Amphibians are the most threatened groups of animals on the planet. Diseases (e.g., chytrid fungi, ranavirus, severe perkinsea infections (SPI)) are negatively impacting these species. Chytrid fungus (Batrachochytrium dendrobatidis, Bd) was identified 15 years ago as one of the primary causes of death for many amphibians. However, the ecology and epidemiology of Bd is still being investigated. A second type of chytrid fungus (Batrachochytrium salamandrivorans, Bsal) is emerging in Europe. While Bsal primarily affects salamanders, frogs can also become infected and spread this disease. SPI has been associated with large-scale frog die-offs in at least 10 states.
USGS formed the Amphibian Research and Monitoring Initiative (ARMI) to lead a cooperative national effort that is monitoring amphibians and researching potential causes of decline, including disease.
Amphibian Disease Research
Report Mortality Events and Submit Specimens
Amphibian Research and Occupancy Modeling in the South-Central Region of the Amphibian Research and Monitoring Initiative (ARMI)
A is for Amphibian
Interaction of Environmental Stressors and Batrachochytrium dendrobatidis (Bd) Pathogen Loads on Survival of Green Frogs (Lithobates clamitans)
Disease
Batrachochytrium salamandrivorans (Bsal) Surveillance
Batrachochytrium salamandrivorans (Bsal)
Ecology and Conservation of Amphibians in Northern California
Amphibian Research and Monitoring Initiative: Midwest Region
Amphibian Chytrid Fungus Sampling in Arizona and Mexico
Evaluating the Prevalence of the Amphibian Chytrid Fungus, Batrachochytrium dendrobatidis, in the Southeastern U.S.: Any Evidence of Disease-Related Population Declines?
Explore our science using the data below.
Amphibian Chytrid Swab Data from Churchill County, Nevada (2019-2021)
Presence and prevalence of pathogens among amphibians of Catoctin Mountain Park, 2014
Boreal toad metamorph capture, recapture and covariates data, Colorado 2017-2018
Boreal toad survival data in relation to Bd status and community composition
Amphibian capture mark-recapture
Data from a national survey for the amphibian chytrid fungus Batrachochytrium salamandrivorans
Pathology and bacteriology of 178 tadpoles with histologically confirmed Severe Perkinsea Infections: Data
Demography and habitat use of boreal toads (Anaxyrus boreas) and other amphibians in northern Wyoming (Blackrock).
Pathogenic lineage of Perkinsea causes mass mortality of frogs across the USA: Data
Recent publications (2020-2022) related to USGS amphibian disease research are listed below. A complete listing of USGS amphibian disease publications is available from the button below.
Looking ahead, guided by the past: The role of U.S. national parks in amphibian research and conservation
Looking ahead, guided by the past: The role of U.S. national parks in amphibian research and conservation
Identifying factors linked with persistence of reintroduced populations: Lessons learned from 25 years of amphibian translocations
Site- and individual-level contaminations affect infection prevalence of an emerging infectious disease of amphibians
Low occurrence of ranavirus in the Prairie Pothole Region of Montana and North Dakota (USA) contrasts with prior surveys
Acute mortality in California tiger salamander (Ambystoma californiense) and Santa Cruz long-toed salamander (Ambystoma macrodactylum croceum) caused by Ribeiroia ondatrae (Class: Trematoda)
Evaluation of regulatory action and surveillance as preventive risk-mitigation to an emerging global amphibian pathogen Batrachochytrium salamandrivorans (Bsal)
Enigmatic near‐extirpation in a boreal toad metapopulation in northwestern Montana
Widespread Ranavirus and Perkinsea infections in Cuban treefrogs (Osteopilus septentrionalis) invading New Orleans, USA
Enhanced between-site biosecurity to minimize herpetofaunal disease-causing pathogen transmission
Batrachochytrium salamandrivorans (Bsal) not detected in an intensive survey of wild North American amphibians
Climate’s cascading effects on disease, predation, and hatching success in Anaxyrus canorus, the threatened Yosemite toad
- Overview
Amphibians are the most threatened groups of animals on the planet. Diseases (e.g., chytrid fungi, ranavirus, severe perkinsea infections (SPI)) are negatively impacting these species. Chytrid fungus (Batrachochytrium dendrobatidis, Bd) was identified 15 years ago as one of the primary causes of death for many amphibians. However, the ecology and epidemiology of Bd is still being investigated. A second type of chytrid fungus (Batrachochytrium salamandrivorans, Bsal) is emerging in Europe. While Bsal primarily affects salamanders, frogs can also become infected and spread this disease. SPI has been associated with large-scale frog die-offs in at least 10 states.
USGS formed the Amphibian Research and Monitoring Initiative (ARMI) to lead a cooperative national effort that is monitoring amphibians and researching potential causes of decline, including disease.
Amphibian Disease ResearchReport Mortality Events and Submit Specimens
Instructions for reporting wildlife morbidity/mortality and submitting specimens to the USGS National Wildlife Health Center (NWHC).Amphibian Research and Occupancy Modeling in the South-Central Region of the Amphibian Research and Monitoring Initiative (ARMI)
In response to growing public concerns about this loss of biodiversity, the U.S. Congress funded the Amphibian Research and Monitoring Initiative (ARMI), a national program coordinated by the U.S. Geological Survey.A is for Amphibian
On April 26th, 2021, Department of Interior Secretary Deb Haaland declared May 2 - 8, 2021 as Amphibain Week! This is in In recognition of the vital importance of amphibians (frogs, toads, and salamanders) to the Nation’s public and private lands. Did you know that the USGS Ecosystems Mission Area is the biological research arm of the U.S. Department of the Interior? USGS Ecosystems Mission Area...Interaction of Environmental Stressors and Batrachochytrium dendrobatidis (Bd) Pathogen Loads on Survival of Green Frogs (Lithobates clamitans)
The U.S. Geological Survey Amphibian Research Monitoring Initiative (ARMI) is using a combination of swabbing, non-lethal tissue sampling, soil and water sampling, and collection of a variety of other environmental variables to determine the relationships between the prevalence and pathogen load of Bd infection and environmental stressors on green treefrog survival.Disease
Disease is a major threat facing amphibian and reptile populations around the world. Our research addresses interactions between pathogens, the environment, and hosts to better understand ways to prevent the spread of disease.Batrachochytrium salamandrivorans (Bsal) Surveillance
Scientists of the USGS National Wildlife Health Center (NWHC) in collaboration with partners have developed risk assessments for Batrachochytrium salamandrivorans (Bsal) in the United States and have begun sampling high-risk locations for the fungus.Batrachochytrium salamandrivorans (Bsal)
Batrachochytrium salamandrivorans (Bsal) is an emerging pathogen capable of causing significant morbidity and mortality in salamanders.Ecology and Conservation of Amphibians in Northern California
This project improves our understanding of the ecology of amphibians in northern California and evaluates methods of managing landscapes and these imperiled species. In particular, Dr. Brian Halstead examines the distribution and demography of amphibians to understand factors that affect where amphibians are found and how populations change. He further explores the relationships of amphibians with...Amphibian Research and Monitoring Initiative: Midwest Region
Populations of amphibians have been declining around the world (Stokstad 2004). The US Geological Survey is working to understand the extent and causes of such declines via the Amphibian Research and Monitoring Initiative (ARMI). We are conducting research in support of this program in the Midwest Region of ARMI. Our offices and laboratories are at the Upper Midwest Environmental Sciences Center...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...Evaluating the Prevalence of the Amphibian Chytrid Fungus, Batrachochytrium dendrobatidis, in the Southeastern U.S.: Any Evidence of Disease-Related Population Declines?
Pathogens and infectious disease play a role in some recent species extinctions and are likely to impact biodiversity in the future. Environmental DNA - eDNA - is coupled with traditional amphibian sampling methods to determine the distribution and prevalence of the amphibian chytrid fungus, also known as Bd, in the southeastern US. - Data
Explore our science using the data below.
Amphibian Chytrid Swab Data from Churchill County, Nevada (2019-2021)
This dataset includes results from external skin swabbing of Anaxyrus williamsi and Lithobates catesbeianus to test for the fungus Batrachochytrium dendrobatidis from the Dixie Valley in Churchill County, Nevada, in 2019-2021.Presence and prevalence of pathogens among amphibians of Catoctin Mountain Park, 2014
Data described herein was collected by USGS personnel and the project funded by USGS and the National Park Service (Catoctin Mountain Park) through a FY14 NRPP project involving both agencies and developed to detect the presence and prevalence of ranavirus and chytrid pathogens among amphibians of Catoctin Mountain Park (CATO). Supplemental molecular analyses were performed on behalf of LSC by theBoreal 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 aBoreal toad survival data in relation to Bd status and community composition
These data represent capture mark recapture data from toads, and results of testing for Bd (Batrachochytrium dendrobatidis) the pathogen that causes amphibian chytridiomycosis on individuals. The data span from 2004-2016 at three sites in Montana where boreal toads were declining. The data also include temperature measurements at the sites and information on the egg counts and Bd prevalence from CAmphibian 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.Data from a national survey for the amphibian chytrid fungus Batrachochytrium salamandrivorans
This dataset provides the results of a national survey of the conterminous U.S. for the salamander chytrid fungus Batrachochytrium salamandrivorans (Bsal) conducted by the U.S. Geological Survey Amphibian Research and Monitoring Initiative from May 2014 to August 2017. Sites were sampled by capturing amphibians by hand or by traps or nets that were then swabbed individually using methods that prevPathology and bacteriology of 178 tadpoles with histologically confirmed Severe Perkinsea Infections: Data
(i) This dataset presents macroscopic and microscopic pathological findings and bacteriology of 178 tadpoles diagnosed with Severe Perkinsea Infections. (ii) Specimen were collected and submitted to the NWHC as part of mortality investigations and collection of specimen from apparently healthy populations as part of ongoing amphibian health monitoring. (iii) Necropsies and gross evaluation of carcDemography 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 concePathogenic lineage of Perkinsea causes mass mortality of frogs across the USA: Data
Severe perkinsea data was based on the observation of characteristic gross and microscopic lesions and the morphological identification of Perkinsea organisms within the lesions. Necropsies and gross evaluation of carcasses were carried out under a dissecting microscope. Specimen were collected and submitted to the NWHC as part of mortality investigations and collection of specimen from apparently - Publications
Recent publications (2020-2022) related to USGS amphibian disease research are listed below. A complete listing of USGS amphibian disease publications is available from the button below.
Filter Total Items: 19Looking 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 proteAuthorsBrian J. Halstead, Andrew M. Ray, Erin L. Muths, Evan H. Campbell Grant, Rob Grasso, Michael J. Adams, Kathleen Semple Delaney, Jane Carlson, Blake R. HossackLooking 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 proteAuthorsBrian J. Halstead, Andrew M. Ray, Erin L. Muths, Evan H. Campbell Grant, Rob Grasso, Michael J. Adams, Kathleen Semple Delaney, Jane Carlson, Blake R. HossackIdentifying factors linked with persistence of reintroduced populations: Lessons learned from 25 years of amphibian translocations
Conservation translocations are increasingly used to help recover imperiled species. However, success of establishing populations remains low, especially for amphibians. Identifying factors associated with translocation success can help increase efficiency and efficacy of recovery efforts. Since the 1990s, several captive and semi-captive facilities have produced Chiricahua Leopard Frogs (Rana chiAuthorsBlake R. Hossack, Paige E. Howell, Audrey K Owens, C Cobos, Caren S. Goldberg, David L. Hall, Shaula Hedwall, Susi MacVean, Magnus McCaffery, A. Hunter McCall, C Mosley, Emily Bea Oja, James C. Rorabaugh, Brent H. Sigafus, Michael J SredlSite- and individual-level contaminations affect infection prevalence of an emerging infectious disease of amphibians
Emerging infectious disease outbreaks are one of multiple stressors responsible for amphibian declines globally. In the northeastern United States, ranaviral diseases are prevalent in amphibians and other ectothermic species, but there is still uncertainty as to whether their presence is leading to population level effects. Further, there is also uncertainty surrounding the potential interactionsAuthorsKelly Smalling, Brittany A. Mosher, Luke R. Iwanowicz, Keith Loftin, Adam Boehlke, Michelle Hladik, Carly R. Muletz-Wolz, Nandadevi Córtes-Rodríguez, Robin Femmer, Evan H. Campbell GrantByEcosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, Eastern Ecological Science Center, California Water Science Center, Geology, Geophysics, and Geochemistry Science Center, Kansas Water Science Center, New Jersey Water Science CenterLow occurrence of ranavirus in the Prairie Pothole Region of Montana and North Dakota (USA) contrasts with prior surveys
Ranaviruses are emerging pathogens that have caused mortality events in amphibians worldwide. Despite the negative effects of ranaviruses on amphibian populations, monitoring efforts are still lacking in many areas, including in the Prairie Pothole Region (PPR) of North America. Some PPR wetlands in Montana and North Dakota (USA) have been contaminated by energy-related saline wastewaters, and incAuthorsBrian J. Tornabene, Erica J Crespi, Bernardo A. Traversari, Kenzi M Stemp, Creagh W Breuner, Caren S. Goldberg, Blake R. HossackAcute mortality in California tiger salamander (Ambystoma californiense) and Santa Cruz long-toed salamander (Ambystoma macrodactylum croceum) caused by Ribeiroia ondatrae (Class: Trematoda)
In early September 2019, a morbidity and mortality event affecting California tiger salamanders (Ambystoma californiense) and Santa Cruz long-toed salamanders (Ambystoma macrodactylum croceum) in late stages of metamorphosis was reported at a National Wildlife Refuge in Santa Cruz County, California, U.S.A. During the postmortem disease investigation, severe integumentary metacercarial (Class: TreAuthorsSaskia Keller, Constance Roderick, Christopher Caris, Daniel A. Grear, Rebecca A. ColeEvaluation of regulatory action and surveillance as preventive risk-mitigation to an emerging global amphibian pathogen Batrachochytrium salamandrivorans (Bsal)
The emerging amphibian pathogen Batrachochytrium salamandrivorans (Bsal) is a severe threat to global urodelan (salamanders, newts, and related taxa) biodiversity. Bsal has not been detected, to date, in North America, but the risk is high because North America is one of the global hotspots for urodelan biodiversity. The North American and United States response to the discovery of Bsal in EuropeAuthorsDaniel A. Grear, Brittany A. Mosher, Katherine Richgels, Evan H. Campbell GrantEnigmatic near‐extirpation in a boreal toad metapopulation in northwestern Montana
North America's protected lands harbor biodiversity and provide habitats where species threatened by a variety of stressors in other environments can thrive. Yet disease, climate change, and other threats are not limited by land management boundaries and can interact with conditions within protected landscapes to affect sensitive populations. We examined the population dynamics of a boreal toad (AAuthorsRebecca McCaffery, Robin E. Russell, Blake R. HossackWidespread Ranavirus and Perkinsea infections in Cuban treefrogs (Osteopilus septentrionalis) invading New Orleans, USA
Invasive species can negatively impact ecosystems in numerous ways, including vectoring pathogenic organisms. In amphibians, a lineage globally threatened by multiple pathogens, this spread of disease via invasive species could contribute to declines in native populations. The Cuban Treefrog (Osteopilus septentrionalis) is invasive in the southeastern USA. To assess whether O. septentrionalis is aAuthorsNet Galt, Matthew S Atkinson, Brad Glorioso, Hardin Waddle, Melanie Litton, Anna E. SavageEnhanced between-site biosecurity to minimize herpetofaunal disease-causing pathogen transmission
Pathogens and their associated diseases have the potential to severely affect wildlife populations, including herpetofauna. Concern is increasing for transmission pathways of herpetofaunal diseases, especially for amphibians affected by the fungal pathogens Batrachochytrium dendrobatidis (Bd: Longcore et al. 1999) and B. salamandrivorans (Bsal: Martel et al. 2013), and amphibians and reptiles affeAuthorsDeanna H. Olson, Katherine H. Haman, Matthew J. Gray, Reid N. Harris, Tracy Thompson, Marley Iredale, Michelle Christman, Jennifer M. Williams, Michael J. Adams, Jennifer R. BallardBatrachochytrium 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 lAuthorsHardin Waddle, Daniel A. Grear, Brittany Mosher, Evan H. Campbell Grant, Michael J. Adams, Adam R. Backlin, William Barichivich, Adrianne B. Brand, Gary M. Bucciarelli, Daniel L. Calhoun, Tara Chestnut, Jon M. Davenport, Andrew E. Dietrich, Robert N. Fisher, Brad Glorioso, Brian J. Halstead, Marc P Hayes, R. Ken Honeycutt, Blake R. Hossack, Patrick M. Kleeman, Julio A. Lemos-Espinal, Jeffrey M. Lorch, Robert W. Atkinson, Erin L. Muths, Christopher Pearl, Katherine Richgels, Charles W Robinson, Mark F. Roth, Jennifer Rowe, Walter Sadinski, Brent H. Sigafus, Iga Stasiak, Samuel Sweet, Susan C. Walls, Gregory J Watkins-Colwell, C. LeAnn White, Lori A Williams, Megan E. WinzelerClimate’s cascading effects on disease, predation, and hatching success in Anaxyrus canorus, the threatened Yosemite toad
The U.S. Fish and Wildlife Service listed Anaxyrus canorus, the Yosemite toad, as federally threatened in 2014 based upon reported population declines and vulnerability to global-change factors. A. canorus lives only in California’s central Sierra Nevada at medium to sub-alpine elevations. Lands throughout its range are protected from development, but climate and other global-change factors potentAuthorsWalter Sadinski, Alisa L. Gallant, James E. Cleaver