Todd Esque
Dr. Todd Esque's research interests are in disturbance ecology with emphasis in areas of community ecology, herpetology, invasive species and fire, habitat restoration, and conservation biology.
Dr. Esque's work focuses on understanding how organisms, habitats, and ecosystem processes respond to environmental change, how organisms interact to effect change, and how human-induced changes compare to the natural range of variation in arid systems. Recent work focuses on the synthesis of these experiments into regional analyses of habitat suitability and connectivity in response to global change and other anthropogenic disturbances for use by natural resource managers.
Representative studies include: projects to determine how desert tortoises, Mojave ground squirrels, golden eagles, long-lived plants, and biodiversity will respond to climate change and energy development in a rapidly changing landscape; vegetation change from fires across a 30-year chronosequence in Sonoran desert tortoise habitat; identifying habitat and health relationships for the desert tortoise, and developing a vegetation restoration program for the Mojave Desert.
Dr. Esque's projects are collaborative and interdisciplinary in nature and he is active in academic research as well as applied problems for public entities in the Department of Interior (Bureau of Land Management, National Park Service, U.S. Fish and Wildlife Service), Department of Defense, State and local governments, and private entities.
RESEARCH INTERESTS
- Arid Systems
- Conservation Biology
- Disturbance and Restoration Ecology
- Demographic and Habitat Modeling
- Community Ecology
- Invasive Species and Wildfire
- Energy Development
EDUCATION
- 2004 Ph.D. Ecology Evolution, and Conservation Biology, University of Nevada, Reno
- 1994 M.S. Zoology, Colorado State University
- 1982 B.A. Biology, Prescott College, Arizona
PROFESSIONAL AND HONORARY SOCIETIES AND SCIENCE ADVISORY COMMITTEES
- Desert Renewable Energy Conservation Plan – Science Advisory Committee 2012
- BLM – Rapid Ecoregional Assessments – lead USGS science reviewer for the Mojave and Sonoran Ecoregions 2013
PROFESSIONAL EXPERIENCE
- Research Ecologist, USGS, Western Ecological Research Center, 1997-Present
- Station Leader, USGS, St. George Field Station, 1994-1997
- Research Ecologist, USGS, Mid-continent Ecological Science Center, 1996- 1997
- Research Ecologist, National Biological Service (Survey), Mid-continent Ecological Science Center, 1993 - 1996
- Ecologist, Bureau of Land Management, Dixie Resource Area, Utah, 1993 - 1993
- Research Technician, Fish and Wildlife Service, Region 8, Research, Ft. Collins, CO 1986-1993
Science and Products
Golden Eagle Food Habits in the Mojave Desert: Regional information for a changing landscape.
Estimates of pathogen exposure predict varying transmission likelihood: Host contact and shedding patterns may clarify disease dynamics in desert tortoises Gopherus agassizii
Integrating telemetry data at several scales with spatial capture–recapture to improve density estimates
Local climate adaptations in two ubiquitous Mojave Desert shrub species, Ambrosia dumosa and Larrea tridentata
Borreliosis transmission from ticks to humans associated with desert tortoise burrows: Examples of tick-borne relapsing fever in the Mojave Desert
Linking behavioral states to landscape features for improved conservation management
Assessment of disease risk associated with potential removal of anthropogenic barriers to Mojave desert tortoise (Gopherus agassizii) population connectivity
Priority species lists to restore desert tortoise and pollinator habitats in Mojave Desert shrublands
Connectivity of Mojave Desert tortoise populations—Management implications for maintaining a viable recovery network
Comparing sample bias correction methods for species distribution modeling using virtual species
‘Unscrambling’ the drivers of egg production in Agassiz’s desert tortoise: Climate and individual attributes predict reproductive output
Using movement to inform conservation corridor design for Mojave desert tortoise
Harnessing landscape genomics to identify future climate resilient genotypes in a desert annual
Immune and sex-biased gene expression in the threatened Mojave desert tortoise, Gopherus agassizii
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Golden Eagle Food Habits in the Mojave Desert: Regional information for a changing landscape.
Expansion of renewable energy development is rapidly transforming the Mojave Desert landscape and has the potential to impact Golden Eagles through loss of foraging habitat and reduced prey base. Regional information on Golden Eagle food habits is limited and little is known of how dietary variability influences eagle productivity. We examined diet using motion activated trail cameras and collectiEstimates of pathogen exposure predict varying transmission likelihood: Host contact and shedding patterns may clarify disease dynamics in desert tortoises Gopherus agassizii
These datasets (S1-S4) document the transmission of a bacterial pathogen (Mycoplasma agassizii) between desert tortoises (Gopherus agassizii). The desert tortoises were experimentally introduced in captivity and were used to create and compare models predicting transmission probability given data on the hosts and their interactions. Datasets S1 & S2 include variables describing the individual tort - Multimedia
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Filter Total Items: 142
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 violations of statistical assumptions, which have the poteAuthorsCorey I Mitchell, Kevin T. Shoemaker, Todd C. Esque, A. G. Vandergast, Steven J. Hromada, Kirsten E. Dutcher, Jill S. Heaton, Kenneth E. NussearLocal climate adaptations in two ubiquitous Mojave Desert shrub species, Ambrosia dumosa and Larrea tridentata
Widely distributed species are often locally adapted to climate gradients across their ranges. But little is known about the patterns of intraspecific adaptation in desert shrubs.We examined the questions of local adaptation in multiple populations of two common shrub species of the winter-wet Mojave Desert in North America in a multiple common garden experiment. Plants were raised in the greenhouAuthorsNathan A. Custer, Susan Schwinning, Lesley A. DeFalco, Todd C. EsqueBorreliosis transmission from ticks to humans associated with desert tortoise burrows: Examples of tick-borne relapsing fever in the Mojave Desert
Ticks transmit pathogens and parasitize wildlife in turn causing zoonotic diseases in many ecosystems. Argasid ticks, such as Ornithodoros spp., harbor and transmit Borrelia spp., resulting in tick-borne relapsing fever (TBRF) in people. In the western United States, TBRF is typically associated with the bite of an infected Ornithodoros hermsi tick found in habitats at high elevations (>1500 ft).AuthorsMolly J Bechtel, K. Kristina Drake, Todd C. Esque, Nathan C Nieto, Jeffrey T. Foster, Mike B TeglasLinking behavioral states to landscape features for improved conservation management
A central theme for conservation is understanding how animals differentially use, and are affected by change in, the landscapes they inhabit. However, it has been challenging to develop conservation schemes for habitat-specific behaviors.Here we use behavioral change point analysis to identify behavioral states of golden eagles (Aquila chrysaetos) in the Sonoran and Mojave Deserts of the southwestAuthorsMaitreyi Sur, Brian Woodbridge, Todd C. Esque, Jim R Belthoff, Peter H. Bloom, Robert N. Fisher, Kathleen Longshore, Kenneth E. Nussear, Jeff A. Tracey, Melissa A. Braham, Todd E. KatznerAssessment of disease risk associated with potential removal of anthropogenic barriers to Mojave desert tortoise (Gopherus agassizii) population connectivity
The Mojave Desert tortoise (Gopherus agassizii), federally listed as threatened, has suffered habitat loss and fragmentation due to human activities. Upper respiratory tract disease (URTD), a documented health threat to desert tortoises, has been detected at the Large-Scale Translocation Study Site (LSTS) in southwestern Nevada, US, a fenced recipient site for translocated animals. Our study aimedAuthorsTristan L. Burgess, Josephine Braun, Carmel L Witte, Nadine Lamberski, Field. Kimberleigh J, Linda J. Allison, Roy C. Averill-Murray, K. Kristina Drake, Kenneth E. Nussear, Todd C. Esque, Bruce A RideoutPriority species lists to restore desert tortoise and pollinator habitats in Mojave Desert shrublands
Mojave Desert shrublands are home to unique plants and wildlife and are experiencing rapid habitat change due to unprecedented large-scale disturbances; yet, established practices to effectively restore disturbed landscapes are not well developed. A priority species list of native plant taxa was developed to guide seed collectors, commercial growers, resource managers, and restoration practitionerAuthorsTodd C. Esque, Lesley A. DeFalco, Gayle Loren Tyree, K. Kristina Drake, Kenneth E. Nussear, Joseph S WilsonConnectivity of Mojave Desert tortoise populations—Management implications for maintaining a viable recovery network
Executive SummaryThe historic distribution of Mojave desert tortoises (Gopherus agassizii) was relatively continuous across the range, and the importance of tortoise habitat outside of designated tortoise conservation areas (TCAs) to recovery has long been recognized for its contributions to supporting gene flow between TCAs and to minimizing impacts and edge effects within TCAs. However, connectiAuthorsRoy C. Averill-Murray, Todd C. Esque, Linda J. Allison, Scott Bassett, Sarah K. Carter, Kirsten E. Dutcher, Steven J. Hromada, Kevin T. Shoemaker, Kenneth E. NussearComparing sample bias correction methods for species distribution modeling using virtual species
A key assumption in species distribution modeling (SDM) with presence‐background (PB) methods is that sampling of occurrence localities is unbiased and that any sampling bias is proportional to the background distribution of environmental covariates. This assumption is rarely met when SDM practitioners rely on federated museum records from natural history collections for geo‐located occurrences duAuthorsRich Inman, Janet Franklin, Todd C. Esque, Kenneth E. Nussear‘Unscrambling’ the drivers of egg production in Agassiz’s desert tortoise: Climate and individual attributes predict reproductive output
ABSTRACT: The ‘bet hedging’ life history strategy of long-lived iteroparous species reduces short-term reproductive output to minimize the risk of reproductive failure over a lifetime. For desert-dwelling ectotherms living in variable and unpredictable environments, reproductive output is further influenced by precipitation and temperature via effects on food availability and limits on activity. WAuthorsCorey I. Mitchell, Derek Friend, Lauren T. Phillips, Elizabeth A. Hunter, Jeffrey E. Lovich, Mickey Agha, Shellie R. Puffer, Kristy L. Cummings, Philip A. Medica, Todd C. Esque, Kenneth E. Nussear, Kevin T. ShoemakerUsing movement to inform conservation corridor design for Mojave desert tortoise
BackgroundPreserving corridors for movement and gene flow among populations can assist in the recovery of threatened and endangered species. As human activity continues to fragment habitats, characterizing natural corridors is important in establishing and maintaining connectivity corridors within the anthropogenic development matrix. The Mojave desert tortoise (Gopherus agassizii) is a threatenedAuthorsSteven J. Hromada, Todd C. Esque, Amy G. Vandergast, Kirsten E. Dutcher, Corey I Mitchell, Miranda E Gray, Tony Chang, Brett G. Dickson, Kenneth E. NussearHarnessing landscape genomics to identify future climate resilient genotypes in a desert annual
Local adaptation features critically in shaping species responses to changing environments, complicating efforts to revegetate degraded areas. Rapid climate change poses an additional challenge that could reduce fitness of even locally sourced seeds in restoration. Predictive restoration strategies that apply seeds with favourable adaptations to future climate may promote long‐term resilience. LanAuthorsDaniel F. Shryock, Loraine K Washburn, Lesley A. DeFalco, Todd C. EsqueImmune and sex-biased gene expression in the threatened Mojave desert tortoise, Gopherus agassizii
The immune system of ectotherms, particularly non-avian reptiles, remains poorly characterized regarding the genes involved in immune function, and their function in wild populations. We used RNA-Seq to explore the systemic response of Mojave desert tortoise (Gopherus agassizii) gene expression to three levels of Mycoplasma infection to better understand the host response to this bacterial pathogeAuthorsCindy Xu, Greer A. Dolby, K. Kristina Drake, Todd C. Esque, Kenro Kusumi - Web Tools
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