In the 2012 President's Budget Request, the National Biological Information Infrastructure (NBII) is terminated. As a result, all resources, databases, tools, and applications within this web site will be removed on January 15, 2012. For more information, please refer to the NBII Program Termination page.
Can't see Flash? Install <a href="http://www.adobe.com/shockwave/download/download.cgi?P1_Prod_Version=ShockwaveFlash" _djrealurl="http://www.adobe.com/shockwave/download/download.cgi?P1_Prod_Version=ShockwaveFlash" target="_blank">Flash Player</span></a> or <a href="http://www.nwhc.usgs.gov/publications/fact_sheets/pdfs/frog.pdf" _djrealurl="http://www.nwhc.usgs.gov/publications/fact_sheets/pdfs/frog.pdf" target="_blank">access the content from U.S. Geological Survey, National Wildlife Health Center</a>.
<p align="center"><a title="http://www.nwhc.usgs.gov/publications/fact_sheets/pdfs/frog.pdf" href="http://www.nwhc.usgs.gov/publications/fact_sheets/pdfs/frog.pdf" _djrealurl="http://www.nwhc.usgs.gov/publications/fact_sheets/pdfs/frog.pdf" target="_blank"></a><img alt="Thumbnail image of Field Guide to Amphibian Malformations" src="http://www.nbii.gov/portal/server.pt/gateway/PTARGS_0_737_14199_386_5146_43/http%3B/cbi-lap7.cbi.cr.usgs.gov%3B7097/publishedcontent/publish/plants___animals/highlight_amphibians_malformations_field_guide/guide.gif" _djrealurl="http://www.nbii.gov/portal/server.pt/gateway/PTARGS_0_737_14199_386_5146_43/http%3B/cbi-lap7.cbi.cr.usgs.gov%3B7097/publishedcontent/publish/plants___animals/highlight_amphibians_malformations_field_guide/guide.gif"> <br><span class="imgCredit">[Photo: U.S. Geological Survey] </span></p>
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)
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
Reports surfaced from other areas of the nation that frogs with similar malformations were present.
In the past decade, extensive research into the
has been undertaken by scientists from government, academic, and non-profit sectors. Scientists have identified several
variables potentially contributing to malformations,
ultraviolet radiation, contaminants,
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.
Founded and developed by the U.S. Geological Survey's Northern Prairie Wildlife Research Center, NARCAM is now managed by the Southeast Information Node of the U.S. Geological Survey's National Biological Information Infrastructure (NBII) in partnership with the University of Georgia's Savannah River Ecology Lab.
Amphibian Malformations: What Are the Causes?
multiple causes are likely to blame for worldwide reports of amphibian malformations,
and factors leading to malformations at one site may differ from causes at another site. At this time,
three major environmental factors identified as the causes of malformations include:
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, and missing eyes.
U.S. Fish and Wildlife Service Abnormal Amphibian Surveys
[Photo: Laura Eaton-Poole, U.S. Fish & Wildlife Service]