Islands exhibit the planet’s most unique flora and fauna, but biodiversity on islands is also vulnerable to the impending forces of global change. The Micronesian high island of Pohnpei exemplifies the diversity of oceanic islands, as it is home to the world lowest montane-cloud forest, vast mangrove forests, and 6 endemic bird species. We conducted a survey to assess the status of Pohnpei’s current bird population. We estimated detection rates across elevation zones, habitat-specific occupancy rates for 13 species, and habitat specific densities for 10 species. We coupled results with data from previous surveys to assess the potential impacts of vegetation change on Pohnpei avifauna during the last three decades. We created computer models to estimate total extant populations of 10 species and to simulate the effect of potential future anthropogenic and climate-driven landscape change on Pohnpei avifauna. We used a series of 1,000 simulated possible future conditions that incorporated ranges of expanded and new agricultural plots and secondary vegetation. We also simulated the effects of climate-driven changes to upland vegetation and of sea level rise on mangroves. This work allowed us to identify key forces affecting each bird species, and sea level rise and the associated changes to mangroves were found to most impact 7 of 10 species analyzed. Further, the expansion of anthropogenic vegetation ranked first or second in 5 of the 10 species. Together, results indicated that protection of mangrove systems, and regard for native vegetation in areas near existingsettlements, are valid future courses for conservationists. Because birds can be use as forest-health indicators we believe that special attention should be lent to future forest management plans. Considering that many islands across the Pacific have identical or similar habitats and congeneric bird species, we further believe the tools we developed could be applied to bird conservation elsewhere.
