The first Global Amphibian Assessment (GAA) was a 2001–2004 joint initiative led by IUCN, Conservation International and NatureServe, which conducted the first comprehensive assessment of all known amphibian species for the IUCN Red List. Amphibian data on the IUCN Red List were subsequently updated in 2006 and 2008.
The results were staggering: the GAA demonstrated that amphibians around the world are significantly more threatened than other vertebrate groups, namely birds and mammals. This and other key findings of the GAA are outlined in Stuart et al. 2004. The GAA methods and contributors can be found in the article’s supporting documentation.
A summary of the GAA, as well as, the 2008 IUCN Red List data can be downloaded here.
The seminal book, Threatened Amphibians of the World (2008), includes an in-depth analysis of the 2006 updated IUCN Red List data and is available for download.