Conserving the seychelles warbler Acrocephalus sechellensis by translocation from Cousin Island to the islands of Aride and Cousine

Abstract

The Seychelles warbler Acrocephalus sechellensis was once a highly threatened single-island endemic species with a population of 26 individuals confined to Cousin Island in the inner Seychelles. Following long-term management of Cousin, the population steadily recovered to around 300–360 birds. Given the vulnerability of one small island in the Indian Ocean, the possibility of establishing the species on additional islands had been proposed as a priority conservation measure, in order to give the species the security of additional breeding populations, lest some ecological disaster should befall the parent population. Successful translocation of warblers to the islands of Aride and Cousine took place in September 1988 and June 1990 respectively. Given the presence now of three healthy breeding populations, it is considered that the Seychelles warbler will soon no longer be a globally threatened species. It is not often that people are allowed to pull a species so dramatically back from the brink of extinction.