Have a question about orangutans? Maybe it’s asked frequently.
Orangutans live in lowland forests on the islands of Sumatra and Borneo, within Indonesia and Malaysia. These are the ONLY places in the world where orangutans are found in the wild. Orangutans live mainly in the trees and forest canopy, only occasionally coming down to the forest floor.
Orangutans are classed as omnivores, meaning they eat both plant and animal matter, but the majority of their diet comes from plants. Orangutans are incredibly versatile and have been observed feeding on more than 2,000 different plant species. Most of their foraging time is spent feeding on fruit, but they also eat leaf shoots, leaves, bark, flowers, fungi, pith, insects, honey, and the occasional egg. Rare reports even describe orangutans eating small mammals.
While it varies according to season and location, orangutans can spend up to 60% of their waking hours feeding on different foods. They spend about 10% of their day travelling through the jungle, often in search of new food sources. The remaining 30% of their time is filled with a range of activities, from resting and grooming to playing and engaging in other social activities.
In the wild, their average lifespan is 35-40 years, but individuals have been estimated to live into their 50s. In captivity, the current record for longest Bornean orangutan lifespan belongs to ‘Gypsy,’ who passed away at the estimated age of 62 at the Tama Zoological Park in Tokyo, Japan.
Orangutans have been recorded making more than 30 different vocalisations! While the purpose of many of these calls currently eludes modern scientists, several of the most common vocalisations are well described. Infants have been known to cry like human babies, and juvenile orangutans can cry and scream when they ‘throw tantrums’. Orangutans of all ages and sexes produce a ‘kiss-squeak’ in response to discomfort with a given situation in order to communicate their alarm. The most iconic of all orangutan vocalizations is the ‘long call’. These repetitive, low frequency calls are only produced by mature, flanged males, and can be heard from over 2 km away!
An infant orangutan can weigh as little as 1 kg at birth. This changes rapidly, as adult females can grow to weigh between 30-45 kg and males can weigh anywhere from 80 kg to more than 120 kg!
With fully mature males being double the size of females, orangutans exhibit one of the highest degrees of sexual dimorphism in primates! In addition to the difference in size, the faces of the sexes differ dramatically. Fully mature, male orangutans grow longer hair and develop a throat pouch and wide cheek pads, called flanges. The size of these impressive flanges varies among individuals based on their hormones and place in the greater dominance hierarchy!
After approximately 8.5 months gestation, a single infant is usually born. However, there have been rare instances when twins have been recorded! Once an orangutan mother gives birth, on average it will be another 8 years until she births another baby. This means that orangutans have the longest interbirth interval of any mammal, including humans!
Orangutan infants stay with their mothers long past infancy as immature orangutans will often live with their mothers until they are about eight years old. They receive breast milk for the first three years of their lives, and also learn to eat other foods by mimicking their mothers. This long period of dependence is indicative of the need to learn everything about survival in the forest from their mothers.
No. Classed as semi-solitary animals, adult orangutans spend most of the time on their own, with the exception of mothers and children who stay together for about eight years. Additionally, mothers and other related females have been known to gather briefly during times of high food availability and the immature orangutans will play together.
Female orangutans reach sexual maturity around 10-15 years of age. While they typically give birth to their first offspring in this age range in the wild, there is evidence to suggest this occurs earlier in captive individuals. Male orangutans experience what is known as bimodal physical development. The males will initially reach sexual maturity around 10-12 years old. Then starting from 15 years old, all the way into the early 20s, males will start to develop secondary sexual characteristics that include increased body size, longer hair, a throat pouch, and cheek pads.
Orangutans don’t build houses. Instead, they construct new nests each night in which to sleep.
Orangutans sleep in their nests, usually a new one made in the evening. Nests are woven in branches of trees using broken branches and leaves. They are often very well-crafted, like a large basket, and can sometimes be more than a metre wide. Orangutans also build nests in the daytime to rest and play in, and a mother with a young infant might build two or three nests a day. Expectant mothers also use nests to give birth in.
Normally, no. But, sometimes in captivity they can become aggressive as a result of how they have been treated. They are significantly stronger than humans, with two strong hands and feet, and an incredibly hard bite. Orangutans are usually very peaceful animals. If adult males meet one another, they initially try to avoid fighting by exchanging threatening gestures instead and will only resort to fighting when this fails.
Yes, of which HUMANS are the most dangerous! Other predators include the clouded leopard, Sumatran tiger, crocodiles, and snakes.
Our orangutan rehabilitation centres were set up to accommodate rescued and confiscated orangutans, many of whom had been kept illegally as pets. The aim is to guide and teach them the skills and behaviours they will need to return to the wild and thrive. Many orangutans have already been successfully rehabilitated and released back to natural habitats.
Now, this is a complicated question! But, in short - we are destroying their forest homes! Second, they reproduce very slowly, with a female typically only giving birth every eight years in the wild. Third, humans hunt orangutans for meat and to capture young infants for the illegal pet trade. Read more about ‘threats to orangutans’ here.