Land birds of Tuamotu Archipelago, Polynesia: relative abundance and changes during the 20th century with particular reference to the critically endangered Polynesian ground-dove (Gallicolumba erythroptera)

We report relative abundances and distributions of land bird communities on eight isolated islands of the Tuamotu Archipelago (Polynesia, South Pacific Ocean) during two 21-day expeditions in 1999. The selection of islands was based on the historical range of the Polynesian ground-dove (Gallicolumba erythroptera), in the hope of finding populations of this critically endangered species. Data were also collected on the Tuamotu sandpiper Prosobonia cancellata, the Atoll Fruit-dove Ptilinopus coralensis, the Tuamotu reed-warbler Acrocephalus atyphus, the Spotless Crake Porzana tabuensis and the Bristle-thighed Curlew Numenius tahitiensis, and on introduced predators (cats, rats, pigs and dogs). None of the five land-bird species recorded previously, in 1922 and 1974, has completely disappeared, but ranges of several species have contracted. Only one population of G. erythroptera erythroptera was found and it is the only population known for this species today. Our data also raise particular concern for the future of the Tuamotu sandpiper.