Bats are most vulnerable to overhunting in Indonesia, the Philippines, Malaysia, and islands of Oceania and the Indian Ocean. Bats are susceptible to overhunting as they have naturally low rates of reproduction and many species are highly colonial, which makes it easier for them to be hunted in large numbers.[20] Overhunting is believed to be the primary cause of extinction for the small Mauritian flying fox and the Guam flying fox.[27]