Targets for “Extinctions Avoided” outcomes are those species facing the highest risk of extinction; these species are listed as threatened on the IUCN Red List. The identification of Key Biodiversity Areas as targets for “Areas Protected” outcomes builds from this, and requires the careful evaluation of sites that are actually or potentially managed for conservation against a set of standard criteria driven by the species occurring within them. An important characteristic of the process of defining key biodiversity areas is that it is a locally led process and is, therefore, a “bottom-up” process organizationally as well as ecologically. To date, processes for identifying Key Biodiversity Areas have been initiated in more than half the hotspots.
A small, but extremely important, subset of key biodiversity areas are those that hold highly threatened species as endemics to a single site. To tackle these extraordinarily high priorities for site conservation, a number of organizations formed an Alliance for Zero Extinction (AZE)
in 2003. AZE aims to identify and conserve all sites holding the entire global population of one or more Critically Endangered or Endangered species. Of those AZE sites that have been identified worldwide to date, a very high proportion—nearly 80 percent— fall within the hotspots.
While the achievement of species- and site-scale conservation outcomes is essential if conservation is to succeed, it is not sufficient. A large body of ecological literature demonstrates that conservation action is also necessary at the landscape scale, for the purposes of maintaining ecological and evolutionary processes on which species and sites depend. To this end, CI defines targets for landscape scale conservation action by identifying those area-demanding threatened species that cannot be conserved at the site scale alone (due to the need for large territories, migration routes, etc.), and those ecological processes on which the persistence of Key Biodiversity Areas depends. These represent targets for “Corridors Consolidated” conservation outcomes, the achievement of which are vital for biodiversity to persist in the long-term.