Pongo pygmaeus, more commonly known as orangutan, is a large arboreal animal that is native to the island of Borneo. Orangutan means people of the jungle. There is only one genus of great apes native and extant in Asia; this consists of the Bornean orangutan and Sumatran orangutan, Pongo abelii (WWF, 2016).

They have a long coat of dark hair on the back, a facial disk, flanges and a throat sac used for long vocalisations (Acrenaz et al., 2008). The long vocalisations are used to attract receptive females (Knott et al., 2010). In addition, these males are quite bigoted and likely to be aggressive when they encounter other adult males. In contrast, the subordinate unflanged males do not possess these secondary sexual characteristics and they are almost the same size as the adult female (Acrenaz et al., 2008).

Most orangutan inhabit peat swamp forests, but most of their habitats are outside protected areas. They are highly patchy throughout Borneo Island as large canopy gaps hinder their movement.The number of orangutan present in Sabah is only about 11000 out of a total of 54000 in Borneo and is now declining.