Endangered

IUCN species status

Also known as: EN

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July 21, 2026

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An endangered species is any species at risk of extinction due to a rapid population decrease or loss of critical habitat. The International Union for Conservation of Nature (IUCN) maintains the Red List of Threatened Species, a comprehensive global assessment system.1

The IUCN uses five criteria to classify species' extinction risk, including population decline rate, geographic range, population size, and quantitative analysis of extinction probability. A species is classified as endangered if it faces a very high risk of extinction, characterized by a 50-70% population decline over 10 years, fewer than 250 individuals, or a projected extinction within 20 years.23

Human activities are the primary drivers of species endangerment, including habitat loss and degradation, invasive species, global warming, pollution, and

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endangered species
IUCN Red List of Threatened Species
…generation times, or isolated habitats) Endangered (EN), species that possess a very high risk of extinction as a result of rapid population declines of 50 to more than 70 percent over the previous 10 years (or three generations), a current population size of fewer than 250 individuals, or other factors…
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…generation times, or isolated habitats) Endangered (EN), species that possess a very high risk of extinction as a result of rapid population declines of 50 to more than 70 percent over the previous 10 years (or three generations), a current population size of fewer than 250 individuals, or other factors…
Read More