Species: Pongo pygmaeus
Fossil evidence suggests that orangutans were once widely distributed in South East Asia, but Bornean orangutan is today restricted solely to the island of Borneo with the largest population located in Kalimantan, the Indonesian part of the island.
Bornean orangutans are only found in forested areas, but can be found in various types of forests, from low-level swamps to mountainous areas 1500 m in elevation. They can be found at various heights in the trees. They may move large distances to find trees bearing fruit.
Orangutan means 'person of the forest' and this Asian ape is indeed truly a tree-dweller. Borneon Orangutans have distinctive body shapes with very long arms that may reach up to 2 meters in length. They have a thin, shaggy coat that is reddish brown in color and grasping hands and feet.
They are highly sexually dimorphic, with adult males being distinguished by their large size, throat pouch and flanges on either side of the face, known as cheek pads, which are made up of deposits of subcutaneous fat bound by connective tissue. These cheek pads continue growing for much of an adult male's life.Head and body length is about 100 - 150 cm.
Giza Zoo has 3 Borneon Orangutan came from Al Ain Park. Tee tee, the female, weighs 92 kg, Fatouta, her husband, is 146 kg, and their friend Bangu is 165 kg.
Bornean orangutans may reach the age of 60 years in captivity, although the lifespan in the wild is of about 35 to 40 years.
Bornean orangutan diet consists mainly of fruit, especially figs. Various species of figs ripen at different times in the year, and the movement pattern of the animals can largely be explained by their following this process.
Bornean orangutans will also eat other kinds of vegetation, such as leaves, bark, buds, and flowers. They will also occasionally eat mineral-rich soil, insects, and possibly eggs and small vertebrates. They drink by reaching into tree holes and lapping water from their hands.
Bornean orangutans do not form large social groups. Individuals usually travel alone or in small groups consisting of 2 females, their dependent young, and occasionally an adult male. Generally males and females come together only to mate, and otherwise do not associate with one another. Males' home ranges are often 2 to 6 sq. km. in size, and overlap the ranges of several females but not usually those of other males, toward whom they are aggressive.
Bornean orangutans are active during the day (diurnal) and are almost exclusively arboreal. They can be found at various levels in the trees. They usually walk along and swing from branches, descend to the ground only if they cannot move between trees via the branches. Each night they construct, using vegetation, a platform-style nest 40 to 60 feet high in a tree on which they sleep. They may descend briefly to the forest floor to obtain branches for building these nests. They cannot swim.
| Bangu, Tee Tee, and Fatouta with Dr. Saad the Animal Health Manager, Al Ain Zoo.|
Gestation lasts from 233 to 263 days, and typically one offspring is born, although twinning sometimes occurs. Weaning occurs around 42 months. The infant spends its first two to three years being carried constantly and will still remain close to the mother for at least another three years. Female may give birth every 3 to 4 years, but Orangutans are known as the slowest breeding of all mammal species, with an inter-birth interval of approximately 8 years.
Females reach sexual maturity at 7 years of age, by which time females have attained their adult size. But tend to only give birth after they reach 15 years of age. Males reach their sexual maturity at 10 years of age, and do not have the physical and social maturity required for successful mating until about 14 years of age.
Female Bornean orangutans have an estrous cycle about 30 days in length with ovulation occurring around the 15th day. This species does not have genital swelling during estrous, and females have a light menstrual flow lasting 3 or 4 days.
Bornean orangutans are polygynous. Although mainly solitary, the home ranges of males overlap those of females. On the rare occasions that the females within their home ranges are sexually receptive, dominant males will mate with them. Younger, smaller males, which are not able to maintain home ranges of their own, often wander alone through the forests. These males may also mate with females, although such copulations are generally forced, and appear to occur as the opportunity arises, not because the female is sexually receptive or fertile.
IUCN Red List: Endangered.
Bornean orangutans populations have been declining in both range and numbers for many years. The species is now in danger of becoming extinct. Humans have a long history of hunting this particular primate for various reasons, more recently for exhibition in zoos. It is estimated that at least 3 orangutans die for each one that is successfully captured and transported. They are now protected by law, but poaching still occurs. The population is currently being further devastated by the destruction of their habitat through deforestation, mainly for logging purposes.