Sumatran Orangutans: Endangered in the Extreme.

The orangutan also known as the “person of the forest” or "Old man of the Forest" is the only great ape that doesn’t

live in Africa. They live on a large Island chain of South East Asia, in Borneo and Sumatra. There are two groups of orangutans

The Borneo (Pongo pygmaeous pygmaeus) and Sumatran (Pongo pygmaeus abelii). article i will be discussing primarily Sumatran orangutans.

Sumatran orangutans vary in color from Borneon Orangutans, Sumatrans are a paler sandy or brighter orange color, as for Borneon Orangutans are more of a reddish maroon color, the skin colors can vary from light to dark and the pigmentation is frequently blotchy.

One of the most prominate characteristics of a male orangutan is that they have huge laryngeal air sacs that spread out underneath their skin on their chest, arms, and shoulders. This sac acts as resonating chambers for loud calls that can be heard for at least a mile away, they also have

huge flaps of skin known as cheek pads on each side of their faces. Males are more sexually dimorphic and weigh on an average 60% more than females. This is a function of direct male to male conflict for sexual access to a female.

      The social behavior of an orangutan is different compared to most primates. Both males and females are usually solitary, even though in captivity they are kept together. Adult females are semi-social compared to males and often live with their offspring, staying in almost constant physical contact with them for the first two years of the infants lives. Young orangutans will travel and sleep with their mothers until they reach five to seven years of age. Even as juveniles, female offspring remain to range near their mothers though they do become competitors for sexual access to the same males. Young orangutans are highly social, establishing bonds with same gender and age mates. As they approach adolescence ages 7-10 years old, males will move off on their own.

Adult males are more solitary and will make threats when meeting other males. Threatening displays often include staring, inflating their throat pouches, producing long call vocalizations, and shaking branches. Often times when males meet in the forest and their threat displays don't work to scare off a rivel, they will fight often to the death.

The age ranges of orangutans are: Infants 0-3 months of age, Juvenile 3-7 years of age in which they become more independent, searching for food on their own and no longer share nest with the mothers.

Males become more independent and sexual active between ages 8-15 (Rijksen 1978), but don’t mate until they are full grown with cheek pads, a throat pouch, and start using long calls to attract females, this is usually at the age of 19-20, but sexual display has been seen

in younger orangutans.

      There is  documentation thats shows juvenile males may try to mate with their mothers, but this happens at a young adolesent stage and is usually nothing more than just experimenting or curiosity. Even though a young male who doesn’t have a secure territory will roam around looking for a female in estrus and force copulation and successfully impregnate her; females may seek protection from sexual harassment of young

males from full adult orangutans (Fox 2002).

      Orangutans are diurnal animals spending most of their day searching for food, they spend most of their lives in trees(99% of their time) traveling from branch to branch by climbing, clambering, and brachiating. Adult males are mostly arboreal and will come to the ground in search of food. They also use tools to get food, scratch themselves, and for entertainment reasons. Orangutans are known as escape artists in captivity useing any number of tools and tricks to get out of their cages.

      Orangutans are highly endangered. There is only an estimate of about 50,000-60,000

left in the wild, and only 7,500 of those are Sumatrans. They are endangered due to logging, mining, farming, and the spread of palm oil plantations, as well as poachers killing them for the bush meat and illeagle laboratry / pet trade. Because of all these reasons, orangutans populations are forced into ever decreasing habitat ranges in which they cannot support themselves. . There are many laws in Asia to protect

them but they are hard to enforcedue to lack of funding and interest. At the rate of population depletion experts predict the extinction of the wild Sumatran Orangutan in as little as 10 years.