Habitat selection by terrestrial birds on Pemba Island (Tanzania), with particular reference to six endemic taxa

摘要

An important proportion of the world's biodiversity is found on oceanic islands. Island endemics frequently have small populations and are known to be sensitive to habitat and community changes, making them prone to extinction. In this paper, we assess the habitat distribution of the terrestrial birds of Pemba, an oceanic island that has been classified has an "Endemic Bird Area". Most of Pemba has been profoundly altered by human activities and only small patches of natural vegetation remain. However, we found that the six endemic birds (four species and two sub-species) have colonised several of the man-made habitats, including clove plantations and farmland, and remain widespread. Species richness was not reduced in these heavily managed areas when compared to the remnants of tropical forest. Nonetheless, the main strongholds of some endemic species are in habitats which have substantially declined in recent years, and which are likely to be further reduced in area in the medium and long term. For these endemics, particularly the Pemba scops owl (Otus pembaensis), the conversion of areas that were formerly clove plantations to open farmland should be considered a serious threat.