Dr. Erin Muths is a Research Zoologist at the Fort Collins Science Center who specializes in amphibian demography, disease ecology and conservation.
Dr. Muths holds a doctorate in Zoology from the University of Queensland, Australia. Since joining the USGS in 1995, she has studied amphibians in Colorado and around the world. Dr. Muths specializes in amphibian demography, disease ecology and conservation. Current research projects include reintroductions of boreal toads in Rocky Mountain National Park, demography of chorus frog and boreal toad populations in Colorado and Wyoming, and salamander disease and occurrence in the desert southwest and Mexico. She is on several graduate student committees at Colorado State University, the University of Colorado and at the CCMB Laboratory for Conservation of Endangered Species in Hyderabad, India.
Professional Experience
U.S. Geological Survey - Biological Resources Division Fort Collins Science Center, Fort Collins, CO, April 1995 - present
University of Queensland Brisbane, Australia; Southwest Queensland, Australia, Ph.D. research, June 1991 - January 1995
Archbold Biological Station Lake Placid, FL, Research Intern, October 1990 - March 1991
Kansas State University, Division of Biology Manhattan, KS, Master's Research, Research Assistant, August 1988 - May 1990
Smithsonian Institution, Conservation Research Center Front Royal, VA, Intern, December 1987 - March 1988
Affiliations and Memberships*
USGS Amphibian Research and Monitoring Initiative - Principle Investigator, Southern Rocky Mountains, 2000 - present
The Society for Conservation Biology, 1989 – 2011
The American Society of Mammalogists, 1994 – 2002
Colorado Boreal Toad Recovery Team, 1996 – present
Society for Northwestern Vertebrate Biology 1997 – 2007
Research Associate – Denver Zoological Foundation, 1998 – present
Partners in Amphibian and Reptile Conservation, 1999 – present; SW PARC – Steering Committee, 2008 – 2011
Society for the Study of Amphibians and Reptiles, 2000 – 2014; representative to joint Herpetological Education Committee, 2017 – 2020; Committee chair 2020
Co-Editor, Journal of Herpetology, 2010 – 2015; Section Editor, Journal of Herpetology, 2014 – present
American Society of Ichthyologists & Herpetologists, 2002 – present
Herpetologists’ League 2007 – present; Executive Council 2007 – 2011; Chair, EE Williams Research Grant Committee, 2009-2010
Science and Products
A Framework for Guiding Management Decisions for Amphibians in an Uncertain Future
Modeling Colonization of a Population of Chiricahua Leopard Frogs
Amphibian Chytrid Fungus Sampling in Arizona and Mexico
Species Conservation
Amphibian Research and Monitoring Initiative: Rocky Mountain Region
Elucidating mechanisms underlying amphibian declines in North America using hierarchical spatial models
Handling times: tagging vs photos, Boreal toads in WY/CO 2020
Chorus frog density and population growth, Cameron Pass, Colorado, 1986-2020
Boreal toad metamorph capture, recapture and covariates data, Colorado 2017-2018
Capture-recapture, disease and covariate data for boreal toads from Blackrock Wyoming 2019
Amphibian capture mark-recapture
Amphibian Occupancy and Effects of Habitat Use on Pesticide Exposure in Iowa Wetlands
Demography and habitat use of boreal toads (Anaxyrus boreas) and other amphibians in northern Wyoming (Blackrock).
Empirical evidence for effects of invasive American Bullfrogs on occurrence of native amphibians and emerging pathogens
Looking ahead, guided by the past: The role of U.S. national parks in amphibian research and conservation
Thermal conditions predict intraspecific variation in senescence rate in frogs and toads
Distribution of tiger salamanders in northern Sonora, Mexico: Comparison of sampling methods and possible implications for an endangered subspecies
Staggered-entry analysis of breeding phenology and occupancy dynamics of Arizona toads from historically occupied habitats of New Mexico, USA
Amphibian population responses to mitigation: Relative importance of wetland age and design
Accommodating the role of site memory in dynamic species distribution models
Why disease ecology needs life-history theory: A host perspective
Density dependence and adult survival drive the dynamics in two high elevation amphibian populations
Batrachochytrium salamandrivorans (Bsal) not detected in an intensive survey of wild North American amphibians
Informing amphibian conservation efforts with abundance-based metapopulation models
Effects of snowpack, temperature, and disease on the demography of a wild population of amphibians
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Science
A Framework for Guiding Management Decisions for Amphibians in an Uncertain Future
Amphibians are a group of animals facing especially severe declines due to many factors including climate change and a common pathogen, the amphibian chytrid fungus. To make informed decisions about amphibians, wildlife managers need to identify species facing the greatest threats and the actions that will most effectively minimize impacts of those threats. Although some amphibian species are relaModeling Colonization of a Population of Chiricahua Leopard Frogs
Managing a species with intensive tools like reintroduction may focus on single sites or entire landscapes. For mobile species like the federally-threatened Chiricahua leopard frog (Lithobates chiricahuensis [CLF]), both suitable colonization sites and suitable dispersal corridors between sites are needed. Following the eradication of the invasive American bullfrog (Lithobates catesbeianus) from...Amphibian Chytrid Fungus Sampling in Arizona and Mexico
Information on disease presence can be of use to natural resource managers, especially in areas supporting threatened and endangered species that occur coincidentally with species that are suspected vectors for disease. A general sense of pathogen presence (or absence) can inform management directed at threatened and endangered species, especially in regions where disease is suspected to have...Species Conservation
Large scale changes are occurring to our natural landscapes, often resulting in changes to the distribution and abundance of species living within these landscapes. Populations of many species affected by these natural or anthropogenic changes require focused management to ensure their conservation and sometimes recovery from the brink of extinction.Amphibian Research and Monitoring Initiative: Rocky Mountain Region
The Rocky Mountain Region of Amphibian Research and Monitoring Initiative (ARMI) encompasses Montana, Wyoming, Colorado, and New Mexico. Two USGS Science Centers initiate and develop ARMI projects in this region. Investigations at NOROCK are headed by Dr. Blake Hossack. Investigations at the Fort Collins Science Center (FORT), Colorado, are headed by Dr. Erin Muths. The ARMI program is based on a...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
Handling times: tagging vs photos, Boreal toads in WY/CO 2020
Individual identification is required for investigations that examine population-level changes (e.g., decreased survival, increased disease prevalence) and the mechanisms associated with these changes in wild populations. Such identification generally requires the application of a unique mark, or the documentation of characteristics unique to each individual animal. Marking strategies that minimizChorus frog density and population growth, Cameron Pass, Colorado, 1986-2020
We investigated population dynamics in chorus frogs (Pseudacris maculata) relative to extrinsic (air temperatures and snowpack) and intrinsic (density dependence) characteristics at 2 sites in Colorado, USA. We used capture-mark-recapture (cmr) data (i.e., 1 or 0, provided here) and a Bayesian model framework to assess our a priori hypotheses about interactions among covariates and chorus frog surBoreal toad metamorph capture, recapture and covariates data, Colorado 2017-2018
This dataset includes two files, 1) site -specific covariates including the presence of predators (fish), disease (Batrachochytrium dendrobatidis [Bd] - amphibian chytrid fungus), and permanence (ephemeral or permanent) of sites in Rocky Mountain National Park, Colorado. The dataset was analyzed for planned publication of a manuscript in Population Ecology, Crockett, J., E. Muths and L.L. Bailey aCapture-recapture, disease and covariate data for boreal toads from Blackrock Wyoming 2019
We investigated population dynamics in boreal toads relative to abiotic (fall temperatures and snowpack -the covariates provided here) and biotic (the abundance of another anuran host,data provide here) characteristics of the local environment at 6 sites in Wyoming, USA. We used capture-recapture data (i.e., 1 or 0, provided here) and a robust design multi-state model framework that incorporates dAmphibian 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.Amphibian Occupancy and Effects of Habitat Use on Pesticide Exposure in Iowa Wetlands
Amphibians living in agricultural areas encounter many challenges. Two factors affecting individuals in these landscapes are habitat loss and pesticides. This thesis focuses on amphibians using agricultural wetlands in Iowa, where row crops such as corn and soybeans dominate the landscape. The goal of my first study was to determine the influences of site characteristics on amphibian presence andDemography and habitat use of boreal toads (Anaxyrus boreas) and other amphibians in northern Wyoming (Blackrock).
Amphibian decline is a problem of global importance, with over 40% of species considered at risk. This phenomenon is not limited to the tropics or to other countries. Amphibian species in the U.S. are also declining, contributing to the larger, global phenomenon. For example, in the State of Wyoming, the Wyoming toad has been extirpated in the wild and the boreal toad is a species of special conce - Publications
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Empirical evidence for effects of invasive American Bullfrogs on occurrence of native amphibians and emerging pathogens
Invasive species and emerging infectious diseases are two of the greatest threats to biodiversity. American Bullfrogs (Rana [Lithobates] catesbeiana), which have been introduced to many parts of the world, are often linked with declines of native amphibians via predation and spreading emerging pathogens such as amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]) and ranaviruses. AlthougLooking ahead, guided by the past: The role of U.S. national parks in amphibian research and conservation
Protected areas like national parks are essential elements of conservation because they limit human influence on the landscape, which protects biodiversity and ecosystem function. The role of national parks in conservation, however, often goes far beyond limiting human influence. The U.S. National Park Service and its system of land units contribute substantively to conservation by providing proteThermal conditions predict intraspecific variation in senescence rate in frogs and toads
Variation in temperature is known to influence mortality patterns in ectotherms. Even though a few experimental studies on model organisms have reported a positive relationship between temperature and actuarial senescence (i.e., the increase in mortality risk with age), how variation in climate influences the senescence rate across the range of a species is still poorly understood in free-rangingDistribution of tiger salamanders in northern Sonora, Mexico: Comparison of sampling methods and possible implications for an endangered subspecies
Many aquatic species in the arid USA-Mexico borderlands region are imperiled, but limited information on distributions and threats often hinders management. To provide information on the distribution of the Western Tiger Salamander (Ambystoma mavortium), including the USA-federally endangered Sonoran Tiger Salamander (Ambystoma mavortium stebbinsi), we used traditional (seines, dip-nets) and moderStaggered-entry analysis of breeding phenology and occupancy dynamics of Arizona toads from historically occupied habitats of New Mexico, USA
For species with variable phenology, it is often challenging to produce reliable estimates of population dynamics or changes in occupancy. The Arizona Toad (Anaxyrus microscaphus) is a southwestern USA endemic that has been petitioned for legal protection, but status assessments are limited by a lack of information on population trends. Also, timing and consistency of Arizona Toad breeding variesAmphibian population responses to mitigation: Relative importance of wetland age and design
Wetland creation is a common practice to mitigate for the loss of natural wetlands. However, there is still uncertainty about how effectively created wetlands replace habitat provided by natural wetlands. This uncertainty is due in part because post-construction monitoring of biological communities, and vertebrates especially, is rare and typically short-term (Accommodating the role of site memory in dynamic species distribution models
First-order dynamic occupancy models (FODOMs) are a class of state-space model in which the true state (occurrence) is observed imperfectly. An important assumption of FODOMs is that site dynamics only depend on the current state and that variations in dynamic processes are adequately captured with covariates or random effects. However, it is often difficult to understand and/or measure the covariWhy disease ecology needs life-history theory: A host perspective
When facing an emerging infectious disease of conservation concern, we often have little information on the nature of the host‐parasite interaction to inform management decisions. However, it is becoming increasingly clear that the life‐history strategies of host species can be predictive of individual‐ and population‐level responses to infectious disease, even without detailed knowledge on the spDensity dependence and adult survival drive the dynamics in two high elevation amphibian populations
Amphibian conservation has progressed from the identification of declines to mitigation, but efforts are hampered by the lack of nuanced information about the effects of environmental characteristics and stressors on mechanistic processes of population regulation. Challenges include a paucity of long-term data and scant information about the relative roles of extrinsic (e.g., weather) and intrinsiBatrachochytrium salamandrivorans (Bsal) not detected in an intensive survey of wild North American amphibians
The salamander chytrid fungus (Batrachochytrium salamandrivorans [Bsal]) is causing massive mortality of salamanders in Europe. The potential for spread via international trade into North America and the high diversity of salamanders has catalyzed concern about Bsal in the U.S. Surveillance programs for invading pathogens must initially meet challenges that include low rates of occurrence on the lInforming amphibian conservation efforts with abundance-based metapopulation models
Science-based management strategies are needed to halt or reverse the global decline of amphibians. In many cases, sound management requires reliable models built using monitoring data. Historically, monitoring and statistical modeling efforts have focused on estimating occupancy using detection–nondetection data. Spatial occupancy models are useful for studying colonization–extinction dynamics, bEffects of snowpack, temperature, and disease on the demography of a wild population of amphibians
Understanding the demographic consequences of interactions among pathogens, hosts, and weather conditions is critical in determining how amphibian populations respond to disease and in identifying site-specific conservation actions that can be developed to bolster persistence of amphibian populations. We investigated population dynamics in Boreal Toads (Anaxyrus boreas) relative to abiotic (fall tNon-USGS Publications**
Muths, E. 2015. Dust jacket blurb for book Salamandria by S. Trauth and J. Trauth. Mockingbird Lane Press.Muths, E. 1999. Dwarf shrew found in Rocky Mountain National Park. Park Science 19(1): 25.Muths, E., and L.A. Hinds. 1996. Circulating levels of prolactin and progesterone in a wild population of red kangaroos (Macropus rufus) Marsupialia: Macropodidae. General and Comparative Endocrinology. 101: 317-3.Muths, E., and O.J. Reichman. 1996. Kangaroo rat bone compared to white rat bone after short-term disuse and exercise. Comparative Biochemistry and Physiology. 114A(4): 355-3.Muths, E. 1996. Milk composition in a field population of red kangaroos, Macropus rufus (Desmarest) (Macropodidae: Marsupialia). Australian Journal of Zoology. 44: 165-1.
Muths, E. 1991. Substrate Discrimination in Burying Beetles, Nicrophorus orbicollis (Coleoptera: Silphidae). Journal of the Kansas Entomological Society. 64(4): 447-450.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government