The Sumatran Orangutan Faces Large-scale Habitat Loss

By: Nicole Antonio & Sascha Bos  | 
Close-up of an adult orangutan with a baby organutan hugging her head from behind
This Sumatran orangutan mother looks overwhelmingly content with a baby on her neck. Manoj Shah / Getty Images

Key Takeaways

  • The Sumatran orangutan is critically endangered, with fewer than 14,000 individuals remaining due to habitat loss and illegal wildlife trade.
  • Deforestation for palm oil plantations and other agricultural activities has drastically reduced their natural habitat in Sumatra.
  • Conservation efforts include protected areas, reintroduction programs, anti-poaching initiatives and promoting sustainable palm oil production.

The Sumatran orangutan, scientifically named Pongo abelii, inhabits the lush rainforests of Sumatra. These arboreal primates, known as "persons of the forest" in Malay, are highly intelligent and share close genetic ties with humans.

Unfortunately, wild orangutans currently face the threat of extinction, as their population has drastically declined over the years.


In this comprehensive article, we will explore the unique characteristics of Sumatran orangutans, their habitats, the challenges they face and the conservation efforts being made to protect this critically endangered species.


Characteristics of Sumatran Orangutans

Size and Physical Description

Sumatran orangutans boast the title of largest arboreal primates on the planet, with adult males typically reaching heights of 4.5 to 6 feet (1.4 to 1.8 meters) and weighing between 110 and 200 pounds (50 to 90 kilograms). Some of the largest adult male orangutans have even been recorded weighing up to 250 pounds (113 kilograms).

Females, on the other hand, are generally smaller, standing at 3 to 4 feet tall (0.9 to 1.3 meters) and weighing between 66 and 110 pounds (30 to 50 kilograms). Wild sumatran orangutans tend to weigh less than orangutans in captivity due to the difference in food availability.


They have long, reddish-orange fur which is sparse and has a fine texture. It can be difficult to distinguish Sumatran orangutans from Bornean orangutans as they have similarly colored hair and closely related physical features.

Adaptations for Tree Dwelling

This tree species of orangutan has developed several adaptations that enable them to thrive in their tree-dwelling lifestyle. Their strong arms, which are roughly 50 percent longer than their legs, allow them to traverse among the trees with ease.

Their fingers and toes are long and strong, providing them with a firm grip on branches. These primates also possess opposable thumbs, helping them to use tools and extract embedded food.

Their feet are shared very similarly to their hands, meaning they can use the appendages interchangeably when navigating the forest canopy.

Social Behavior

Unlike other apes, Sumatran orangutans are mostly solitary, with males being loners. They communicate using dozens of vocalizations, including long calls that can be heard up to 1.2 miles (1.9 kilometers) away.

Female orangutans, however, bond with their young and care for them until the young orangutans can survive independently, about six or seven years.


Sumatran Orangutan Habitat and Distribution

Sumatran orangutans live in the tropical rainforests of Sumatra, an island located in Indonesia. Historically, they were distributed across the entire island and ink Java.

However, their range has significantly decreased, and they are now primarily found in the northern part of Sumatra, specifically in the provinces of North Sumatra and Aceh. Their habitat consists of tropical and subtropical moist broadleaf forests, which provide them with the necessary resources for survival.


Threats to Sumatran Orangutans

Habitat Loss and Deforestation

One of the biggest threats to the survival of Sumatran orangutans is habitat loss due to deforestation. The rapid expansion of oil palm plantations and other agricultural activities has resulted in the destruction of their natural habitat.

In the last two decades, there has been an 80 percent decline in the expanse of their habitat. This loss of habitat not only affects the orangutans but also endangers other species that rely on the same forests for survival.


Illegal Wildlife Trade and Hunting

Sumatran orangutans are also victims of illegal wildlife trade and hunting.

Despite legal protection, these primates are still captured from the wild and kept as pets or status symbols. The demand for infant orangutans as pets is particularly high.

Additionally, hunting for meat poses a serious threat to the Sumatran orangutan population. With females giving birth only once every eight years, their slow reproductive rate makes them highly vulnerable to even low levels of hunting.


Conservation Efforts

Protected Areas and Reintroduction Programs

Efforts are being made to protect the remaining populations of Sumatran orangutans. Several protected areas, such as Bukit Tigapuluh National Park, serve as havens for these primates.

Orangutans that have been confiscated from the illegal pet trade are being reintroduced to these protected areas, allowing them to reestablish their populations and contribute to their long-term viability.


Anti-poaching and Law Enforcement

Collaborative efforts between organizations like the World Wildlife Fund (WWF) and local authorities focus on anti-poaching initiatives and strict law enforcement to combat the illegal wildlife trade.

By cracking down on the trafficking of orangutans and implementing stronger penalties for offenders, these efforts aim to reduce the demand for orangutans as pets and protect their populations in the wild.

Sustainable Palm Oil Production

Given that oil palm plantations contribute significantly to habitat loss, there is a growing movement towards sustainable palm oil production.

Organizations like the Association of Zoos and Aquariums (AZA) advocate for environmentally sustainable practices and work with stakeholders in the palm oil industry to ensure responsible production that minimizes the impact on orangutan habitats.

We created this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.


Frequently Asked Questions

How do Sumatran orangutans communicate?
Sumatran orangutans use a variety of vocalizations, facial expressions and body language to communicate. They also use tools and objects in their environment to express themselves.
What are the main threats to Sumatran orangutans?
The main threats to Sumatran orangutans include deforestation for palm oil plantations, illegal logging and hunting. Conservation efforts focus on habitat protection and sustainable practices.