Bornean Orangutan

Orangutans mainly eat fruits, leaves, bark, flowers, and insects. The fruit in the wild is nutritionally similar to vegetables; wild fruits are much lower in sugar than what we have in the US. They spend a lot of time moving through the trees to find food. Sometimes, they can easily find high-calorie foods that let them eat as much as they want without traveling far. However, most of the time, the food they find is lower in calories, so they have to travel farther to get enough to meet their nutritional needs.

At the Zoo, orangutans are offered specially formulated leaf-eater biscuits, leafy greens, and a variety of fruits and vegetables.

Bornean Orangutans live on the island of Borneo in areas governed by Malaysia and Indonesia.

Bornean orangutans are found more often in low forests than in higher areas. They like areas that flood and peat swamps because these places grow more fruit for them to eat. Since orangutans live most of their lives high up in trees, they depend on these thick and rich forests to survive.

The only predator of Bornean orangutans is humans.

Since these orangutans spend most of their lives in trees, their populations are greatly affected by habitat destruction caused by palm oil plantations, farming, and logging. Forest fires, which often happen during land-clearing, can destroy large areas of forest. As their habitat shrinks, orangutans are forced into smaller, fragmented areas.
In addition to habitat loss, Bornean orangutans also face dangers from hunting for their meat and the illegal capture of baby orangutans to sell as pets.

Bornean orangutans are known for their orange-red hair and long arms, which help them move through the forest canopy. Unlike many other primates, they do not swing from branch to branch because of their larger size. Instead, they move more slowly and carefully, using both their hands and feet to grasp tree limbs. Their long hair and coloring help them camouflage in the tree tops.

One unique feature of Bornean orangutans is that they have two different forms of mature males, known as "bimaturism." Some males develop large cheek pads called "flanges," while others remain "unflanged." Flanged males can be twice the size of females and have a long coat of dark hair, a facial disk with flanges, and a throat sac that they use to make loud calls. These males usually have a well-defined territory that includes the areas where several females live and with whom they mate.

On the other hand, unflanged males are the same size as adult females. They do not have the unique characteristics of flanged males, do not make long calls, and are generally more tolerant of one another. Both types of males can have offspring. The change from unflanged to flanged male happens sometimes and is influenced by social interactions that are still not completely understood.

Dominant orangutan males usually have a well-defined territory that includes the areas where several females live. Younger males often cannot sustain a range of their own and wander throughout the forests, mating with females when they can. Female animals typically give birth to one baby after about 245 days of being pregnant. They become mature between the ages of 10 and 15 and usually have babies every seven to nine years.

The connection between mothers and their babies is very strong. Infants cling to their mother's fur and ride on her back. They are weaned around the age of three and can stay with their mothers until their early teens. During this time, they learn the skills needed to survive on their own. Young females usually stay close to their mothers, while young males wander the forest until they establish their own territories.

Orangutans have special throat pouches that let them make deep, echoing sounds in the forest. As male orangutans move around, they create different rumbling and howling calls to avoid running into each other. One of their main sounds is called the "long call." This call lasts one to two minutes and is only made by flanged males; it can be heard from over a mile away. When they are upset, orangutans use sounds like kiss-squeaks and belching. They also use facial expressions and body language to communicate their feelings.

Orangutans are considered semi-social, which means they often like to be alone compared to other great apes. While male and female ranges can overlap, it's uncommon to see male orangutans together.

These animals are great at moving through the treetops, but their way of moving looks different from that of other tree-dwelling apes because they are larger. Orangutans are also very skilled at building nests for resting. These nests provide a cozy place to sleep at night and are made from materials they find in their surroundings, like leafy branches.

Orangutans have been seen using tools to help with everyday tasks, and mothers pass these skills on to their young. For instance, they use sticks to get termites and honey, and they use large leaves as umbrellas when it rains.