About two decades ago, orangutans were classified as only one species: Pongo pygmaeus or the Bornean orangutans. Now, the animals are classified as two difference species under the Pongo genus. They are P. pygamaeus and P. abelii, otherwise known as Sumatran orangutans, which once considered the species’ subfamily (Ahrens). The reason for this change was due to the phenotypic differences between the Bornean and Sumatran orangutans. Differences include Sumatran orangutans having longer hair and faces, being thinner than Bornean orangutans, and having paler, red coats (Lang). Meanwhile, Bornean orangutans have darker, brown hair. They are also known to be less social, but have more robust bodies than P. albelii. The two species are also geographically …show more content…
The average male weight is about 192 pounds and females are about 81.6 pounds (San Diego). The species of primate are primarily arboreal; they only traverse the ground occasionally. Brachiation is used mostly in short distances, and quadrupedal locomotion is used once on the ground. Orangutans are diurnal, but also make day nests to take naps during the day. They are omnivores and have a diet that mainly consists of fruits, leaves, bark, nuts, seeds, insects, and honey (San Diego). There are two difference types of male orangutans: flanged and unflanged. Flanged males have bulging cheek pads called flanges, while unflanged males look like adult females. This species of primates are the only species where this biological phenomenon happens (WFF …show more content…
The males are usually intolerant of each other in adulthood and will threaten one another using calls, stares, shaking of tree branches, and sometimes the inflation of throat poaches. Breaks from solidarity are typically for reproductive reasons, which then the male will leaves a few days after the female becomes pregnant. Females are less solitary and are semi-social, with adolescent females being the most social (Ahrens). Young orangutans, in general, usually establish friendships with their same sex & age mates and socialize with them, as well as with their mothers. Social behavior includes playing, such as tickling and wrestling (usually between mother and infant), grooming, traveling with others, communication, along with aggressive displays noted before. Orangutans communicate using displays, visual signs, and calls. Very loud calls produced particularly by flanged males are known as long calls. A flanged male uses this call primarily to alert other males, along with sexually receptive females, of his presence. There is also no strict social hierarchy as observed in other primates, and social contact is loose and usually not permanent (San