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.
The Science Issue and Relevance: Declines in the abundance and increases in extinction and extirpation of amphibian species have been observed in habitats around the world since at least 1989. Several hypotheses have been proposed to explain this trend. Widespread disease, climate change, and the interaction of the two are perhaps the leading hypotheses for “mysterious” declines of amphibians in relatively undisturbed protected areas. In agricultural and suburban landscapes, environmental contaminants and habitat loss or degradation are the leading factors in amphibian decline. 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. The overall goal of this program is to monitor trends in amphibian populations on Department of the Interior (DOI) lands, and to study the causes of any detected declines in amphibian populations.
Methodology for Addressing the Issue: Time-constrained visual encounter surveys are used to sample amphibian populations. Sites are chosen randomly within each study stratum (management unit) in a manner such that any point has an equal likelihood of being chosen. A team of two or more observers visits each randomly chosen point no earlier than 30 minutes after sunset. The observers search a 20-meter radius circle around the point using powerful headlamps. All individual anurans (frogs and toads) observed are captured if possible, identified to species, and measured to obtain snout-vent length. In addition, all anuran species detected vocalizing are noted. Environmental data including air temperature, relative humidity, wind speed, water temperature, water depth, and time and date are also collected at each site. Between 30-70 sites are sampled per stratum, and each site is sampled on at least four separate occasions. Anuran data are analyzed in the site occupancy framework, which produces an estimate of the proportion of area occupied for each species given imperfect detection of the species using sampling covariates. Models may be fit using maximum likelihood methods or under a Bayesian inferential method using Markov-chain Monte Carlo simulation.
Future Steps: Monitoring for site-occupancy of amphibians was suspended after the 2016 season at our long-term sites in the Atchafalaya Basin. However, ongoing monitoring efforts and research will continue related to threats to regional amphibians. Particular attention will be paid to federally threatened and endangered species. We will also continue efforts to use amphibian populations as indicators of ecosystem condition and restoration success.
Below are other science projects associated with this project.
Interaction of Environmental Stressors and Batrachochytrium dendrobatidis (Bd) Pathogen Loads on Survival of Green Frogs (Lithobates clamitans)
Below are publications associated with this project.
A new parameterization for estimating co‐occurrence of interacting species
Identifying management-relevant research priorities for responding to disease-associated amphibian declines
Identifying management-relevant research priorities for responding to disease-associated amphibian declines
Quantifying climate sensitivity and climate-driven change in North American amphibian communities
Quantifying climate sensitivity and climate-driven change in North American amphibian communities
A new framework for analysing automated acoustic species detection data: Occupancy estimation and optimization of recordings post-processing
Quantitative evidence for the effects of multiple drivers on continental-scale amphibian declines
Reproductive biology of Ambystoma salamanders in the southeastern United States
A review of pipe and bamboo artificial refugia as sampling tools in anuran studies
Anuran site occupancy and species richness as tools for evaluating restoration of a hydrologically-modified landscape
Wetland Reserve Program enhances site occupancy and species richness in assemblages of anuran amphibians in the Mississippi Alluvial Valley, USA
Trends in amphibian occupancy in the United States
- Overview
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.
The Science Issue and Relevance: Declines in the abundance and increases in extinction and extirpation of amphibian species have been observed in habitats around the world since at least 1989. Several hypotheses have been proposed to explain this trend. Widespread disease, climate change, and the interaction of the two are perhaps the leading hypotheses for “mysterious” declines of amphibians in relatively undisturbed protected areas. In agricultural and suburban landscapes, environmental contaminants and habitat loss or degradation are the leading factors in amphibian decline. 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. The overall goal of this program is to monitor trends in amphibian populations on Department of the Interior (DOI) lands, and to study the causes of any detected declines in amphibian populations.
Cajun chorus frog (Photo by Brad M. Glorioso) Methodology for Addressing the Issue: Time-constrained visual encounter surveys are used to sample amphibian populations. Sites are chosen randomly within each study stratum (management unit) in a manner such that any point has an equal likelihood of being chosen. A team of two or more observers visits each randomly chosen point no earlier than 30 minutes after sunset. The observers search a 20-meter radius circle around the point using powerful headlamps. All individual anurans (frogs and toads) observed are captured if possible, identified to species, and measured to obtain snout-vent length. In addition, all anuran species detected vocalizing are noted. Environmental data including air temperature, relative humidity, wind speed, water temperature, water depth, and time and date are also collected at each site. Between 30-70 sites are sampled per stratum, and each site is sampled on at least four separate occasions. Anuran data are analyzed in the site occupancy framework, which produces an estimate of the proportion of area occupied for each species given imperfect detection of the species using sampling covariates. Models may be fit using maximum likelihood methods or under a Bayesian inferential method using Markov-chain Monte Carlo simulation.
Blanchard’s cricket frog (Photo by Brad M. Glorioso) Future Steps: Monitoring for site-occupancy of amphibians was suspended after the 2016 season at our long-term sites in the Atchafalaya Basin. However, ongoing monitoring efforts and research will continue related to threats to regional amphibians. Particular attention will be paid to federally threatened and endangered species. We will also continue efforts to use amphibian populations as indicators of ecosystem condition and restoration success.
- Science
Below are other science projects associated with this project.
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. - Publications
Below are publications associated with this project.
Filter Total Items: 16A new parameterization for estimating co‐occurrence of interacting species
Models currently used to estimate patterns of species co‐occurrence while accounting for errors in detection of species can be difficult to fit when the effects of covariates on species occurrence probabilities are included. The source of the estimation problems is the particular parameterization used to specify species co‐occurrence probability. We develop a new parameterization for estimating paIdentifying management-relevant research priorities for responding to disease-associated amphibian declines
A research priority can be defined as a knowledge gap that, if resolved, identifies the optimal course of conservation action. We (a group of geographically distributed and multidisciplinary research scientists) used tools from nominal group theory and decision analysis to collaboratively identify and prioritize information needs within the context of disease-associated amphibian decline, in orderByEcosystems, Water Resources, Fish & Wildlife Disease, Wildlife Program, Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, National Wildlife Health Center, New Jersey Water Science Center, Northern Rocky Mountain Science Center, Patuxent Wildlife Research Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research CenterIdentifying management-relevant research priorities for responding to disease-associated amphibian declines
A research priority can be defined as a knowledge gap that, if resolved, identifies the optimal course of conservation action. We (a group of geographically distributed and multidisciplinary research scientists) used tools from nominal group theory and decision analysis to collaboratively identify and prioritize information needs within the context of disease-associated amphibian decline, in orderByEcosystems, Water Resources, Fish & Wildlife Disease, Wildlife Program, Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, National Wildlife Health Center, New Jersey Water Science Center, Northern Rocky Mountain Science Center, Patuxent Wildlife Research Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research CenterQuantifying climate sensitivity and climate-driven change in North American amphibian communities
Changing climate will impact species’ ranges only when environmental variability directly impacts the demography of local populations. However, measurement of demographic responses to climate change has largely been limited to single species and locations. Here we show that amphibian communities are responsive to climatic variability, using >500,000 time-series observations for 81 species across 8ByEcosystems, Water Resources, Wildlife Program, Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, Northern Rocky Mountain Science Center, Patuxent Wildlife Research Center, South Atlantic Water Science Center (SAWSC), Southwest Biological Science Center, Upper Midwest Environmental Sciences Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research Center , John Wesley Powell Center for Analysis and SynthesisQuantifying climate sensitivity and climate-driven change in North American amphibian communities
Changing climate will impact species’ ranges only when environmental variability directly impacts the demography of local populations. However, measurement of demographic responses to climate change has largely been limited to single species and locations. Here we show that amphibian communities are responsive to climatic variability, using >500,000 time-series observations for 81 species across 8ByEcosystems, Water Resources, Wildlife Program, Eastern Ecological Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, Northern Rocky Mountain Science Center, Patuxent Wildlife Research Center, South Atlantic Water Science Center (SAWSC), Southwest Biological Science Center, Upper Midwest Environmental Sciences Center, Western Ecological Research Center (WERC), Wetland and Aquatic Research Center , John Wesley Powell Center for Analysis and SynthesisA new framework for analysing automated acoustic species detection data: Occupancy estimation and optimization of recordings post-processing
The development and use of automated species-detection technologies, such as acoustic recorders, for monitoring wildlife are rapidly expanding. Automated classification algorithms provide a cost- and time-effective means to process information-rich data, but often at the cost of additional detection errors. Appropriate methods are necessary to analyse such data while dealing with the different typQuantitative evidence for the effects of multiple drivers on continental-scale amphibian declines
Since amphibian declines were first proposed as a global phenomenon over a quarter century ago, the conservation community has made little progress in halting or reversing these trends. The early search for a “smoking gun” was replaced with the expectation that declines are caused by multiple drivers. While field observations and experiments have identified factors leading to increased local extinReproductive biology of Ambystoma salamanders in the southeastern United States
Reproductive aspects of Ambystoma salamanders were investigated at sites in Louisiana (2010–12) and Mississippi (2013). Three species occurred at the Louisiana site, Spotted Salamander (A. maculatum), Marbled Salamander (A. opacum), and Mole Salamander (A. talpoideum), whereas only Spotted Salamanders were studied at the Mississippi site. A total of 162 and 71 egg masses of Spotted Salamanders werA review of pipe and bamboo artificial refugia as sampling tools in anuran studies
Artificial pipe-like refugia have been used for more than 40 years in anuran studies, and have captured 28 species, primarily (82%) hylid treefrogs. Early pipe-like refugia were made using cut pieces of bamboo in the tropical forests of Puerto Rico, but most recent studies have used synthetic pipes and have occurred primarily in the southeastern United States. Characteristics of artificial refugiaAnuran site occupancy and species richness as tools for evaluating restoration of a hydrologically-modified landscape
A fundamental goal of wetland restoration is to reinstate pre-disturbance hydrological conditions to degraded landscapes, facilitating recolonization by native species and the production of resilient, functional ecosystems. To evaluate restoration success, baseline conditions need to be determined and a reference target needs to be established that will serve as an ecological blueprint in the restWetland Reserve Program enhances site occupancy and species richness in assemblages of anuran amphibians in the Mississippi Alluvial Valley, USA
We measured amphibian habitat use to quantify the effectiveness of conservation practices implemented under the Wetland Reserve Program (WRP), an initiative of the U.S. Department of Agriculture’s Natural Resources Conservation Service. From February to June 2007, we quantified calling male anurans in cultivated cropland, former cultivated cropland restored through the WRP, and mature bottomland hTrends 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 United States. We found that overall occupancy by amphi