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). These great apes possess long reddish hair, long arms, and hooked hands and feet for travelling at the canopy. Due to their dispersed and cryptic nature, it can be hard to find them in the wild if they do not make nests around an area (Meijaard et al., 2010). However, the ones in captivity in Sepilok Orangutan Rehabilitation Centre near Sandakan, Sabah are a bit extroverted; they like to model for the many tourists who visit the Centre.

Orangutan are frugivorous because fruits make up more than 60% of their average total daily food intake (Wich et al., 2006), even though leaves, bark, flowers and insects are also part of their diet. “Natural gardeners” of the forest is another description for them as they help in seed dispersal. Orangutan exhibit bimaturism or two morphological forms of mature males. The size of the dominant flanged males is double that of the females. 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. One of the reasons for this is because peat swamp forest have high densities of valuable timber (Whitmore, 1984) and commercial logging is permitted in some areas. Orangutan distribution is highly patchy throughout Borneo Island as large canopy gaps hinder their movement. Changes in forest structure due to selective logging could have negative effects on their population densities (Felton et al., 2003). Their main threats are land conversion to agriculture, forest fire, poaching, and the illegal pet trade. A recent study showed that past populations were more abundant than at the present (Meijaard et al., 2010). According to Acrenaz et al. (2008), the status of orangutan is endangered. The number of orangutan present in Sabah is only about 11000 out of a total of 54000 in Borneo and is now declining.