Population sizes and the conservation status of endemic and restricted-range bird species on Karakelang, Talaud Islands, Indonesia

Abstract

Karakelang, largest of the Talaud Islands, Indonesia, was visited in 1999 with the aim of producing population estimates of globally threatened and Restricted-range bird species. Density estimates were calculated from primary forest and secondary habitats using the variable circular plot method. Eight of the nine restricted-range or threatened species resident on Karakelang were recorded and density estimates calculated for five of these. Two species of rail are endemic to Karakelang, Talaud Bush-hen Amaurornis magnirostris and Talaud Rail Gymnocrex talaudensis. The bush-hen was encountered in secondary habitat but occurred at higher densities in primary forest and the estimated population was 2,350–9,560 birds. The less vocal, cryptic G. talaudensis was noted just twice, in primary forest close to rivers. Both have small populations, are threatened by habitat degradation, hunting, and possibly predation by introduced rats and should be classified as threatened. Population densities of the Endangered, endemic Red-and-blue Lory Eos histrio had remained stable since the last survey in 1997. They occurred at higher densities in primary forest, but were also common in human-made habitats. The estimated population was 8,230–21,400 birds, threatened by habitat loss and trapping for the wild bird trade. Although more commonly encountered in forest, the Near Threatened Blue-naped Parrot Tanygnathus lucionensis was found at higher densities in secondary habitats, and the population was estimated at 8,130–20,700 birds. The Restricted-range Blue-tailed Imperial Pigeon D. concinna was very common on Karakelang (14,500–27,700 birds), whilst the Vulnerable Grey Imperial Pigeon D. pickeringii was recorded rarely; both species were more frequently recorded in primary forest. The endemic Talaud Kingfisher Halcyon enigma occurred at low densities (5,290–8,690 birds), in primary forest and adjacent disturbed areas. It is heavily dependent on primary forest and threatened by habitat loss, and should be classified as Vulnerable. Approximately 350 km² of primary forest on Karakelang is protected, 250 km² as a wildlife reserve. However, at present, management is absent and forest is threatened by agricultural encroachment, illegal logging, and fire. Given that all endemic and threatened species were encountered more frequently or occurred at higher densities in primary forests, future conservation efforts should target these protected areas. Management of reserves should involve local stakeholders from government and representatives of island communities. Wildlife trade is a major threat to Eos histrio and strict enforcement of the species' protected status should include monitoring of roost sites, patrols of harbours and markets in Talaud, Sulawesi and the Philippines, and the control of Philippine fishing boats involved in the wild bird trade. Further species-specific research and monitoring is also required.