Assessing the threat status of species

The assessment of threatened species evaluates species’ extinction risk. Together with data on species’ locations, the assessment contributes to the needed knowledge base for prioritising, planning and implementing measures that conserve species and their habitats at local, regional and national level. The primary purpose of the assessment is to provide information as comprehensive and up-to-date as possible on the extinction risk of species living in Finland and of the status of Finnish flora and fauna as a whole. In addition, the reoccurring assessments offer the possibility to examine changes in development trends, which further increases the value of the results.

The Red List 2019 is the fifth Finnish assessment of threatened species that covers all organism groups. It complies with the Red List Categories and Criteria of the International Union for Conservation of Nature (IUCN) and the accompanying guidelines for application. The IUCN Red List Categories and Criteria provide a consistent system for classifying species’ extinction risk and their threat status. Extensive consultation and testing in the development of the system strongly suggests that it is robust with respect to most organisms. Originally, the IUCN Red List system was developed for classifying species at high risk of global extinction, i.e. for assessment at global level. However, the system can also be applied at a regional level.

Species classified as Critically Endangered (CR), Endangered (EN) and Vulnerable (VU) are threatened. Placing species into the threatened categories is based on quantitative criteria designed to reflect the degree of extinction risk. A taxon is Near Threatened (NT) when, at the time of the evaluation, it does not fulfil the criteria for being threatened but is close to doing so. Assigning a species to the category Data Deficient (DD) indicates that the data are so inadequate that the species’ risk of extinction cannot be assessed and that any category from Least Concern (LC) to Critically Endangered (CE) is plausible. These species should be treated in the same way as threatened species at least until their risk of extinction has been assessed.

The categories Extinct (EX) and Extinct in the Wild (EW) can only be used in regional evaluations if the extinct species has been endemic to the region. These categories have not been used since no species or lower taxa that are without doubt endemic to Finland (occurring exclusively in Finland) are known to have become extinct from the country. The species that are included in the classification but excluded from the evaluation are listed in the categories Not Evaluated (NE) and Not Applicable (NA) and no attempt has been made to assess their risk of extinction.

Five criteria are used in assessing the threat status of species to evaluate if the species in question belongs to one of the threatened categories. If the species does not meet the conditions of the threatened categories (VU-CR) for any criteria, it is either Near Threatened (NT) or Least Concern (LC). If a species does not fall into any clear category despite the evaluation attempt, the species may be Data Deficient (DD). The criteria analyse the species’ populations and their development in relation to the species’ lifecycle (generation length). The criteria also include subcriteria, which are used to specify the species’ classification and the rationale behind it.

The organisms examined in the assessment of threatened species are wild populations of species living permanently inside their natural range in Finland. The evaluation criteria should not be applied to alien species, or species vagrant or unestablished in Finland.