Characteristics Of Bornean Orangutans

Orangutans are the ape that inhabits the rainforests of Southeast Asia. Orangutans are under kingdom Animalia. Cushman (2014) stated that orangutan is also known as the ‘People from the Forest’ in Malay. Orangutans are classified into two subspecies which is Bornean orangutans and Sumatran orangutans (Pongo abelii) as they differ slightly in appearance and also behavior. Focusing on Bornean orangutans, its scientific name is Pongo pygmaeus (Strobel, 2010). According to Lang (2010), Bornean orangutans are long lived just like many of the great ape species as they always live more than 50 years in the wild. Therefore, there are some characteristics of the Bornean orangutans in terms of its endemic, morphology and physiology.

The

Morphology of Bornean orangutans is defined as the physical structure and form of the Bornean orangutans. Bornean orangutan has different characteristics than Sumatran orangutan where Bornean orangutan has broader face, shorter beard and slightly darker in color (World Wild Life, 2015). Besides that, the male Bornean orangutan has cheek pad where it is flat and covered with downy hair and longer beard with moustache (Groves, 1971). The cheek pad is also known as flanged that can produce ‘long call’. As mentioned by Orangutan Foundation International (2015), the ‘long call’ is very important during the competition between the male Bornean orangutan and its rival to persuade the female orangutan for mating. Meanwhile, according to Groves (1971), the female Bornean orangutan has beard on its flatter and elongate O-shaped face. As mentioned by Cushman (2014), Bornean orangutan can reach to 1.5 metres tall, weight up to 90 kilograms, and the arm span can be as long as 2.5 metres. Its arm is relatively longer than its leg which is twice longer. The long arm span makes it graceful and agile while climbing through the trees but it makes walking on the forest ground slow and awkward. According to Sea World Parks and Entertainment (2015), the hips of Bornean orangutan can move freely where its’ joint can rotate fully and help the legs move at any

Physiology of Bornean orangutan is divided into three categories which are reproduction, behaviour and survival. According to Galdikas and Insley in 1988, a flanged male uses this call primarily to alert other males to his present location to sexually receptive females. There is some evidence that the ‘long call’ plays an important role in the suppression of development among adolescent and sub-adult males (Galdikas & Insley, 1988). While sub-adults flee from the sound of ‘long calls’, sexually receptive females use it as a tracking device for flanged males and respond accordingly. Rijksen (1978) stated that, because of orangutan has the semi-solitary nature, adult males have no contact with infants and therefore no parental investment in the wild. Hence, the primary care provider and instrument of socialization for offspring is the orangutan mother. The strongest, most salient social group among orangutans involves an adult female and her dependent offspring (Rijksen, 1978). Besides, Bornean orangutan is a warm-blooded species. This has helped them in maintaining their body temperature by cooling down or producing more body heat. Hence, they control their metabolic rate for instance, if the temperature outside decreases, the metabolic rate will increase. British Broadcasting Corporation (BBC) (2010) mentioned that the hotter the sun gets, it will make the Bornean orangutan sweats more. Sweating is a