Species are assessed based on their risk of extinction. The threat category is determined by a combination of various criteria. These include population size, the number of mature individuals, population trend, the condition of the habitat, the size and continuity of the species’ range, and existing conservation measures. In addition to the global classification, species are also classified nationally or regionally according to the same guidelines.
Species listed as Vulnerable (VU), Endangered (EN) or Critically Endangered (CR) are considered to be threatened.
 | Species that have been evaluated as Least Concern are widespread and abundant. They don’t appear to be facing any imminent threats. |
 | Near Threatened species are close to becoming threatened or may meet the criteria for threatened status in the near future. |
 | Vulnerable species possess a high risk of endangerment. |
 | Endangered species possess a very high risk of extinction. |
 | Critically Endangered species possess an extremely high risk of extinction. |
 | A species is Extinct in the Wild when it is known only to survive in captivity, or as a naturalized population outside its historic range. |
 | A species is Extinct when there are no known living individuals. A species can be extinct either globally (EX) or regionally (RE, Regionally Extinct). |
Not all species have been assessed
The extinction risk of not all species has yet been assessed, or a species may have been decided to be left as Not Evaluated (NE) in a local classification. In Finland, these include, for example, alien species that have spread into the country with human assistance and species that live only in habitats created by humans.
Sometimes there is insufficient information about a species’ abundance, distribution, or population status to assess its risk of extinction. The species is then classified as Data Deficient (DD). More information is needed to place the species in the correct category, and until its risk of extinction can be assessed, it should be treated in the same way as species classified as threatened.
Global and national assessments
The assessments of the International Union for Conservation of Nature IUCN examine species’ risk of extinction at the global level, and species are placed in categories based on this assessment. Detailed species-specific assessments can be viewed on the Red List website. IUCN updates the list regularly, so a species’ threat category may improve or worsen as its situation changes.
In addition to the global classification, species are also classified nationally or regionally according to the same guidelines. For some species, the situation may be worse or better locally than it is globally. The Finnish Red List is coordinated by the Finnish Ministry of the Environment. It complies with the IUCN Red List categories and criteria, and the assessments are published in the Red List of Finnish species.
