The IUCN Red List Index (RLI) measures overall trends in extinction risk for sets of species, based on genuine changes in their status (their Red List category) over time. To create an index, a species or group of species must have been assessed at least twice over a period of time, using the same criteria. Few Red List indices have been created at a national or regional scale to date, but they are important in identifying trends in biodiversity and key tools for assessing the impact of national-scale conservation interventions to reverse biodiversity loss.
The IUCN Red List’s Categories and Criteria page holds guidelines for the regional and national use of the Red List Index, as well as providing calculation tools to assist in the production of an Index. We will endeavour to list all national or regional Red List Indices in our Library, as and when they are published.
Using Birds to Track Progress
There are a number of different examples of National Red List Index’s (NRLI). The following figure shows trends in the status of bird species, for a full report on the use of birds to track extinction risks, please see http://www.birdlife.org/