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.
- Arid Systems
- Conservation Biology
- Disturbance and Restoration Ecology
- Demographic and Habitat Modeling
- Community Ecology
- Invasive Species and Wildfire
- Energy Development
- 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
- 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
Desert landscapes are rapidly changing due to increases in invasive plant species, frequency of wildfires, urban and energy development, recreational use, military training, and climate variation. Dr. Todd Esque, USGS researchers, and collaborators are working together to investigate these changes and provide managers with key information that can be used to manage natural resources more effectively.
The desert tortoise is listed as “threatened” under the Endangered Species Act. USGS WERC scientists, along with project partners have been conducting long-term analyses on how changes in the southwestern deserts of the United States can affect desert tortoise populations. Dr. Todd Esque and his team are investigating how habitat disturbances and restoration projects influence tortoise populations through research in nutrition, physiology, epidemiology, genetics, and demographics.
The southwestern desert region is home to many sensitive species. Species are at-risk due to past, present, and future changes to the landscape. WERC’s Dr. Todd Esque, field researchers, and collaborators are using models, monitoring plans, and decision-support tools to provide land managers with the resources they need to answer questions about how environmental change influences plants, animals, and their habitats. Species and habitat modeling are powerful tools used by researchers to answer natural resource management questions. Dr. Todd Esque and WERC researchers use a variety of geospatial modeling approaches to understand the dynamics of arid ecosystems and how environmental changes affect our public lands. We use models to assist in identifying plant and animal priority sites, species and communities that are vulnerable to climate change, produce high quality habitat models for managing species of concern, and investigate ecosystem responses to land use change and climate change.
The Henderson Field Station supports research scientists leading projects in desert ecosystem restoration, genetics of iconic trees of the Mojave Desert, predator-prey studies on protected lands, and more. Select the next tab for a comprehensive summary of studies at this site.
An assessment of food habits, prey availability, and nesting success of golden eagles within the Desert Renewable Energy Conservation Plan Area
Within the Desert Renewable Energy Conservation Plan area, which encompasses California’s Mojave Desert, development and operation of renewable energy facilities has the potential to impact golden eagle (Aquila chrysaetos) populations through loss of habitat and prey base. Developing an effective conservation strategy that aims to mitigate for...Longshore, Kathleen M.; Esque, Todd; Nussear, Kenneth E.; Johnson, Diego R.; Simes, Matthew; Inman, Rich
Coupling gene-based and classic veterinary diagnostics improves interpretation of health and immune function in the Agassiz’s desert tortoise (Gopherus agassizii)
The analysis of blood constituents is a widely used tool to aid in monitoring of animal health and disease. However, classic blood diagnostics (i.e. hematologic and plasma biochemical values) often do not provide sufficient information to determine the state of an animal’s health. Field studies on wild tortoises and other reptiles have had limited...Drake, Karla K.; Bowen, Lizabeth; Lewison, Rebecca L.; Esque, Todd C.; Nussear, Kenneth E.; Braun, Josephine; Waters, Shannon C.; Miles, A. Keith
Drawing a line in the sand: Effectiveness of off-highway vehicle management in California's Sonoran desert
Public land policies manage multiple uses while striving to protect vulnerable plant and wildlife habitats from degradation; yet the effectiveness of such policies are infrequently evaluated, particularly for remote landscapes that are difficult to monitor. We assessed the use and impacts of recreational vehicles on Mojave Desert washes (...Custer, Nathan; Defalco, Lesley A.; Nussear, Kenneth E.; Esque, Todd C.
Common Raven (Corvus corax) kleptoparasitism at a Golden Eagle (Aquila chyrsaetos) nest in southern Nevada
The Common Raven (Corvus corax) is a ubiquitous species in the Mojave Desert of southern Nevada and California. From 5 to 24 May 2014, using remote trail cameras, we observed ravens repeatedly kleptoparasitizing food resources from the nest of a pair of Golden Eagles (Aquila chyrsaetos) in the Spring Mountains of southern Nevada. The ravens fed on...Simes, Matthew; Johnson, Diego R.; Streit, Justin; Longshore, Kathleen M.; Nussear, Kenneth E.; Esque, Todd C.
Habitat drives dispersal and survival of translocated juvenile desert tortoises
1.In spite of growing reliance on translocations in wildlife conservation, translocation efficacy remains inconsistent. One factor that can contribute to failed translocations is releasing animals into poor quality or otherwise inadequate habitat. 2.Here we used a targeted approach to test the relationship of habitat features to post-translocation...Nafus, Melia G.; Esque, Todd C.; Averill-Murray, Roy C.; Nussear, Kenneth E.; Swaisgood, Ronald R.
Landscape genetic approaches to guide native plant restoration in the Mojave Desert
Restoring dryland ecosystems is a global challenge due to synergistic drivers of disturbance coupled with unpredictable environmental conditions. Dryland plant species have evolved complex life-history strategies to cope with fluctuating resources and climatic extremes. Although rarely quantified, local adaptation is likely widespread among these...Shryock, Daniel F.; Havrilla, Caroline A.; DeFalco, Lesley; Esque, Todd C.; Custer, Nathan; Wood, Troy E.
Negative impacts of invasive plants on conservation of sensitive desert wildlife
Habitat disturbance from development, resource extraction, off-road vehicle use, and energy development ranks highly among threats to desert systems worldwide. In the Mojave Desert, United States, these disturbances have promoted the establishment of nonnative plants, so that native grasses and forbs are now intermixed with, or have been replaced...Drake, K. Kristina; Bowen, Lizabeth; Nussear, Kenneth E.; Esque, Todd C.; Berger, Andrew J.; Custer, Nathan; Waters, Shannon C.; Johnson, Jay D.; Miles, A. Keith; Lewison, Rebecca L.
Comparison of methods to monitor the distribution and impacts of unauthorized travel routes in a border park
The distribution and abundance of human-caused disturbances vary greatly through space and time and are cause for concern among land stewards in natural areas of the southwestern border-lands between the USA and Mexico. Human migration and border protection along the international boundary create Unauthorized Trail and Road (UTR) networks across...Esque, Todd C.; Inman, Rich; Nussear, Kenneth E.; Webb, Robert; Girard, M.M.; DeGayner, J.
Impacts of climate change and renewable energy development on habitat of an endemic squirrel, Xerospermophilus mohavensis, in the Mojave Desert, USA
Predicting changes in species distributions under a changing climate is becoming widespread with the use of species distribution models (SDMs). The resulting predictions of future potential habitat can be cast in light of planned land use changes, such as urban expansion and energy development to identify areas with potential conflict. However,...Inman, Richard D.; Esque, Todd C.; Nussear, Kenneth E.; Leitner, Philip; Matocq, Marjorie D.; Weisberg, Peter J.; Dilts, Thomas E.
Inferring social structure and its drivers from refuge use in the desert tortoise, a relatively solitary species
For several species, refuges (such as burrows, dens, roosts, nests) are an essential resource for protection from predators and extreme environmental conditions. Refuges also serve as focal sites for social interactions, including mating, courtship, and aggression. Knowledge of refuge use patterns can therefore provide information about social...Sah, Pratha; Nussear, Kenneth E.; Esque, Todd C.; Aiello, Christina M.; Hudson, Peter J.; Bansal, Shweta
Multi-scale connectivity and graph theory highlight critical areas for conservation under climate change
Conservation planning and biodiversity management require information on landscape connectivity across a range of spatial scales from individual home ranges to large regions. Reduction in landscape connectivity due changes in land-use or development is expected to act synergistically with alterations to habitat mosaic configuration arising from...Dilts, Thomas E.; Weisberg, Peter J.; Leitner, Phillip; Matocq, Marjorie D.; Inman, Richard D.; Nussear, Ken E.; Esque, Todd C.
Host contact and shedding patterns clarify variation in pathogen exposure and transmission in threatened tortoise Gopherus agassizii: implications for disease modelling and management
Summary Most directly transmitted infections require some form of close contact between infectious and susceptible hosts to spread. Often disease models assume contacts are equal and use mean field estimates of transmission probability for all interactions with infectious hosts. Such methods may inaccurately describe transmission when...Aiello, Christina M.; Nussear, Kenneth E.; Esque, Todd C.; Emblidge, Patrick G.; Sah, Pratha; Bansal, Shweta; Hudson, Peter J.
This short video features incredible and graphic images and video of golden eagle prey. These birds are eating machines. USGS biologist-rock climbers install nest cameras to study the eating habits of golden eagles and their young in the Mojave Desert. This work goes towards creating a Prey Availability Habitat Model to better site green energy projects so that they will have the least impact on golden eagles. The majority of this video is Public Domain with exception to the specific shots listed as owned by the copyright holders.
"The Heat is On: Desert Tortoises and Survival" is a thirty minute television program exploring the world of the Mojave Desert Tortoise. It highlights the USGS research program on the Desert Tortoise and the role of that research in managing desert environments to allow the species to recover and escape the threat of extinction. The program was originally released on the internet in segmented form in 2010. This re-release presents the program in its entirety.
The program was produced jointly by the USGS Western Ecological Research Center (www.werc.usgs.gov) in cooperation with the US Fish and Wildlife Service, Desert Tortoise Recovery Office.
Perhaps some of you have already experienced a sweet smooch or two under the holiday mistletoe, enjoying this fairly old kissing ritual for people. While figuring prominently in ancient lore, mistletoe is important in other vital ways: it provides essential food, cover and nesting sites for an amazing number of critters. In fact, some animals couldn’t even survive without mistletoe.