Endangered Species Critical Habitats

Alliance for Zero Extinction sites are Key Biodiversity Areas containing 95% or more of the remaining population of one or more species listed as Endangered or Critically Endangered on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species.

  • Source: AZE


The dataset represents the boundaries of sites containing 95% or more of the remaining population of one or more species listed as Endangered or Critically Endangered on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species.

The Alliance for Zero Extinction (AZE) originally created this dataset with a goal to prevent extinctions by identifying and safeguarding key sites. The 2019 March version of this dataset contains 859 sites, supporting 1483 Critically Endangered or Endangered species.

AZE sites are Key Biodiversity Areas (KBAs ‘sites contributing significantly to the global persistence of biodiversity’) that qualify under criterion A1e. Data on AZEs and other KBAs are managed in the World Database on Key Biodiversity Areas.


All confirmed AZE sites qualify as KBAs under KBA criterion A1e because they “regularly hold effectively the entire global population size of a “Critically Endangered” or “Endangered” species.” AZE sites are those KBAs in most urgent need of conservation in order to prevent imminent global extinction.

There are three criteria to identify AZE sites:

  1. Endangerment: Must contain at least one Endangered or Critically Endangered species, as listed on the IUCN Red List of Threatened Species. A site cannot be designated on the basis of unlisted or unevaluated species, Data Deficient species, or Vulnerable species. A site may be designated as the only suitable reintroduction site for a species assessed as Extinct in the Wild.
  2. Irreplaceability: Must a) be the sole area where an Endangered or Critically Endangered species occurs, b) contain the overwhelmingly significant known resident population the species (more than 95% of the global population), or c) contain the overwhelmingly significant known population for one life-history segment (e.g., breeding or non-breeding) of the species.
  3. Discreteness: Must have a definable boundary, within which habitats, biological communities, or management issues share more in common with each other than they do with those in adjacent areas (e.g., a single lake, mountaintop, or forest fragment). The boundary of each area is based on the most practical conservation unit, including considerations of contiguous habitat, management units, and the potential for significant gene flow among populations.

Visit KBA website and learn about how KBAs are identified.

For the full documentation, please click on the “Learn more” button.

Data shown on Resource Watch Map


Excerpts of this description page were taken from the source metadata. Resource Watch shows only a subset of the dataset. For access to the full dataset and additional information, click on the “Learn more” button.

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Formal name

Alliance for Zero Extinction (AZE) Sites


Represents sites for the following taxonomic groups only: amphibians, birds, cacti, cone snails, conifers, corals, cycads, freshwater crabs, freshwater crayfish, freshwater shrimps, mammals, mangrove plants, selected marine fish (blennies, groupers, pufferfish, wrasses), selected reptiles (chameleons, crocodiles, iguanas, tortoises, turtles), sharks and rays, and selected birches.

Suggested citation

BirdLife International (2019) Alliance for Zero Extinction digital boundaries. March 2019 Version. Derived from the World Database of Key Biodiversity Areas. Developed by the KBA Partnership (BirdLife International, International Union for the Conservation of Nature, American Bird Conservancy, Amphibian Survival Alliance, Conservation International, Critical Ecosystem Partnership Fund, Global Environment Facility, Global Wildlife Conservation, NatureServe, Royal Society for the Conservation of Birds, Wildlife Conservation Society and World Wildlife Fund). Available at www.keybiodiversityareas.org. Accessed through Resource Watch, (date). www.resourcewatch.org.


Alliance for Zero Extinctions (AZE)

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