Author: Thibault, Jean-Claude
Title: L’avifaune des îles Eiao et Hatuta’a (Polynésie, Pacifique sud): modifications intervenues au XXème siècle
Journal: L’oiseau et la Revue française d’ornithologie
Keywords: Eiao; Hatuta’a; avifaune
Abstract: 24 species of breeding birds are known from Eiao and Hatuta’a (Marquesas Is., South Pacific Ocean). Comparisons of collections and observations from the first half of this century (1922, 1929) with those made recently (1975, 1977, 1987) allow changes to be studied. Hatuta’a was visited by the Polynesians (who left behind stone pavements and introduced Rattus rattus), but their impact on the terrestrial ecosystem is uncertain. This century has not seen important changes in either the composition of the avifauna or the abundance of species, except for establishment of a new breeding seabird. Althought its surface area is only a third that of Eiao, the island is of considerable faunistic interest. In contrast, Eiao (52 km 2) has suffered major disturbance at different times: woodland clearance, construction of buildings and workshops, probable introduction of pigs and Rattus exulans by the Polynesians, then occupation by westerners who attemped pastoral farming (intoduction of sheep) between 1870 and 1930. Today the soil is bare over most of the surface of the island as a direct consequence of overgrazing by the sheep. The occurence of woody plants is now limited to a few groves. The distribution of the only endemic passerine bird that still survives there (Acrocephalus caffer) is confined to several areas that still support shrubby and woodland vegetation. During the past century an endemic bird has become extinct (Pomarea iphis fluxa) and an introduced species present for several decades in the archipelago has become established (Lonchura castaaneothorax).