IUCN Red List of Threatened Species

The IUCN Red List of Threatened Species™ is the world's most comprehensive inventory of the global conservation status of plant and animal species. It uses a set of quantitative criteria to evaluate the extinction risk of thousands of species. These criteria are relevant to most species and all regions of the world. With its strong scientific base, the IUCN Red List is recognised as the most authoritative guide to the status of biological diversity.


At a glance

IUCN Red List, a global authority Photo: Angadachappa / CC4.0 The IUCN Red List of Threatened Species TM is a critical indicator Photo: Frank Vaseen / CC2.0 IUCN Photo: IUCN IUCN Photo: IUCN


species assessed

35,000 +
threatened species

160,000 species to assess – the current target 


The IUCN Red List in a nutshell

The IUCN Red List Categories

Endangered category - Red List of Threatened Species TM Photo: The IUCN Red List of Threatened Species™

The IUCN Red List Categories define the extinction risk of species assessed. Nine categories extend from NE (Not Evaluated) to EX (Extinct).

What does IUCN mean by "threatened" ?

Critically Endangered (CR), Endangered (EN) and Vulnerable (VU) species are considered to be threatened with global extinction.

What does each category mean ?

In descending order of threat, the IUCN Red List threat categories are as follows:

  • Extinct or Extinct in the Wild
  • Critically Endangered, Endangered and Vulnerable: species threatened with global extinction.
  • Near Threatened: species close to the threatened thresholds or that would be threatened without ongoing conservation measures.
  • Least Concern: species evaluated with a lower risk of extinction.
  • Data Deficient: no assessment because of insufficient data.

On top of these official categories, Critically Endangered (Possibly Extinct) is sometimes used as well. This is not a new IUCN Red List Category, but is a flag developed to identify those Critically Endangered species that are in all probability already extinct but for which confirmation is required; for example, through more extensive surveys being carried out and failing to find any individuals.

  Read more about the science behind the categories 


A global authority

The IUCN Red List assesses the conservation status of species at a global level, drawing on expert knowledge from around the world.

Who uses the Red List?

The IUCN Red List is used by institutional, business and community users such as:

  • national and international government agencies
  • wildlife departments
  • conservation-related non-governmental organisations (NGOs)
  • natural resource planners
  • educational organisations
  • zoos and aquariums
  • students
  • media
  • the business community 

How is the Red List used ?

IUCN Red List data are used for a variety of purposes:

  • International agreements use IUCN Red List data to guide decision making and as an indicator of the status of nature. These include, but are not limited to agreements such as CITES, the Ramsar Convention, UN Sustainable Development Goals and CBD Aichi Targets
  • World Bank Group Performance Standard PS6 uses The IUCN Red List Index to minimise the risk to biodiversity from large-scale infrastructure and natural resource extraction projects
  • Government agencies rely on IUCN Red List data to guide policies such as National Parks regulations
  • Zoos use The IUCN Red List Categories to educate the public about species' status
  • Scientists use IUCN Red List data as a primary data source in their analyses and publications
  • Teachers and students use IUCN Red List data in college projects
  • Journalists use IUCN Red List data to inform their articles


A key indicator for the SDGs and Aichi Targets

SDG Goal 15 and CBD Photo: United Nations / CBD Data from The IUCN Red List are used as indicators for the United Nations Sustainable Development Goals, particularly Goal 15: Life on Land.

The IUCN Red List Index is used by the Convention on Biological Diversity (CBD) to monitor progress towards achieving the Aichi Targets.


An essential resource for global, regional and thematic reports

UN bodies, academic institutions and civil society organisations rely on the IUCN Red List to inform a range of global, regional and thematic assessments and reports. Recent examples include the:

  • Annual UN Sustainable Development Goals reports 
  • Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) Global Assessment of Biodiversity and Ecosystem Services
  • UN Convention on Biological Diversity Global Biodiversity Outlook
  • Ramsar Convention Global Wetlands Outlook
  • WWF Living Planet Report, BirdLife International State of the World’s Birds, and Royal Botanic Garden Kew’s State of the World’s Plants

The IUCN Red List Partnership

The IUCN Red List is produced by the Red List Partnership, currently: Arizona State University, BirdLife International, Botanic Gardens Conservation International, Conservation International, International Union for Conservation of Nature (IUCN), NatureServe, Royal Botanic Gardens Kew, Sapienza University of Rome, IUCN Species Survival Commission, Texas A&M University, and Zoological Society of London.

Learn more about the experts and browse the  IUCN SSC Specialist Groups directory 


The Red List Index

The IUCN Red List Index (RLI) provides a clearer view of real trends within different taxonomic groups, and for biodiversity as a whole.

The IUCN Red List Index (RLI) of species survival for mammals, birds, amphibians, reef-forming corals and cycads. Photo: The IUCN Red List of Threatened Species™ The RLI is available for groups in which all species have been assessed at least twice. Currently, the Index is available for five groups : birds, mammals, amphibians, corals and cycads.

The RLI clearly demonstrates that the status of these five major groups continues to decline.

  Read more about the science behind the assessments 


Far more than a list of species and their status

The IUCN Red List is an authoritative indicator of the health of the world’s biodiversity. The IUCN Red List is:

  • a powerful tool to inform and catalyse action for biodiversity conservation and policy change,
  • critical to protecting the natural resources we need to survive. 
  • provides information about range, population size, habitat and ecology, use and/or trade, threats,
  • provides information about conservation actions that will help inform necessary conservation decisions. 

We welcome your support

The IUCN Red List aims to assess 160,000 species by 2020 and relies on donations to fund the assessment and reassessment of species.

  Visit the Red List website
  Download the Red List brochure


Key support

The IUCN-Toyota Partnership established in 2016 is helping us achieve our 2020 target.

Contact us and see how you can get involved!


Read more and explore

Science behind the IUCN Red List of Threathened SpeciesTM

  Read more about the science behind the categories  ¦  Read more about the science behind the assessments 

Learn more about the experts and browse the  IUCN SSC Specialist Groups directory 

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You will find useful resources and especially online training on the IUCN Red List website.


Latest press releases

  • Africocypha varicolor 16% of the world's damselfly and dragonfly species are threatened with extinction, including Africocypha varicolor, a species found only in two streams on the Moyabi-Madzay plateau in Gabon.   Photo: André Günther

    Dragonflies threatened as wetlands around the world disappear - IUCN Red List


    Gland, Switzerland, 9 December 2021 (IUCN) – The destruction of wetlands is driving the decline of dragonflies worldwide, according to the first global assessment of these species in today’s update of the IUCN Red List of Threatened Species™. Their decline is symptomatic of the widespread loss of the marshes, swamps and free-flowing rivers they breed in, mostly driven by the expansion of unsustainable agriculture and urbanisation around the world.

  • European Bison (Bison bonasus) European Bison (Bison bonasus) Photo: Rafał Kowalczyk

    European bison recovering, 31 species declared Extinct – IUCN Red List


    Gland, Switzerland, 10 December 2020 (IUCN) – The European bison (Bison bonasus), Europe’s largest land mammal, has moved from Vulnerable to Near Threatened thanks to continued conservation efforts, according to today’s update of the IUCN Red List of Threatened Species™. With this update, 31 species also move into the Extinct category, and all of the world’s freshwater dolphin species are now threatened with extinction.

  • A ring-tailed lemur sitting on a tree branch The ring-tailed lemur (lemur catta) is listed as Endangered on the IUCN Red List. This lemur is found in the dry forests, spiny bush, montane forest, mangroves, rocky outcrops, and one rainforest in southern and south-western Madagascar, and in one humid forest in south-eastern Madagascar. Despite the species' large range and flexibility, its population density is often very low and populations are largely restricted to isolated forest fragmentsExperts suspect that its population has declined by at least 50% over a three-generation period.  Photo: Zwennie (CC BY-SA 2.0)

    Almost a third of lemurs and North Atlantic Right Whale now Critically Endangered - IUCN Red List


    Gland, Switzerland, 9 July 2020 (IUCN) – Almost a third (31%) of all lemur species in Madagascar are now Critically Endangered – just one step away from extinction – with 98% of them threatened, according to today’s update of The IUCN Red List of Threatened SpeciesTM. This update completes a revision of all African primate assessments, concluding that over half of all primate species in the rest of Africa are under threat. This update also reveals that the North Atlantic Right Whale and the European Hamster are now both Critically Endangered.

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