Conservation status

As recently as just one hundred years ago, there were an estimated quarter of a million Bornean and Sumatran orangutans across their Malaysian and Indonesian ranges. Today, it is estimated that there are about 12,000 individuals in Sumatra and 15,000 in Borneo (Rijksen & Meijaard 1999). At the current rate of loss, Asia's only great apes may be relegated to the annals of extinction within just a few decades. With life histories susceptible to negative impacts, even a female mortality rate of 1-2% can drive a local population into extinction.

Both species are under serious threat and both are protected by international conservation conventions (such as CITES - the Convention on International Trade in Endangered Species) and listed on conservation policy inventories, such as the IUCN Red List. Whilst the Sumatran orangutan is listed as being Critically Endangered on the IUCN Red List and Appendix I by CITES (preventing international trade), the Bornean orangutan is categorized as being Endangered on the IUCN Red List and again are under Appendix I on CITES. Despite such protection, it is estimated that in the ten years following the mid-1990s, the population of orangutans declined by between 30-50%. With some research placing predicted dates of extinction events within just a few decades, it is up to us now to save this gentle, enigmatic and fragile 'person of the forest' from extinction.

Threats to Bornean orangutans

With long life histories, characterized by long developmental periods and extended periods between pregnancies, populations of Bornean orangutans are susceptible to even minor changes in their environments. Although facing a range of threats; from persecution, disease transmission from humans and the effects of natural disasters, it is the anthropogenic (human) habitat associated threats which pose the most significant problems.  Deforestation and habitat fragmentation is proceeding at an unprecedented rate, with orangutans in Borneo and Sumatra literally losing their forest homes around them.
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Threat: Deforestation and Fragmentation

The single largest threat to populations of wild orangutans is the ongoing loss of their habitats. During the latter half of the twentieth century, Borneo lost more than 50% of its forest cover and more than 80% of the orangutan's habitat was destroyed. Badly managed timber extraction practices, along with the unsustainable conversion of forest to agricultural land continues to threaten these apes. Habitats within Borneo are faring far worse than those in Sumatra. As orangutans are wholly-reliant on trees for their survival, the destruction and fragmentation of forests has a devastating impact on their lives. Although fruiting trees are typically not targeted for timber production, they are often removed during the process. Additionally, the problems associated with commercial timber harvesting are exacerbated by illegal logging, where rather than following a mandated 30-40 year rest period before felling more trees in an area, logging generally continues until all of the commercially valuable timber has been extracted. This unsustainable extraction precludes the natural forest regeneration to occur, instead removing whole forest habitats and their ecosystems.

Oil palm plantations are an increasingly serious threat to orangutan habitat as land is completely converted from recovering logged forest habitats to what is known as a monoculture, where the ecosystem is dominated by a single species. Poor compliance with regulations, weak law enforcement and a weak legal environment all permit the problem of illegal timber harvesting and agricultural practices to continue.
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Threat: Bushmeat Hunting, Persecution and their Exploitation in the Pet Trade

The hunting of orangutans for meat and the associated capture of young apes for sale in the illegal pet trade both represent a further serious threat to the Bornean orangutans. Hunting and taking for the pet trade is often worst around areas where 'slash and burn' agricultural techniques are practiced and where large-scale timber extraction is occurring. Often, capturing and killing results from the orangutans being forced to leave their habitats in search of foods in and around fields and villages. Local people have little tolerance of orangutans desperately searching for food in 'human' areas and are quick to persecute them, either shooting, poisoning or snaring them. When an infant orangutan is found, the mother is killed and often discarded, to obtain the baby. Then, the young ape is smuggled out of Borneo to other places in South East Asia, such as Singapore, where they may then be transported far across the globe. It is estimated that 2-3 young are smuggled off Borneo each week. Their large size and slow deliberate movement makes orangutans easy targets for hunters.
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Threat: Natural Disasters

Climate change has played a significant role in the loss of Bornean orangutans and could have significant and long-lasting effects on both species of Asian great apes in the future. Following the 1997-98 El Niño event, a widespread drought led to the largest fire disaster ever observed, where literally millions of acres of habitat were lost to fire. These tropical forests, which are not usually susceptible to fires, were made vulnerable due to the impacts of the previously mentioned large scale logging. Whilst some of the fires were naturally occurring, many were started by local people - with over 12 million acres of forest being burned, thousands upon thousands of orangutans were killed.  Some researchers have estimated that population loss as a result of these fires could have been more than 30% of all Bornean orangutans.
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Threat: Disease Transmission

Orangutans are closely related to humans; splitting off from our lineage just 15 million years ago and sharing approximately 97% of our DNA material still. Consequently, although orangutans have evolved alongside us, they have developed different immune systems and with different 'native' diseases, meaning that they are naive to many of our diseases; so although they are genetically close enough to humans to catch many of our diseases, they have not evolved the necessary immune defences and consequently do not often fare well when they become ill as a result of catching our pathogens. Ethical and educational ape-based ecotourism is an important source of revenue for orangutan conservation organizations and an important means of promoting awareness for the species. These programmes often revolve around rescue and rehabilitation centres that care for and sometimes release orangutans that have been seized from illegal sources. Because of their close evolutionary and phylogenetic proximity to humans, great apes are susceptible to some human diseases. Diseases that have been known to affect great apes include paralytic poliomyelitis (polio), pneumonia, measles, and tuberculosis, with wild orangutans having had diagnoses including hepatitis A, B, C, D, and E, leptospirosis, cholera, malaria, HIV, and tuberculosis. If any of these zoonotic diseases are spread back into the wild, subsequently infecting wild (and naive) populations of orangutans, the consequences can be catastrophic. Ethical and sustainable eco-tourism can however be an effective and safe way of seeing great apes in their natural environments and as long as precautions are upheld such as maintaining safe minimum distances and not coming into close proximity if you feel unwell.
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Threat: Intrinsic Factors

The very nature of the orangutan itself makes it susceptible to the effects of many of these threats and problems, associated with climate change, habitat loss and negative anthropogenic factors. Once an orangutan habitat becomes fragmented and suffers any significant loss, the orangutans do not readily leave their forest home and are extremely reluctant to travel through open farmland and areas which have been cut down. This poor ability to disperse often prevents the orangutans from moving away from problematic areas, instead leaving them to face starvation, persecution or hunting. Also, female orangutans naturally reduce their reproductive ability as a result of poor food availability, meaning that as food becomes more scarce (through deforestation), fewer orangutans are being born into the already dwindling wild population. As orangutans already have a prolonged inter birth interval and young have a very long period of development into adulthood, the loss of even a few individuals consequently has disastrous impacts within the wider population.


Further Reading

For more information on orangutans; their biology and conservation, please follow these links:

The Great Apes Survival Project (GRASP):
www.unep.org/grasp/

ARKive:
http://www.arkive.org/

Photographs kindly provided by David Slater, Nick Bramley, STA

For information on deforestation and habitat loss, please CLICK HERE

Bornean orangutan (Pongo pygmaeus) orang-utan - ape facts conservation threats - Borneo Sabah Borneo South East Asia - Wildlife Holiday Responsible Travel