Robert N Fisher
Biography
Dr. Robert Fisher is a conservation biologist with the US 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.
EDUCATION
- 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
RESEARCH INTERESTS
- Conservation biology
- Biogeography
- Modelling
- Natural history
- Speciation
- Invasive species
- Climate variability
- Anthropocene
Science and Products
Evolutionary dynamics of a rapidly receding southern range boundary in the threatened California red-legged frog (Rana draytonii)
Populations forming the edge of a species range are often imperiled by isolation and low genetic diversity, with proximity to human population centers being a major determinant of edge stability in modern landscapes. Since the 1960s, the California red-legged frog (Rana draytonii) has undergone extensive declines in heavily urbanized southern...
Richmond, Jonathan Q.; Barr, Kelly R.; Backlin, Adam R.; Vandergast, Amy G.; Fisher, Robert N. A new species of Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae) from Carlia spp. (Sauria: Scincidae) from Papua New Guinea
A new species of Eimeria Schneider, 1875 from rainbow skinks, Carlia ailanpalai Zug and Carlia eothen Zug is described from specimens collected in Papua New Guinea (PNG). Oöcysts of Eimeria zugi n. sp. from one of one (100%) C. eothen are ellipsoidal to cylindroidal, with a smooth, colourless, bi-layered wall, measure 25.1 × 15.5 μm and have a...
McAllister, Chris T.; Duszynski, Donald W.; Fisher, Robert N.; Austin, Christopher C. Effects of natural flooding and manual trapping on the facilitation of invasive crayfish-native amphibian coexistence in a semi-arid perennial stream
Aquatic amphibians are known to be vulnerable to a myriad of invasive predators. Invasive crayfish are thought to have eliminated native populations of amphibians in some streams in the semi-arid Santa Monica Mountains of southern California. Despite their toxic skin secretions that defend them from native predators, newts are vulnerable to...
Kats, Lee B.; Bucciarelli, Gary; Vandergon, Thomas L.; Honeycutt, Rodney L.; Mattiasen, Evan; Sanders, Arthur; Riley, Seth P.D.; Kerby, Jacob L.; Fisher, Robert N. Comparative phylogeography reveals deep lineages and regional evolutionary hotspots in the Mojave and Sonoran Deserts
Aim: We explored lineage diversification within desert-dwelling fauna. Our goals were (1) to determine whether phylogenetic lineages and population expansions were consistent with younger Pleistocene climate fluctuation hypotheses or much older events predicted by pre-Pleistocene vicariance hypotheses, (2) to assess concordance in spatial patterns...
Wood, Dustin A.; Vandergast, Amy G.; Barr, Kelly R.; Inman, Richard D.; Esque, Todd C.; Nussear, Kenneth E.; Fisher, Robert N. Trends in amphibian occupancy in the United States
Though a third of amphibian species worldwide are thought to be imperiled, existing assessments simply categorize extinction risk, providing little information on the rate of population losses. We conducted the first analysis of the rate of change in the probability that amphibians occupy ponds and other comparable habitat features across the...
Adams, M.J.; Miller, David A.W.; Muths, Erin; Corn, Paul Stephen; Grant, Evan H. Campbell; Bailey, Larissa L.; Fellers, Gary M.; Fisher, Robert N.; Sadinski, Walter J.; Waddle, Hardin; Walls, Susan C. Evolutionary hotspots in the Mojave Desert
Genetic diversity within species provides the raw material for adaptation and evolution. Just as regions of high species diversity are conservation targets, identifying regions containing high genetic diversity and divergence within and among populations may be important to protect future evolutionary potential. When multiple co-distributed...
Vandergast, Amy G.; Inman, Richard D.; Barr, Kelly R.; Nussear, Kenneth E.; Esque, Todd C.; Hathaway, Stacie A.; Wood, Dustin A.; Medica, Philip A.; Breinholt, Jesse W.; Stephen, Catherine L.; Gottscho, Andrew D.; Marks, Sharyn B.; Jennings, W. Bryan; Fisher, Robert N. Mapping behavioral landscapes for animal movement: a finite mixture modeling approach
Because of its role in many ecological processes, movement of animals in response to landscape features is an important subject in ecology and conservation biology. In this paper, we develop models of animal movement in relation to objects or fields in a landscape. We take a finite mixture modeling approach in which the component densities are...
Tracey, Jeff A.; Zhu, Jun; Boydston, Erin E.; Lyren, Lisa M.; Fisher, Robert N.; Crooks, Kevin R. Three new species of Coccidia (Apicomplexa: Eimeriidae) from Skinks, Lipinia spp. (Sauria: Scincidae), from Oceania
Between September 1991 and March 1993, 25 moth skinks (Lipinia noctua) were collected from various localities on the Cook Islands, Fiji, Papua New Guinea (PNG), and Vanuatu and examined for coccidians. In addition, a single Roux's lipinia skink (Lipinia rouxi) was collected from PNG and examined for coccidia. Sixteen (64%) L. noctua were found to...
McAllister, Chris T.; Duszynski, Donald W.; Austin, Christopher C.; Fisher, Robert N. Joint estimation of habitat dynamics and species interactions: Disturbance reduces co-occurrence of non-native predators with an endangered toad
1. Ecologists have long been interested in the processes that determine patterns of species occurrence and co-occurrence. Potential short-comings of many existing empirical approaches that address these questions include a reliance on patterns of occurrence at a single time point, failure to account properly for imperfect detection and treating...
Miller, David A.W.; Brehme, Cheryl S.; Hines, James E.; Nichols, James D.; Fisher, Robert N. Urban habitat fragmentation and genetic population structure of bobcats in coastal southern California
Although habitat fragmentation is recognized as a primary threat to biodiversity, the effects of urban development on genetic population structure vary among species and landscapes and are not yet well understood. Here we use non-invasive genetic sampling to compare the effects of fragmentation by major roads and urban development on levels of...
Ruell, E.W.; Riley, S.P.D.; Douglas, M.R.; Antolin, M.F.; Pollinger, J.R.; Tracey, J.A.; Lyren, L.M.; Boydston, E.E.; Fisher, R.N.; Crooks, K.R. Effects of spatial subsidies and habitat structure on the foraging ecology and size of geckos
While it is well established that ecosystem subsidies—the addition of energy, nutrients, or materials across ecosystem boundaries—can affect consumer abundance, there is less information available on how subsidy levels may affect consumer diet, body condition, trophic position, and resource partitioning among consumer species. There is also little...
Briggs, Amy A.; Young, Hillary S.; McCauley, Douglas J.; Hathaway, Stacie A.; Dirzo, Rodolfo; Fisher, Robert N. Cryptic extinction of a common Pacific lizard Emoia impar (Squamata, Scincidae) from the Hawaiian Islands.
Most documented declines of tropical reptiles are of dramatic or enigmatic species. Declines of widespread species tend to be cryptic. The early (1900s) decline and extinction of the common Pacific skink Emoia impar from the Hawaiian Islands is documented here through an assessment of literature, museum vouchers and recent fieldwork. This decline...
Fisher, Robert; Ineich, Ivan