB, Camp Pendleton. Prepared for AC/S Environmental Security, Marine Corps Base, Camp Pendleton. 53p.

Brehme, C.S., D.R. Clark, and Fisher, R.N. 2016. Stephens’ Kangaroo Rat Monitoring on MCB Camp Pendleton: Results and Trend Analyses for Fall-Winter 2015-16. Report prepared for AC/S Environmental Security, Marine Corps Base, Camp Pendleton. 52pp.

Iwanowicz, D.D., Vandergast, A.G., Cornman, R.S., Adams, C.R., Kohn, J.R., Fisher, R.N. and Brehme, C.S., 2016. Metabarcoding of fecal samples to determine herbivore diets: A case study of the endangered Pacific pocket mouse. PloS one, 11(11), p.e0165366.

Brehme, C.S., Clark, D.R., Rochester, C.J. and Fisher, R.N., 2011. Wildfires alter rodent community structure across four vegetation types in southern California, USA. Fire Ecology7(2), pp.81-98.

Matsuda, T., Turschak, G., Brehme, C., Rochester, C., Mitrovich, M. and Fisher, R., 2011. Effects of large-scale wildfires on ground foraging ants (Hymenoptera: Formicidae) in southern California. Environmental Entomology40(2), pp.204-216.

Rochester, C.J., Brehme, C.S., Clark, D.R., Stokes, D.C., Hathaway, S.A. and Fisher, R.N., 2010. Reptile and amphibian responses to large-scale wildfires in southern California. Journal of Herpetology44(3), pp.333-352.

Brehme, C.S., Boarman, W.I., Hathaway, S.A., Herring, A., Lyren, L., Mendelsohn, M., Pease, K., Rahn, M., Rochester, C., Stokes, D. and Turschak, G., 2009. Spatial and temporal patterns across an ecological boundary: allochthonous effects of a young saltwater lake on a desert ecosystem. Journal of arid environments73(9), pp.811-820.

Mendelsohn, M.B., Brehme, C.S., Rochester, C.J., Stokes, D.C., Hathaway, S.A. and Fisher, R.N., 2008. Responses in bird communities to wildland fires in southern California. Fire Ecology4(2), pp.63-82.

American Badger Research

Brehme, C.S., M.A. Burlaza, and R.N. Fisher. 2016. Research Results for American Badgers in Western San Diego County, 2015. Data Summary prepared for the San Diego Association of Governments. 27pp.

Brehme, C, D. Adsit-Morris, H. Smith, S. Mondol, S. Wasser, R. Fisher. 2017. The use of Canine Scent Detection, DNA testing and other methods to assess the Distribution of American Badgers in western San Diego County. Presented at 2017 International Urban Ecology Conference, June 4 to 7, San Diego, CA.

Brehme, C. Rempel R*, Smith, H, Mondol S., Wasser, S. and, R. Fisher.  2013. The Use of Canine Scent Detection and DNA Testing to Assess the Distribution of Badgers in Western San Diego County. Poster presented at the International Symposium for Badgers: Biology and Conservation. Edmonton, Alberta, Canada, Oct. 1-3, 2013