About the GAA
Project Overview
Partners
Methods
   Data Collection
   Data Review
   Data Consolidation
   Data Analysis
Future Steps
Use and Citation

Project Overview

The Global Amphibian Assessment (GAA) is the comprehensive status assessment of the world's 5,918 known amphibian species, against the IUCN Red List Categories and Criteria, and as such is an important contribution to the Red List Programme. Almost 600 scientists from 60 countries have now contributed to the project. Since the first release in 2004, the data has been continually upgraded and revised, and this newly updated information is now published in the 2006 IUCN Red List of Threatened Species as well as here on the Global Amphibian Assessment website.

• To determine the scale (both the magnitude of threat and the geographic focus) of the current extinction crisis in amphibians.
• To identify the most important geographic areas and habitats that need to be conserved to avoid further species extinctions.
• To identify the major threats and to propose mitigating measures and prioritized conservation actions to address them.
• To establish an expert network focused on amphibians so that the Global Amphibian Assessment can be kept current, and expertise can be targeted to address the highest conservation priorities.

Marbled salamander (Ambystoma opacum ), United States / Photo by Don Church	Hyperolius rubrovermiculatus (an African reed frog), Kenya / Photo by de Saix	Uraeotyphlus sp. (a caecilian), India / Photo by John Measey

Amphibians are a class of vertebrates that include frogs, toads, salamanders, newts and caecilians. All amphibians are cold-blooded, and most lay eggs. The majority of species undergo metamorphosis, moving from a larval stage (usually aquatic) through the development of limbs and lungs to become terrestrial adults. However, a significant minority of the species develop directly from eggs, usually laid on land, without a larval stage. There are also a few viviparous species that give birth to young, without laying eggs.

Almost all species are dependent on moist conditions, and many require freshwater habitats in which to breed. The greatest diversity occurs in tropical forests, with species richness generally lower in temperate and arid regions. Amphibians are entirely absent from marine environments.

Amphibians are excellent indicators of the quality of the overall environment, as they are very sensitive to perturbations in ecosystems. Additional general information about amphibians can be found on AmphibiaWeb.