Regionally Extinct (RE) applies to the regional population only. A RE taxon is known to still exist elsewhere and may re-colonize or be reintroduced into the region.
Extinct (EX) applies to the global population. An EX is not known to exist either within or outside the region.
“ Regionally Extinct in the Wild” There is no such category as “Regionally Extinct in the Wild”. If wild populations have been lost and the taxon now only exists within the region in captivity, but wild populations still exist outside the region, the assessment should be Regionally Extinct (RE) .
Step one – Identifying NA taxa Decide which taxa are Not Applicable (NA) for the regional Red List; this involves deciding set rules to identify NA taxa. Step two – Preliminary assessment Apply Red List criteria to the wild population occurring within the region only (exclude populations outside the region) Step three – Final regional assessment Evaluate potential rescue effects from populations outside the region and consider up- or down-listing accordingly. Regional assessment essentially a three-step process: conservation priority setting (includes other factors)
Taxa not eligible for regional assessments (NA) Step one – identifying NA taxa
Vagrant taxa (not indigenous to the region but occurs occasionally and irregularly)
Introduced taxa (not indigenous to the region and introduced for reasons other than conservation)
Marginal taxa (small proportion of global range/population within the region). A threshold may be set to determine which are included and which are NA (e.g.: if <1% of the global population is in the region, the taxon is NA).
Visiting non-breeding taxa (not breeding there, but using essential resources). A threshold may be set to determine which are included and which are NA (e.g.: if <1% of the global population is in the region, the taxon is NA).
Immigration from outside the region - Movement of individuals between regions will influence the risk of extinction within the region. The IUCN Categories and Criteria alone may produce a wrong categorization for these populations.
Endemic taxa - No populations outside the region to influence the assessment. The IUCN Categories and Criteria alone can be used. Regional assessment = Global assessment Non-endemic taxa - Non-endemic taxa may be influenced by populations outside the region:
Isolated populations - Behave as endemics. These can be assessed using the IUCN Categories and Criteria alone .
Step two – preliminary assessment
Step 2: Assess the regional population according to the Red List Criteria Step three – regional adjustment 3a. Does the regional population experience any significant immigration of propagules likely to reproduce in the region? 3d. Are the conditions outside the region deteriorating? No / unknown Downlist category from step 2 Yes likely No unlikely 3f. Can the breeding population rescue the regional population should it decline? Yes / unknown No / unknown No / unknown No change from step 2 Downlist category from step 2 No unlikely Yes likely Uplist category from step 2 Yes / unknown 3c. Is the regional population a sink? Breeding populations: Visiting populations: 3b. Is the immigration expected to decrease? Yes / likely No change from step 2 Yes / unknown No unlikely 3e. Are the conditions within the region deteriorating?
Examples from the Swedish Red List Sandwich tern Sterna sandvicensis 450 breeding pairs in Sweden. 65% decline in Sweden over the last three generations. Preliminary assessment (step 1) Endangered (EN A2ac; C1) Outside the region, there are are good immigration possibilities from the south. For example, there is a large and stable population in Germany and an increasing population in Holland. Therefore, the preliminary regional category is downgraded. Final assessment Vulnerable (VU A2ac; C1)
Examples from the Swedish Red List Caspian tern Sterna caspia 415 breeding pairs in nine colonies and 80 solitary breeding pairs in Sweden. 65% decline in Sweden over the last three generations. Preliminary assessment (step 1) Endangered (EN A2ae; C1+2a(i)) Outside the region, the Caspian tern population in the entire Baltic Sea area (Sweden, Finland, Estonia) has declined by 39% over the last three generations. The nearest population outside of this area is in the Black Sea. Probability of re-colonization from the Black Sea population is very low. Therefore, the preliminary category is left unchanged. Final assessment Endangered (EN A2ae; C1+2a(i))
Conflicting regional and global assessments Non-endemics The global assessment may differ from a regional assessment:
A taxon may be globally LC, but threatened within the region because the global population is large, wide-spread and stable, but within the region the population is small and declining.
A taxon may be globally threatened (under criterion A) but LC within the region because the population in the region is large and is not declining at the same rate as elsewhere.
Endemics In some cases there may be disagreement between the regional assessment and the current global assessment of an endemic taxon. Contact appropriate global-level Red List Authority via the IUCN Red List Unit (firstname.lastname@example.org) Conflicting regional and global assessments Vulnerable Critically Endangered
Endemics Regional and global assessor reach an agreement on most appropriate assessment and global assessment is changed. Regional Red List can include the new global category immediately, even if global Red List has not yet been updated Vulnerable Critically Endangered Vulnerable Vulnerable
Endemics Regional and global assessor do not reach an agreement on most appropriate assessment. Regional assessors may submit an appeal to the IUCN Red List Unit (email@example.com) for judgement by the IUCN SSC Standards & Petitions Working Group Critically Endangered Critically Endangered ! Vulnerable Vulnerable !
If an appeal is made and no conclusion has been reached before the regional Red List is finalized, both the regional assessment and the current IUCN global assessment should be included in the regional Red List Where global and regional assessors disagree over the assessment of an endemic taxon, the issues involved must be documented under the listing.