Orangutans are great apes found on the islands of Sumatra and Borneo. They are the only great apes which live outside of Africa. Actually, there are two species of orangutan: the Sumatran orangutan (Pongo abelii) and the Bornean orangutan (Pongo pygmaeus). Orangutans have long arms and reddish-brown hair. They are also highly intelligent. The name orangutan comes from the Malay words 'orang', which means person, and 'hutan', which means forest. Orangutans are highly endangered, less than 15,000 orangutans are thought to exist in the wild.