Nevertheless, the statistical evidence to support this relationship was weak, owing to our unavoidably small sample size. bird species that are restricted to the indomalayan region, lay few eggs, are heavier, and occupy a narrower habitat breadth, were most vulnerable to extinction on pulau bintan. this was the only island where sufficient data existed to analyze the correlates of extinction. forest preservation and restoration are needed on these islands to conserve the remaining forest avifauna. our study of landbridge island indicates that deforestation may increasingly threaten southeast asian biodiversity.