The avifauna of Semau Island, Lesser Sundas, Indonesia: Ecology, Taxonomy and Conservation

The avifauna of Semau, a small island (261 km2) near southwest Timor in the Nusa Tengarra region of Indonesia, is reviewed, based on a series of visits comprising some 18 days between October 1989 and May 1991 and a further two days in August 2012. The birdlife present is a species poor subset of that on Timor (30720 km2), with all resident breeding landbird species except the Orange-footed Scrubfowl Megapodius reinwardt occurring on that island.  One of the shared species is, however, represented by an endemic taxon, the White-bellied Bushchat Saxicola gutturalis luctuosa, which constitutes the only record of island endemism. The observations obtained and the specimens collected are compared with the last major, comprehensive review of the Wallacean Region, that of White and Bruce (1986). Some 56 additional species were recorded, comprising 17 resident landbirds and many migratory northern hemisphere and seabird taxa, but also including some drought refuge waterbirds from Australia. The taxonomy of collected material and, where possible, the birds observed are reviewed with reference to both White and Bruce (1986) and more recent studies. Where these results indicate that Semau is located within an intergrade zone, for instance between the two taxa indica and longirostris of the Emerald Dove/Green-winged Pigeon Chalcophaps indica, we refer to adjacent islands. Despite the impoverished avifauna, some 13 species of restricted-range birds (including the endangered Timor Green Pigeon Treron 163 psittaceus) have been recorded. We also cite previous ornithological surveys, and assess species turnover. There has been two introduced passerines, and some recent apparent declines, principally of forest species, as a result of habitat destruction and/or capture for the bird trade.