The orangutan jaw appears to have adapted to specialized diets in Borneo and Sumatra. Orangutans in general prefer fleshy fruit, but in parts of Borneo, limited fruit yield can force orangutans to consume bark and tougher vegitation. Given the dietary differences, it follows that Pongo pygmaeus (Borneo) has a jaw that can resist greater loads than the jaw of Pongo abelii (Sumatra). Among the Borneo subspecies, Pongo pygmaeus morio and Pongo pygmaeus wurmbii can tolerate the largest forces, followed by Pongo pygmaeus pygmaeus and Pongo abelii (Sumatra). This variation is again likely due to food type and availability.