For each species (and lower taxa) in the Dutch Caribbean Species Register we have noted on which island(s) they have been recorded. Per island, we have also judged its presence status. The following categories are used and can be searched on:
- Indigenous (code 1): species/taxon is indigenous to the island (native species, and established new arrivals and vagrants by natural means).
- Introduced (code 2): species/taxon has been introduced to the island by humans, and is now reproducing there. Includes incidental escapes/imported species.
- No longer present (code 0): species/taxon used to be present (established or frequently occurring) on an island, but is now no longer present or occurring due to e.g. local or global extinction or extirpation/eradication.
Available options for the Dutch Caribbean as a whole (instead of per island) are:
- Extinct - globally (code 0): species/taxon is globally extinct. These taxa are also registered as “No longer present (0)” on the island(s) where they used to occur.
- Data deficient (code 3a): species/taxon reported for the islands, but there is inconclusive or no evidence at all that the report is correct. E.g. species mentioned once in doubtful source, without collection material as evidence.
- Incorrectly reported (code 3b): species/taxon reported for the islands, but incorrectly, e.g. as result of a wrong identification.
- To be expected (code 3c): species/taxon not reported for the islands yet, but expected to occur in the near future on the basis of reports in nearby areas/islands (e.g. marine species with a Caribbean-wide distribution, migrant birds that are known from nearby islands, or invasive species which disperse rapidly in adjacent areas).
- Incorrectly used name/auct. (code 3d)
The following definitions are used to identify endemicity.
- Island endemics: species or subspecies that are only known to occur on one of the islands (Aruba, Bonaire, Curaçao, Saba, St. Eustatius or St. Martin (including the French part) or the Saba Bank.
- Endemics: species or subspecies endemic to larger geographical areas (e.g. Northern Lesser Antilles endemics, Lesser Antilles endemics, etc.)
- Potential endemics: species or subspecies endemic to one or more of the surrounding islands (Anguilla, St. Barthélemy, St. Kitts and Nevis), not known for the SSS islands, that potentially could have counterparts on the SSS islands or Saba Bank.
Endemism is a geographically defined term. It requires to be explicit about what geographical scales are used. Here we use the distinguished levels of endemism as used in the report on endemic species of Saba, St. Eustatius and St. Maarten (2018):
- Island level endemic species: species with a distribution that is restricted to only one of the Dutch Caribbean islands or Saba Bank.
- Bank level endemic species: species occuring on one or more islands that formed a single island in the prehistoric past with one of the SSS islands.
- Northern Lesser Antilles level endemic species: species found on one or more of the SSS islands that are restrictively shared with the islands from Puerto Rico to and including Montserrat. This includes all inter-lying islands and banks such as St. Croix, the Saba Bank, Anguilla Bank and the St. Kitts Bank islands.
- Lesser Antilles level endemic species: species found on one or more of the SSS islands that are restrictively shared with the islands of the Lesser Antilles (all islands between Anguilla and including Grenada).
- Antilles level endemic species: species found on one or more of the SSS islands that are restrictively shared with the islands of up to the Greater Antilles (all islands between and including Cuba. The Bahamas and Turks and Caicos are excluded).
- 'Other level' endemic species: species found at regions larger than the Antilles.