Orangutan information

Introduction

Once found throughout much of Southeast Asia, the red ape now only survives in small populations in increasingly fragmented patches of forest on the islands of Borneo and Sumatra.

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There are three species of orangutan: Pongo abelii (Sumatran orangutan) and Pongo tapanuliensis (Tapanuli orangutan) in Sumatra and Pongo pygmaeus (Bornean orangutan) in Borneo.



Within Borneo, Pongo pygmaeus is divided into three further subspecies: Pongo pygmaeus morio in Sabah and East Kalimantan, Pongo pygmaeus wurmbii in central and southern areas, and Pongo pygmaeus pygmaeus in Sarawak and the North West. It is estimated that there is a Bornean population of approximately 105,000 individuals which is projected to decline to 47,000 individuals by 2025. Comprehensive aerial surveys in the early 2000s provided an estimate of 11,000 individuals for the entire state of Sabah.

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In July 2016 the IUCN reclassified the status of the Bornean Orangutan to Critically Endangered. This means they are close to becoming extinct in the wild.

Orangutans are essentially solitary animals. They can live up to 40 years in the wild and often longer in captivity. Females occupy relatively small ranges up to 3 square kilometres depending on food distribution. Female orangutans and their young may gather in one area if there is an abundance of food but they do not live together in social groups. Dominant males have territories covering several kilometres which can include the territories of several females. A fully flanged dominant male will attract local females for mating with his distinctive 'long call' which can be heard across the forest.

The adult males are much larger than the females. The average female adult weight is around 40kg, roughly the size of an eleven year old child, while males can be double that.


The gestation period for orangutans is around eight and a half months. The infants are weaned when they are 3 to 4 years old but they will spend at another 5 years with their mother to fully gain the necessary skills and knowledge to survive independently in the forest. A female may have just two or three babies in her lifetime which means orangutans as a species struggle to repopulate as their numbers decline.


Living & feeding

Orangutans live most of their lives high up in the tree canopy and their bodies are perfectly evolved for this. While they have no tails and do not jump, their massive arm spans, incredible strength, elongated and curved fingers, and their gripping feet mean that they’re easily able to move around in the treetops by reaching, swinging, or climbing from tree to tree. Swinging through the canopy hand over hand helps to give orangutans such great arm strength, and this form of locomotion is called 'brachiation'. Each night they make make nests to sleep in by breaking and folding branches high in the treetops. They often make these more comfortable by loading them with lots of leaves to act as their mattress and pillow.

An orangutan will typically spend around half of its day finding food. They are mainly frugivores, which means that they generally prefer to eat forest fruits whenever they are available. When the forest is in low fruiting season however, they’ll increase the amount of leaves, barks, piths and insects in their diets. As a species overall, orangutans are known to have eaten around 400 different plant species. This also helps to explain why they have also evolved such great intelligence as they commit to memory an incredibly detailed map of the forest, and document where and when certain trees bear fruit during the year throughout their large home ranges.

A recent study by our conservation partner, Borneo Nature Foundation, found that orangutans, like humans, use medicinal plants to treat joint and muscle inflammation.

Emotion and Intelligence

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Given that orangutans share nearly 97% of their DNA with humans, it is unsurprising that we can see similarities in behavioural traits such as emotion and intelligence. Orangutans are roughly as intelligent as a three/four year old human child. The clever apes are capable of constructing and using tools, and have also been witnessed by field researchers washing their clothing, bathing them-selves, brushing their teeth and even using damp rags to cool themselves down. This learned behaviour indicates orangutans are capable of self-awareness, planning and imitation. Their high levels of emotional intelligence add even more reason to work towards the conservation and welfare of this incredible, sentient creature.

Why do they need our help?

Asia’s only Great Ape species has been in decline over recent decades for a variety of reasons, but the loss of their preferred lowland habitat is the most significant factor. Forest degradation, often a precursor to deforestation, starts with the establishment of a network of logging roads, which open up vast tracts of previously inaccessible forest for timber extraction and mining. Once valuable wood stocks and minerals have been exhausted, forests can be cleared to make way for industrial oil palm, acacia and rubber plantations.

Indonesia and Malaysia, which is home to orangutans, produce 90% of the world’s palm oil. Palm oil is so popular because it has the highest per hectare yield of all edible oils, as such more than half of all supermarket products now contain it. Poor land use has also led to the widespread fragmentation of remaining natural forests, which leaves little pockets of land with no connecting forested corridors for the apes to travel along. This isolation of wildlife populations is a major factor in creating conditions which cause local extinctions due to reduced gene flow and foraging opportunities, and a general increase in competition for remaining resources.


Deforestation

Forest fires, usually started by plantation companies to clear land, can also burn large areas of forest, which took thousands of years to form, in just a few hours, destroying habitat for orangutans and countless other species. As the rate of deforestation and fire has increased, so have human-orangutan conflicts, as starving, displaced animals raid plantations and village small holdings in search of food, where they are often killed.

Other immediate threats include poaching and killing of orangutans for bush meat, for their supposed medicinal value and/or as a means of crop protection. Many of the orphaned orangutans that are rescued are found alone without their mothers, which indicates the mother has been killed and the baby left to fend for itself, which inevitably will lead to death. Other youngsters are taken and kept or sold illegally as pets, kept in appalling conditions deprived of a life in the wild. Some are illegally exported out of the country and kept in private zoos or are supplied to the 'entertainment' industry to perform in shows.

The combined impacts of the above threats equate to an 86% population reduction of the Bornean orangutan between 1973 and 2025, which means they are now listed as Critically Endangered by the International Union for Conservation of Nature (IUCN). They are a species close to extinction and they need our help. Find out here how you can help.

THEIR LIVES IN YOUR HANDS !