Conservation of the herpetofauna on the Dutch Windward Islands: St. Eustatius, Saba, and St. Maarten

摘要

The Dutch Windward Islands (St. Eustatius, Saba, St. Maarten) support a collective herpetofauna consisting of two frogs (both introduced), six turtles (one introduced, one of uncertain origin, and four sea turtles, of which three are known to nest in the islands), 15 or 16 lizards (depending on whether the iguanas of Saba are a species distinct from Iguana iguana), and three snakes (one introduced). Although politically united, the islands are distinct biogeographic entities and binary similarity indices for the herpetofauna are 0.38 for St. Eustatius/Saba, 0.35 for St. Eustatius/St. Maarten, and 0.20 for Saba/St. Maarten (with values varying only little when the introduced species are included). Only three species, Eleutherodactylus johnstonei, Hemidactylus mabouia, and Thecadactylus rapicauda, are found on all three islands. Species given formal recognition as being in need of protection include the sea turtles (listed in CITES appendices and the IUCN Redlist), Geochelone carbonaria (CITES), Iguana delicatissima (CITES and IUCN), Iguana iguana (CITES), and two species of Alsophis (IUCN). Other species of conservation concern include two species of Ameriva, both of which are restricted to areas of considerable human activity on islands where mongooses (Herpestes javanicus) are established, and Mabuya sp., which may be extirpated on St. Maarten.