Threatened species are populations of living organisms at risk of extinction across all groups of life. The term applies broadly to any species, including wild animals, plants, and many kinds of fungi. It is a descriptive label used by conservationists, scientists and policy makers to flag species whose numbers, distribution or trends indicate they may soon disappear from the wild unless conditions change.

How risk is assessed

Assessments of extinction risk combine information about population size and trends, geographic range, reproductive rates, and threats such as habitat loss or exploitation. Professional bodies synthesize these data into standardized evaluations. The most widely used global framework is the system maintained by the International Union for Conservation of Nature (IUCN), which provides objective criteria to judge how close a species is to extinction and to document uncertainty where information is lacking.

Principal categories

  • Vulnerable — species facing a high risk of extinction in the medium term.
  • Endangered — species at very high risk of extinction in the near future.
  • Critically Endangered — species facing an extremely high risk of imminent extinction in the wild.

Those categories form the core of what people commonly call "threatened species." Complementary terms are used for species with lower concern (for example, "near threatened" or "least concern") or where information is insufficient to judge status.

Main drivers of decline

Multiple human-caused and natural factors contribute to species becoming threatened. Habitat destruction and fragmentation, overexploitation (such as overfishing or intensive hunting), pollution, invasive species, and disease are frequent causes. Climate change is an increasing driver, altering habitats and interactions in ways that can push already vulnerable species toward extinction. Small or isolated populations are also more likely to fall into demographic trouble through reduced reproduction and genetic diversity.

Conservation responses and importance

Actions to reduce extinction risk range from habitat protection and restoration, legal safeguards, captive breeding and reintroduction programs, to targeted measures such as controlling invasive species or modifying fisheries. Effective conservation combines scientific assessment, local and national policy, and often international cooperation. Protecting threatened species preserves ecological functions, cultural values, and genetic diversity important for resilient ecosystems and human well‑being.

Notable distinctions and resources

Two points often cause confusion: first, being listed as threatened does not always mean a species is declining everywhere—some populations may be stable while others are in trouble. Second, assessment outcomes depend on available data; species labeled as "data deficient" require further study before their true risk is known. For more detailed information, including species accounts and technical criteria, consult the global registry maintained by experts and summarized in the IUCN Red List.