mainlandasia-2 Figure: sunda_map_migration The land bridges between Sumatra, Java, Borneo and mainland Asia allowed orangutans from these areas to re-claim habitat in Northern Sumatra after the explosion of Toba volcano eliminated the original population. When sea levels rose after the last ice age, the islands and the mainland became isolated from each other again. The orangutan populations on Java and the mainland later became extinct. Today, orangutans are only found on Sumatra and Borneo. Figure: sunda_map_migration