The USGS field guide provides photographs and x-rays of the major types of malformations commonly encountered among recently metamorphosed frogs in the United States.
The field guide distinguishes between malformations caused by predation and those caused by other factors and may be used as an aid in reporting amphibian malformations.
North American Reporting Center for Amphibian Malformations (NARCAM) Report Local Amphibian Malformations
In 1996, a group of Minnesota school children on a field trip to a local pond made a disturbing discovery: dozens of frogs with missing limbs and eyes, extra limbs and underformed limbs. Reports surfaced from other areas of the nation that frogs with similar malformations were present.
In the past decade, extensive research into the malformations phenomena has been undertaken by scientists from government, academic, and non-profit sectors. Scientists have identified several variables potentially contributing to malformations, such as diseases, ultraviolet radiation, contaminants, and predation. It is probable that malformations are not the result of a single cause, but are rather brought on by different factors in different regions. The debate over malformations phenomena is far from conclusive, however, and research continues.
In cooperation with the greater scientific community, this Web site serves as a resource for people to learn about amphibian malformations phenomena in North America and for citizens to report on the health of local amphibian populations.
If you have observed malformed amphibians, we encourage you to report your sightings to the North American Reporting Center for Amphibian Malformations (NARCAM) using this site's online reporting form. You can also get information on the extent of malformation reports received to date, including geographic distribution, information on the types of malformations found and species affected in each area.
According to the U.S. Geological Survey's National Wildlife Health Center, malformations in amphibians arise from environmental factors that affect individuals at the larval stage of development. Observed malformations have included:
Missing forelimbs or hindlimbs
Extra forelimbs or hindlimbs
Incompletely formed forelimbs or hindlimbs
Missing eye(s)
Researchers suggest that multiple causes are probably to blame for the malformation instances that have been reported worldwide, and that factors leading to malformations at a particular site may be different from those causing malformations at another site. At this time, the four major environmental factors identified as the causes of malformations are contaminants, nutritional deficiencies, parasites, and injuries from predators (USGS National Wildlife Health Center).
U.S. Fish and Wildlife Service Abnormal Amphibian Surveys
NARCAM encourages the public to report observations of amphibian malformations in their local area. Citizens can submit an online report, which is reviewed and verified by a team of professional herpetologists at the University of Georgia's Savannah River Ecology Lab; once these experts verify the report, it is available to the public and to the research community for review. (Reporters of the data are made anonymous to the public).
In the near future, NARCAM will also geospatially reference this data, and provide map interfaces to assist users in accessing and viewing the data.
Savannah River Ecology Lab
The Herpetology Program of the University of Georgia Savannah River Ecology Lab, under the leadership of Dr. Whit Gibbons, provides herpetological expertise and quality assurance/quality control for all malformations reports submitted to NARCAM. All reports are reviewed for completeness, accuracy, and integrity before they are made available for public access and review.
The NBII Program is administered by the Biological Informatics Office of the U.S. Geological Survey