How similar are national red lists and the IUCN Red List?

For more than four decades the International Union for the Conservation of Nature (IUCN) has been assessing the global threat status for species and publishing the results in the periodically updated IUCN Red List of threatened species. Additionally, numerous countries have published national lists of threatened species, often based on IUCN criteria and guidelines for application of IUCN Red List criteria at regional levels. To assess how similar, or how different, national red lists are from the global red list, we compared threatened species lists of four countries (Brazil, Colombia, China, and the Philippines) with the 2008 IUCN Red List. We found notable differences falling into three categories: (1) a number of species (an average of 20% of the species pool considered in each of the four countries) have been listed nationally as threatened, but have yet to be globally assessed by IUCN, (2) some species (14% average) are considered globally threatened by IUCN, but are not listed nationally, and (3) a handful of species (2% average) are not considered threatened by IUCN, but are nationally threatened. However, for most species, the threat assessments concur. In other words, most species are either considered threatened both nationally and globally, or else not considered globally threatened and not listed nationally. Such possible comparison between national red lists and IUCN’s Red List is a high priority both for IUCN and for national red listing agencies.