The Red List of threatened species

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juin 2021

A reference tool in conservation, the Red List is an assessment system that lists all current knowledge about animal and plant species, the ecosystem input they provide, the threats they face, and the conservation measures they benefit from.

It is the most comprehensive source of information on species and their worldwide conservation status. Each species is categorised according to its health status and its risk of extinction. With the aim of assessing all species, whether threatened or not, the Red List is a barometer of living organisms because it indicates where the emergencies are and what threats weigh on biodiversity in order to guide priority conservation actions. This tool makes it possible to take biodiversity protection into account in decision-making, whether on a government, a non-governmental organisation (NGO) or the private sector level.

Its usages

  • In the conservation field, it facilitates decision-making in species protection measures or in identifying priority areas and species for conservation.
  • The IUCN results are a reference in research and guide work. By pointing out certain gaps in our knowledge of biodiversity, the Red List can guide future research.
  • In politics, the Red List is used to inform decision-makers of the consequences of their development projects on biodiversity, notably through impact studies. The Convention on Biological Diversity (an international treaty aimed at encouraging sustainable measures), for example, uses these data to evaluate strategic decisions by governments and politicians.
  • The Red List contributes to educating the general public; its results are used by teachers and students in class projects, and also by the network of zoological parks and aquariums which display the protection status on their educational materials
  • In the medical field, it completes the study of disease vector species to prevent and control epidemics.

Red List categories

The Red List is made up of categories that allow species to be classified according to their risk of extinction using objective criteria. Once classified, it is possible to compare the number of species that are threatened from one region to another in order to define priority conservation areas.

For some species, we do not have sufficient data to define a conservation status. This does not mean that these species are not threatened, but simply that it is not possible at this time to define their status.

IUCN Red List categories

Threatened species (CR, EN and VU) are evaluated according to precise and quantitative criteria that take into account the demography of a species and its evolution over time. For each of these criteria, there are levels that correspond to the different statuses.

Let's take a concrete example: in Martinique, the Sperm Whale (Physeter macrocephalus) falls within the Endangered (EN) thresholds for criterion D but the Vulnerable (VU) thresholds for criterion A. The IUCN status of the Great Sperm Whale in Martinique is therefore Endangered (EN) according to criterion D because the most serious status is always taken.

  • Criterion A – Significant reduction in population size
  • Criterion B – Restricted and declining area of geographic distribution
  • Criterion C – A small and declining population
  • Criterion D – A tiny geographical distribution or a very small (and abnormal) population
  • Criterion E – Quantitative analysis (Population Viability Analysis) shows a high risk of extinction

There is a worldwide Red List of species. The French Committee of the IUCN and UMS PatriNat (OFB, CNRS and MNHN) have developed it at national and regional scale.

The Red List and the French West Indies

France, with its diverse landscapes and its overseas territories, benefits from great but sometimes very fragile biodiversity: it is one of the 10 countries with the most threatened species in the world. In the West Indies, the declining species is notably caused by the introduction of invasive exotic species, poaching, light pollution linked to urban development, and the use of toxic substances such as chlordecone, etc.

In the Lesser Antilles, Martinique and Guadeloupe are the only islands to have a Regional Red List. At present, we do not have any figures concerning the status of the populations on the islands of Saint-Martin and Saint-Barthélemy.

However, all the French overseas regions are home to exceptional biodiversity; they are a priority for the French Committee of the IUCN, which has designed the Overseas Program to meet the needs of local stakeholders sometimes faced with a lack of human and financial resources.

Cetaceans and the Red List

Among the thematic groups of the IUCN’s Species Survival Commission (SSC), a Cetacean Specialist Group (CSG) was founded in the 1960s. It is in charge of the Red List of cetaceans worldwide and its regular update.

A council of experts spread around the world identifies threats to cetaceans. It then informs governments and NGOs of the conservation measures to be taken to safeguard and protect the animals.

In the French West Indies, 2 species are threatened: the Humpback Whale and the Sperm Whale


The International Union for Conservation of Nature is the world's largest and oldest network for the environment and biodiversity. It is a collection of organisations (governments, scientific institutions, indigenous peoples' unions, NGOs, etc.). The IUCN is made up of volunteer scientists and experts in a wide variety of fields from all over the world and is responsible for making major decisions on the environment and nature conservation. It is the only environmental organisation with observer status at the United Nations General Assembly, which allows it to communicate the policy perspectives of its members at the highest level of international diplomacy.

Its actions

IUCN's volunteer experts are divided into six commissions that deal with general issues, such as ecosystem management and environmental, economic and social policies.

Among them, the Species Survival Commission brings together experts in animal and plant species organised in thematic working groups (specialist groups for cetaceans, sharks, sea turtles, invasive species, etc.). The aim of this commission is to gather as much knowledge as possible on species in order to evaluate their conservation status. This assessment is carried out based on the Red List and enables appropriate conservation tools to be proposed in order to prevent the extinction of species.