Criteria

In accordance with the IUCN guidelines, the five criteria (A–E) are used in assessing the threat status of species. The risk of extinction and whether the species in question belongs to one of the threatened categories is determined based on these criteria.

Criterion A

Criterion A is devised to identify the species whose populations have significantly declined in the recent past or which are estimated to decline in the near future.

Criterion B

Criterion B is designed to identify the species that have a limited extent of occurrence or area of occupancy and that have severely fragmented occurrence and/or species with continuing decline in populations and/or extreme fluctuations in populations.

Criterion C

Criterion C is designed to identify species with a small population size and a continuing decline or a projected future decline.

Criterion D

Criterion D is used to determine very small populations or species occurring in a limited area that are also characterised by the fact that they are not necessarily declining but their small number of mature individuals or limited occurrence makes them especially prone to a significant decline or extinction.

Criterion E

Criterion E is based on quantitative analysis. There are no analyses required by this criterion available on any organism group in Finland, and the criterion was hence not applied at all in the assessment.