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

Abstract

Unprecedented rates of deforestation on tropical islands are threatening high numbers of endemic species, and empirical evidence is needed to better understand the implications of changes in land-use on biodiversity and to guide conservation actions. We assessed the effects of changes in land-use on the lowland 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 types of land-use 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 as intensity of land-use increased. There were significant differences in the occurrence of functional groups between habitats. Fifteen of the 42 species observed showed significant variation in abundance across habitats. Of those species that varied, 12 were endemic to Makira or to Melanesia, with seven of these endemics being absent from the monoculture Cocoa plantations. As tropical islands have less functional redundancy than continental land masses, protecting the remaining forest and improving habitat connectivity will be even more critical for conserving their endemic species and maintaining ecosystem functioning.