U.S. Fish and Wildlife Service Abnormal Amphibian Surveys

Northern leopard frog (Rana pipiens) with polymelia (extra limb).
[Photo: Laura Eaton-Poole, U.S. Fish & Wildlife Service]

The U.S. Fish and Wildlife Service's Division of Environmental Quality is actively involved in studying amphibian declines and abnormalities. To better study amphibians and the concerns facing them, the Fish and Wildlife Service has developed standard operating procedures (SOPs) for abnormal amphibian surveys on U.S. Fish and Wildlife Service wildlife refuges. The Fish and Wildlife Service's Amphibian Declines and Deformities Web page provides more information about how the U.S. Fish and Wildlife Service works to conserve threatened and endangered amphibians.

Amphibian Declines

Amphibian populations are in decline in many areas of the world. In cities and in natural areas, in rainforests and in wetlands, countless areas which previously hosted a range of healthy amphibian populations now have fewer - or even no - frogs, toads, and salamanders. Although healthy populations of some species may exist elsewhere, in some cases, a few species - including Costa Rica's Monteverde golden toad and Australia's Gastric brooding frog - are now believed extinct.

What is causing these mysterious declines? Scientists conducting field research have produced compelling evidence that habitat loss, disease, climatic change, UV radiation, contaminants and pollutants, and predation by invasive species contribute to amphibian declines. Probably most baffling, amphibian declines are not always occurring in "likely" places where human impacts are obvious, such as cities and suburbs prone to development and pollution; indeed, some of the most noted and dramatic declines are happening in "protected" areas such as national parks.

The scientific community now suspects that there is no single reason for worldwide declines of amphibians. For example, diseases or pollutants that have decimated a species in one part of the world may be absent in another region that has also experienced amphibian die-offs. In some cases, die-offs can be attributed to a specific cause; in other cases, the cause is not so obvious. Many researchers believe that multiple, additive causes - for instance, habitat loss and the introduction of disease - may be at the heart of large numbers of worldwide declines.

As research on amphibian declines continues, new findings will be published to the Web.  To find these and other online resources, search for information on amphibian declines by browsing topic areas from the navigation menu at left.

Amphibian Research & Monitoring Initiative (ARMI)

ARMI logo
[Image: USGS]

The national Amphibian Research and Monitoring Initiative (ARMI) is a multi-sector effort, coordinated by the U.S. Geological Survey, to monitor amphibians on public lands across the nation.

ARMI is establishing national metrics, standards, and protocols to help researchers better "compare" populations, and to address variables across monitoring sites. Comparisons of broad-scale patterns of amphibian distributions with current and historic patterns of environmental characteristics are underway to facilitate the development of hypotheses about influences on amphibian distributions and support efforts toward amphibian conservation.

One valuable product from ARMI that is useful to both the research community and the public is the ARMI National Atlas for Amphibian Distributions, a browsable tool that allows users to visualize distributions at the state and county level for most of the amphibian species occurring in the U.S.

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