For a species to be considered endangered by the IUCN it must meet certain quantitative criteria which are designed to classify taxa facing "a very high risk of extinction". An even higher risk is faced by critically endangered species, which meet the quantitative criteria for endangered species. Critically endangered birds are listed separately. There are 683 avian species which are endangered or critically endangered.
Additionally 53 avian species (0.48% of those evaluated) are listed as data deficient, meaning there is insufficient information for a full assessment of conservation status. As these species typically have small distributions and/or populations, they are intrinsically likely to be threatened, according to the IUCN.[2] While the category of data deficient indicates that no assessment of extinction risk has been made for the taxa, the IUCN notes that it may be appropriate to give them "the same degree of attention as threatened taxa, at least until their status can be assessed".[3]
This is a complete list of endangered avian species evaluated by the IUCN. Where possible, common names for taxa are given while links point to the scientific name used by the IUCN.
^"IUCN Red List version 2020-3". The IUCN Red List of Threatened Species. International Union for Conservation of Nature and Natural Resources (IUCN). Archived from the original on 27 June 2014. Retrieved 10 December 2019.
^"Limitations of the Data". The IUCN Red List of Threatened Species. Union for Conservation of Nature and Natural Resources (IUCN). Archived from the original on 7 October 2018. Retrieved 11 January 2016.
^"2001 Categories & Criteria (version 3.1)". The IUCN Red List of Threatened Species. Union for Conservation of Nature and Natural Resources (IUCN). Archived from the original on 8 October 2008. Retrieved 11 January 2016.
