The potential for conservation of Polynesian birds through habitat mapping and species translocation

Many populations and species of Polynesian land birds, particularly pigeons, doves, parrots, kingfishers, and passerines, are likely to become extinct within the next few decades unless we intervene to save them. One strategy is to translocate species onto previously occupied islands, if the habitat is suitable and current human activities are compatible. The method evaluated a procedure for analyzing terrestrial habitats in a geographical information system using aerial photographs, satellite imagery, topographic maps, and thematic maps. In the relatively simple island ecosystems of Atiu and Mitiaro (southern Cook Islands), mapping land cover and evaluating habitat suitability of land birds is straightforward; measures of the shape and spatial relationships of land cover patches are of limited value. Even small disturbances can eliminate a significant proportion of preferred habitat for land birds. Whenever possible, translocation efforts should focus on islands uninhabited by humans. The potential for successful translocation in the Cook Islands is limited to a few species. In Tonga, where more species of birds have been extirpated and where there are more uninhabited islands, the potential to reestablish viable land bird populations is much greater. -from Authors