Scientific data on endangered species and threatened ecosystems provided by an international network of conservation data centers operating in all 50 U.S. states, Canada, Latin America and the Caribbean. http://www.natureserve.org
The International Union for Conservation of Nature has for more than four decades been assessing the conservation status of species on a global scale in order to highlight taxa threatened with extinction, and therefore promote their conservation. http://www.iucnredlist.org