Dr. Robert Fisher is a conservation biologist with the U.S. Geological Survey’s Western Ecological Research Center and works as part of a large integrated team.
His focus has been on how natural systems are responding to the Anthropocene, and what types of resiliency they have or lack as it relates to maintaining ecological integrity and biodiversity. Additionally, through understanding individual species and community responses to perturbations through modern monitoring techniques, he and his team can determine appropriate management experiments or options to possibly recover resiliency. Geographically they have two foci, the first is southern California where urbanization and conservation planning bring various direct and indirect drivers of ecological change, and climate variability is currently extreme and drives landscape level drought and wildfires. Their second foci are the tropical islands of the Pacific Basin, from Palau and Papua New Guinea east to Hawai’i. These islands have also been driven by human change and are on the front line as extreme recent weather variability in the cyclone belt impact terrestrial ecosystems. Understanding how biodiversity was generated in this ecoregion is critical to managing its loss, and their team focuses across time and space (biogeography) to understand these processes utilizing molecular tools tied to expeditions of discovery in this poorly studied ecoregion.
RESEARCH INTERESTS
- Conservation biology
- Biogeography
- Modelling
- Natural history
- Speciation
- Invasive species
- Climate variability
- Anthropocene
Education and Certifications
Ph.D., Population Biology, University of California, Davis, CA 1995
M.S., Zoology, University of California, Davis, CA 1991
B.S., Biology, University of California, Irvine, CA 1988
Science and Products
Tracking Bats and Coronaviruses
Pacific Pocket Mouse Monitoring and Research Program
Reptile and Amphibian Road Ecology
WERC Fire Science
Amphibian Research in Southern California
Golden Eagles in Coastal Southern California
Reptile Biodiversity in the Pacific Basin Islands
San Diego Field Station
Elucidating mechanisms underlying amphibian declines in North America using hierarchical spatial models
Mercury concentrations in amphibian tissues across the United States, 2016-2021
Raster data files for Prioritizing conserved areas threatened by wildfire for monitoring and management.
Western Spadefoot Survey Data in Northern and Central California (2019)
Long-distance movements of non-migratory golden eagles in western North America, 2007-2017
Detection/non-detection data on territorial pairs of golden eagles in coastal southern California, 2016-2017
Western Spadefoot Habitat Selection Based on Radio Telemetry in Orange County, California 2019
Species Observations from Pitfall Trap Arrays, Species Pool Matrices, and Patch Locations in Southern California from 1995-2015
Amphibian capture mark-recapture
Masticophis occupancy in southern California, 1995-2000
Predictor, null model, response variable, and habitat suitability prediction rasters for a golden eagle hierarchical Bayesian synoptic model used for habitat selection in San Diego County, California. Derived from golden eagle data collected from November
Microsatellite genotype scores for a contemporary, range-wide sample of Santa Ana sucker in southern California
New record of California red-legged frogs (Rana draytonii) in Whitewater Canyon, Riverside County, CA, USA
Native amphibian toxin reduces invasive crayfish feeding with potential benefits to stream biodiversity
On the origin and current distribution of the Oceania Snake-Eyed Skink (Cryptoblepharus poecilopleurus) in the Hawaiian archipelago
Prioritizing the risk and management of introduced species in a landscape with high indigenous biodiversity
Assembly of the largest squamate reference genome to date: The western fence lizard, Sceloporus occidentalis
Elevated road segment (ERS) passage design may provide enhanced connectivity for amphibians, reptiles, and small mammals
Reference genome of an iconic lizard in western North America, Blainville’s horned lizard Phrynosoma blainvillii
Taxonomic reassessment of the Little pocket mouse, Perognathus longimembris (Rodentia, Heteromyidae) of southern California and northern Baja California
Skinks of Oceania, New Guinea, and Eastern Wallacea: An underexplored biodiversity hotspot
Habitat connectivity and host relatedness influence virus spread across an urbanising landscape in a fragmentation-sensitive carnivore
Harnessing island–ocean connections to maximize marine benefits of island conservation
Longman's Beaked Whale (Indopacetus pacificus) in Fiji
Genetic structure and historic demography of endangered unarmoured threespine stickleback at southern latitudes signals a potential new management approach
Science and Products
- Science
Tracking Bats and Coronaviruses
Below are the USGS 2020 Coronavirus Aid, Relief and Economic Security Act (CARES Act) research projects related to tracking bats and coronaviruses. Select tabs above for related items.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 monitoring plan to assess the status and trends of Pacific pocket mouse and identify important drivers of population dynamics...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.WERC Fire Science
WERC scientists are defining the past, present, and future of wildfires for wildlife and human communities. Explore this webpage to learn about specific, ongoing projects across California and parts of Nevada.Amphibian Research in Southern California
Amphibian populations have declined in many areas around the world. Initially, there was skepticism as to whether the observed declines were merely minor population fluctuations, but it has become increasingly clear that many declines are both real and sustained. At the request of the U.S. Department of the Interior, USGS Western Ecological Research Center (WERC) scientists are supporting the...Golden Eagles in Coastal Southern California
The status of the golden eagle (Aquila chrysaetos) in coastal southern California is unclear. To address this knowledge gap, Dr. Robert Fisher in collaboration with local, State and other Federal agencies begin a multi-year survey and tracking program of golden eagles to address questions regarding habitat use, movement behavior, nest occupancy, genetic population structure, and human impacts on...Reptile Biodiversity in the Pacific Basin Islands
Dr. Robert Fisher and his colleagues have teamed up with the U.S. Fish and Wildlife, The Nature Conservancy and multiple universities to conduct several types of studies that will address high priority issues related to reptiles in the Pacific Basin Islands. These studies will provide new information about species diversity, endemicity, biology and demography of reptile fauna and will lay the...San Diego Field Station
The San Diego Field Station is the site of research on golden eagles, endangered amphibians and reptiles, and more. Click on the "Science" tab for a comprehensive summary of this study site's projects.Elucidating mechanisms underlying amphibian declines in North America using hierarchical spatial models
Amphibian populations are declining globally at unprecedented rates but statistically rigorous identification of mechanisms is lacking. Identification of reasons underlying large-scale declines is imperative to plan and implement effective conservation efforts. Most research on amphibian population decline has focused on local populations and local factors. However, the ubiquity of declines across - Data
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Mercury concentrations in amphibian tissues across the United States, 2016-2021
Comma-separated values (.csv) file containing data related to amphibian sampling across the United States between 2016 and 2021. Data files contain mercury concentrations in amphibian and dragonfly tissues, mercury concentrations in sediment, as well as amphibian morphometrics, and habitat and climate characteristics where the samples were collected.Raster data files for Prioritizing conserved areas threatened by wildfire for monitoring and management.
The data set consists of 12 input data rasters that cover San Diego County, California. These input rasters represent criteria used in a Pareto ranking algorithm in the manuscript. These include three rasters related to fire threats, three rasters related to habitat fragmentation threats, four rasters related to species biodiversity, and two rasters related to genetic biodiversity. (see the PLOS OWestern Spadefoot Survey Data in Northern and Central California (2019)
Species distributions are governed by processes occurring at multiple spatial scales. For species with complex life cycles, the needs of all life stages must be met within the dispersal limitations of the species. Multi-scale processes can be particularly important for these species, where small-scale patterns in specific habitat components can affect the distribution of one life stage, whereas laLong-distance movements of non-migratory golden eagles in western North America, 2007-2017
We studied >500 golden eagles tracked by telemetry over a 10-year period in western North America, of which 160 engaged in non-routine, long-distance (> 300 km) movements. We identified spatial and temporal correlates of those movements at both small and large scales, and we quantified movement timing and direction. We further tested which age and sex classes of eagles were more likely to engage iDetection/non-detection data on territorial pairs of golden eagles in coastal southern California, 2016-2017
This dataset contains detection-nondetection data for territorial pairs of Golden Eagles at survey sites randomly selected from a grid of equal-sized (13.9 km2) hexagonal sample cells overlaid across the region of interest in Coastal Southern California during 2016 and 2017. We partitioned surveys within seasons based on approximate transition dates for stages in the breeding cycle of golden eagleWestern Spadefoot Habitat Selection Based on Radio Telemetry in Orange County, California 2019
We conducted a radio telemetry study of adult western spadefoots (Spea hammondii) at 2 sites in southern California to characterize their survival, behavior, and movements from breeding through aestivation to inform conservation and management for the species. These data support the following publication: Halstead, B.J., Baumberger, K.L., Backlin, A.R., Kleeman, P.M., Wong, M.N., Gallegos, E.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 projAmphibian capture mark-recapture
These data represent capture mark recapture data along with associated disease status for boreal toads (Anaxyrus boreas) from Wyoming and Montana from 2004-2016 and four frog species (Rana draytonii, R. muscosa, R. pretiosa, R. sierrae) from 2001-2016.Masticophis 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 tPredictor, null model, response variable, and habitat suitability prediction rasters for a golden eagle hierarchical Bayesian synoptic model used for habitat selection in San Diego County, California. Derived from golden eagle data collected from November
This data release includes three types of data used in habitat modeling, and predictions from the habitat models. (1) Predictor rasters for proportion urban development within 1-km radius, proportion exurban within 1-km radius, vector ruggedness measure (VRM) within 500-m radius, topographic position index (TPI) within 500-m radius. (2) Twenty-nine null models for space use for 29 different goldenMicrosatellite genotype scores for a contemporary, range-wide sample of Santa Ana sucker in southern California
These data consist of microsatellite genotype scores for all samples of Santa Ana sucker (Catostomus santaanae) used in the study. Scores represent the allele calls for each microsatellite locus (i.e. DNA fragment length containing the microsatellite repeats), with each locus containing two scores representing the two allele copies detected. Included are five tables: Full dataset (includes genotypNew record of California red-legged frogs (Rana draytonii) in Whitewater Canyon, Riverside County, CA, USA
In February 2017, a population of California red-legged frog Rana draytonii was discovered in the southern foothills of the San Bernardino Mountains of Riverside County, California, near the edge of the species historic distribution. A few days after the first sightings of R. draytonii at the Whitewater Preserve, we conducted a visual daytime search for frogs, tadpoles and egg masses followed by a - Multimedia
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Native amphibian toxin reduces invasive crayfish feeding with potential benefits to stream biodiversity
BackgroundBiodiversity is generally reduced when non-native species invade an ecosystem. Invasive crayfish, Procambarus clarkii, populate California freshwater streams, and in the Santa Monica Mountains (Los Angeles, USA), their introduction has led to trophic cascades due to omnivorous feeding behavior and a rapid rate of population growth. The native California newt, Taricha torosa, possesses aAuthorsGary M. Bucciarelli, Sierra J. Smith, Justin J. Choe, Phoebe D. Shin, Robert N. Fisher, Lee B. KatsOn the origin and current distribution of the Oceania Snake-Eyed Skink (Cryptoblepharus poecilopleurus) in the Hawaiian archipelago
Because of its extreme isolation and lack of historical connection to a mainland, the Hawaiian Archipelago is thought to have no native nonvolant terrestrial reptiles. Several squamate species have been introduced to the archipelago, likely starting with early Polynesian contact, and increasing as human traffic in the Pacific has amplified. Of the earlier introductions, one species of skink, CryptAuthorsValentina Alvarez, Samuel R Fisher, Anthony J. Barley, Kevin Donmoyer, Mozes P. K. Blom, Robert C. Thomson, Robert N. FisherPrioritizing the risk and management of introduced species in a landscape with high indigenous biodiversity
Risk analysis protocols for prioritizing the management of non-native species are numerous, yet few incorporate risk and management in the same analysis or accommodate a broad diversity of taxa outside of a specific geographic area. We adapted a protocol that accounts for these factors to address non-native animal species in the Southern California/Northern Baja California Coast Ecoregion near theAuthorsJonathan Q. Richmond, Jennifer Kingston, Brittany Ewing, Wendy M Bear, Stacie A. Hathaway, Cedric Lee, Camm C. Swift, Kristine L. Preston, Allison J. Schultz, Barbara E. Kus, Kerwin Russell, Philip Unitt, Bradford D. Hollingsworth, Robert E. Espinoza, Michael Wall, Scott Tremor, Kai Palenscar, Robert N. FisherAssembly of the largest squamate reference genome to date: The western fence lizard, Sceloporus occidentalis
Spiny lizards (genus Sceloporus) have long served as important systems for studies of behavior, thermal physiology, dietary ecology, vector biology, speciation, and biogeography. The western fence lizard, Sceloporus occidentalis, is found across most of the major biogeographical regions in the western United States and northern Baja California, Mexico, inhabiting a wide range of habitats, from graAuthorsAnusha P. Bishop, Erin P. Westeen, Michael L. Yuan, Merly Escalona, Eric Beraut, Colin Fairbairn, Mohan P. A. Marimuthu, Oanh Nguyen, Noravit Chumchim, Erin Toffelmier, Robert N. Fisher, H. Bradley Shaffer, Ian J. WangElevated 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. FisherReference genome of an iconic lizard in western North America, Blainville’s horned lizard Phrynosoma blainvillii
Genome assemblies are increasingly being used to identify adaptive genetic variation that can help prioritize the population management of protected species. This approach may be particularly relevant to species like Blainville’s horned lizard, Phrynosoma blainvillii, due to its specialized diet on noxious harvester ants, numerous adaptative traits for avoiding predation (e.g. cranial horns, dorsoAuthorsJonathan Q. Richmond, Jimmy A. McGuire, Merly Escalona, Mohan P. A. Marimuthu, Oanh Nguyen, Samuel Sacco, Eric Beraut, Erin Toffelmier, Robert N. Fisher, Ian J. Wang, H.B. ShafferTaxonomic reassessment of the Little pocket mouse, Perognathus longimembris (Rodentia, Heteromyidae) of southern California and northern Baja California
The Little pocket mouse (Perognathus longimembris) encompasses 15 to 16 currently recognized subspecies, six of which are restricted to southern California and adjacent northern Baja California. Using cranial geomorphometric shape parameters and dorsal color variables we delineate six regional groups of populations from this area that we recognize as valid, but these differ in name combination anAuthorsJames L. Patton, Robert N. FisherSkinks of Oceania, New Guinea, and Eastern Wallacea: An underexplored biodiversity hotspot
Context: Skinks comprise the dominant component of the terrestrial vertebrate fauna in Oceania, New Guinea, and Eastern Wallacea (ONGEW). However, knowledge of their diversity is incomplete, and their conservation needs are poorly understood.Aims: To explore the diversity and threat status of the skinks of ONGEW and identify knowledge gaps and conservation needs.Methods: We compiled a list of allAuthorsAlex Slavenko, Allen Allison, Christopher C. Austin, Aaron Bauer, Rafe M. Brown, Robert N. Fisher, Ivan Ineich, Bulisa Iova, Benjamin R. Karin, Frederick Kraus, Sven Mecke, Shai Meiri, Clare Morrison, Paul M. Oliver, Mark O'Shea, Jonathan Q. Richmond, Glenn M. Shea, Oliver J. S. Tallowin, David G. ChappleHabitat connectivity and host relatedness influence virus spread across an urbanising landscape in a fragmentation-sensitive carnivore
Spatially heterogeneous landscape factors such as urbanisation can have substantial effects on the severity and spread of wildlife diseases. However, research linking patterns of pathogen transmission to landscape features remains rare. Using a combination of phylogeographic and machine learning approaches, we tested the influence of landscape and host factors on feline immunodeficiency virus (FIVAuthorsChristopher P. Kozakiewicz, Christopher P. Burridge, Justin S. Lee, Simona J Kraberger, Nicholas M Fountain-Jones, Robert N. Fisher, Lisa M. Lyren, Megan K. Jennings, Seth P D Riley, Laurel E K Serieys, Meggan E. Craft, W Chris Funk, Kevin R. Crooks, Sue VandeWoude, Scott CarverHarnessing island–ocean connections to maximize marine benefits of island conservation
Islands support unique plants, animals, and human societies found nowhere else on the Earth. Local and global stressors threaten the persistence of island ecosystems, with invasive species being among the most damaging, yet solvable, stressors. While the threat of invasive terrestrial mammals on island flora and fauna is well recognized, recent studies have begun to illustrate their extended and dAuthorsStuart A. Sandin, Penny A. Becker, Ceiba Becker, Kate Brown, Natalia G. Erazo, Cielo Figuerola, Robert N. Fisher, Alan M. Friedlander, Tadashi Fukami, Nicholas A. J. Graham, Daniel S. Gruner, Nick D. Holmes, Wieteke A. Holthuijzen, Holly P. Jones, Mariela Rios, Araceli Samaniego, Wes Sechrest, Brice X. Semmens, Hazel E. Thornton, Rebecca Vega Thurber, Christy Wails, Coral A. Wolf, Brian J. ZgliczynskiLongman's Beaked Whale (Indopacetus pacificus) in Fiji
Beaked whales (Ziphidae) are the second largest family of cetaceans with 23 currently recognized species, and the Longman's beaked whale (Indopacetus pacificus) is one of the least known globally (Reeves et al., 2003; Yamada et al., 2019). Longman's beaked whales occur in tropical waters from the western Indian Ocean to the eastern Pacific (Jefferson et al., 2015), with strandings in the Pacific rAuthorsSam R Fisher, Steve Anstey, Isikeli Nasaunivalu, Robert N. FisherGenetic structure and historic demography of endangered unarmoured threespine stickleback at southern latitudes signals a potential new management approach
Habitat loss, flood control infrastructure, and drought have left most of southern California and northern Baja California's native freshwater fish near extinction, including the endangered unarmoured threespine stickleback (Gasterosteus aculeatus williamsoni). This subspecies, an unusual morph lacking the typical lateral bony plates of the G. aculeatus complex, occurs at arid southern latitudes iAuthorsRachel Turba, Jonathan Q. Richmond, Sorel Fitz-Gibbon, Marco Morselli, Robert N. Fisher, Camm C. Swift, Gorgonio Ruiz-Campos, Adam R. Backlin, Chris Dellith, David K. Jacobs - News
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