Notes on the natural history, taxonomy, and conservation of the endemic avifauna of the Samoan Archipelago

The Samoan Archipelago is an important area of avian diversity and endemism within the tropical Pacific. Here, we summarize observations on the natural history and vocalizations of Samoan birds based on fieldwork conducted over the course of five visits to Samoa and American Samoa from 1977 to 2006 with particular emphasis on the Manu’a Islands and the highlands of Savai’i. We interpret our findings in light of modern understanding of the biological species concept to identify seven Samoan forms as previously unrecognized endemic species: Samoan Wood Pigeon Columba [vitiensis] castaneiceps, Peale’s Kingfisher Todiramphus [chloris] pealei + manuae, Manu’a Shrikebill Clytorhynchus [vitiensis] powelli, Samoan Myzomela Myzomela [cardinalis] nigriventris, Samoan Robin Petroica [multicolor] pusilla, Manu’a Starling Aplonis [tabuensis] manuae, and Samoan Thrush Turdus [poliocephalus] samoensis. The number of endemic species in the archipelago thus increases from 10 to 17. Field surveys on Savai’i reveal significant differences between highland and lowland bird communities, with several lowland species reaching their upper elevational limit at 1,200 m. We conclude that the critically endangered Samoan Woodhen Gallinula pacifica has been extinct for over a century, and suggest that recent reports are based on misidentifications. We found the Tooth-billed Pigeon Didunculus strigirostris to be Critically Endangered and in urgent need of conservation action.