The effects of land-use change on endemic avifauna on Makira, Solomon Islands : endemics avoid monoculture

Abstract

Unprecedented rates of deforestation on tropical islands are threatening high numbers of endemic species. A lack of empirical evidence for the impacts of land-use change on biodiversity is hindering conservation activities in these regions. We assessed the impacts of land-use change on the avifauna of the tropical island of Makira in the Solomon Islands. We examined species richness and community assemblages, with a particular focus on endemism and functional traits, to provide further insight into the 'conservation value' of the dominant land-use types present on Makira (i.e. intact forest, secondary forest, food gardens, mixed cocoa plantations, and monoculture cocoa plantations). We found species richness was similar across habitats, but endemic species richness decreased in more intensive land uses. There were significant differences in the occurrence of functional groups between habitats. Fifteen out of the 42 species observed (35%) showed significant variation in abundance across habitats. Of those species that varied, 80% were endemic to Makira or to Melanesia, with seven of these endemics being absent from the monoculture cocoa. As tropical islands have less functional redundancy than continental landmasses, protecting the remaining forest and improving habitat connectivity will be even more critical for conserving their endemic species and maintaining ecosystem functioning.