The 3 Species Of Orangutans

Bornean orangutan is a species of orangutan native to the island of Borneo. Image credit: Milan Zygmunt/
  • Originally considered to be one species belonging to genus Pongo, orangutans were divided into two species in 1996.
  • A third species of orangutan was identified in 2017.
  • All three species of orangutans are critically endangered.

Orangutan, meaning "man of the forest" in Malay, is the world's largest arboreal mammal. Orangutans are great apes sharing 96.4% of genes with humans and are highly intelligent. Once found throughout South China and Southeast Asia, currently the range of these animals is highly restricted to the rainforests of Borneo and Sumatra. Originally considered to be one species belonging to genus Pongo, orangutans were divided into two species in 1996 - the Bornean orangutan (Pongo pygmaeus) and the Sumatran orangutan (Pongo abelii). A third species of orangutan was identified in 2017 and named the Tapanuli orangutan (Pongo tapanuliensis). These three species of orangutans are discussed in further details below:

Bornean Orangutan

Bornean orangutan mother and cub in the Bornean rainforest of Indonesia. Image credit: Sergey Uryadnikov/
  • Scientific Name: Pongo pygmaeus
  • Subspecies: P. p. pygmaeus, P. p. wurmbii, and P. p. morio
  • Range: Island of Borneo
  • Conservation status: Critically endangered

The Bornean orangutan (Pongo pygmaeus) lives on the island of Borneo. It is a highly intelligent species that displays the use of advanced tools and cultural patterns. It is the world’s third heaviest living primate following two species of gorillas and is the biggest truly arboreal living species today. The Bornean orangutans inhabit the tropical and subtropical moist broadleaf forests in the lowlands of the region. The animals live in the canopy region of these forests and move from one tree to another in search of food. Fruits, seeds, leaves, bird’s eggs, flowers, etc., are part of the diet of the Bornean orangutan. 

The Bornean orangutan is greater in number than their Sumatran and Tapanuli counterparts. About 54,500 individuals of this species are left in the wild. However, despite this number, one cannot deny the fact that these orangutans are also quickly disappearing. The bushmeat trade, illegal pet trade, and habitat destruction are the major factors behind the disappearance of these animals. The animals are thus also classified as critically endangered by the IUCN.

The Bornean orangutan has three subspecies. The Northwest Bornean orangutan (P. p. pygmaeus) is found in northern West Kalimantan (Indonesia) and Sarawak (Malaysia). The Central Bornean orangutan (P. p. wurmbii) lives in Central Kalimantan and Southern West Kalimantan in Indonesia. The third subspecies is the Northeast Bornean orangutan (P. p. morio) which is found in Sabah (Malaysia) and East Kalimantan (Indonesia).

Sumatran Orangutan

A Sumatran Orangutan at Bukit Lawang, North Sumatra, Indonesia. Image credit: DH Saragih/
  • Scientific Name: Pongo abelii
  • Subspecies: None
  • Range: Island of Sumatra
  • Conservation status: Critically endangered

One of the three orangutan species, the Sumatran orangutan (Pongo abelii) is found exclusively in Indonesia’s Sumatra island. The males of this species are about 1.4 feet tall, and females are about 90 cm tall. These animals have longer faces than their Bornean counterparts. They also have a paler red colored and longer hair than the Bornean species. The Sumatran orangutans are more arboreal and frugivorous than the Bornean ones. However, they also consume bird eggs and small vertebrates. The orangutans are also quite adept at using tools for hunting. They are also more social than the Bornean species.

As of 2015, only about 7,000 Sumatran orangutans live in the wild. Thus, they are classified as critically endangered species by the IUCN. Captive breeding programs of these animals are being carried out, but there is the fear that these captive animals might lose the qualities to live in the wild once released. Logging in the habitat of the Sumatran orangutans, conversion of forest land to plantations, palm oil cultivation, hunting by locals for food, etc., are the major threats faced by these orangutans.

Tapanuli Orangutan

  • Scientific Name: Pongo tapanuliensis
  • Subspecies: None
  • Range: South Tapanuli region of Sumatra island
  • Conservation status: Critically endangered

The Tapanuli orangutan (Pongo tapanuliensis), is the newest described species of orangutans. Only described in 2017, Tapanuli orangutans inhabit the South Tapanuli region of Sumatra island in Indonesia. Tapanuli orangutans spread in a region of 1,000 square kilometers in the tropical and subtropical watery forests south of Sumatra's Lake Toba. The estimated total number of Tapanuli orangutans is less than 800, making the species incredibly rare.

Though the Bornean orangutans are close to the Tapanuli orangutan in features, the Tapanuli orangutan have flattened faces, smaller head sizes, as well as frizzier hair on their bodies. Of equal note, they have a unique diet, which may include items like conifer cones and caterpillars. In addition, the ‘long call’ of male Tapanuli orangutans differs from that of the other two species. Interestingly, female Tapanuli orangutans sport beards while their male counterparts have a pronounced moustache. Tapanuli orangutans also have a relatively large canine tooth as compared to the other two types of orangutans.

Orangutans And Humans

The native people of Sumatra and Borneo always lived in perfect harmony with these orangutans. While some communities would hunt these creatures for food, others would fiercely protect them as part of their culture. There are several folktales in the region concentrating on the interaction of humans and orangutans. Some of these even claim that female orangutans are capable of seducing hunters and also mention orangutans kidnapping humans for mating.

The true demise of the orangutans began with the discovery of these animals by European explorers in the 17th century. The animals were then extensively hunted and exploited. Habitat destruction started in the later centuries as waves of modernization and development spread across Sumatra and Borneo. Large tracts of rainforests inhabited by these animals were cut down and destroyed to make way for crop fields and extensive plantations. Birutė Galdikas, a Canadian conservationist, was one of the main figures who realized the need to protect the orangutans and stood for the rights of these animals. Her efforts at conservation helped in capturing world attention to these fast disappearing species and governments were forced to launch efforts to conserve the orangutans. 

Conservation Of Orangutans

A group of young orangutans socializing. Image credit: Tristan Tan/

All three species of orangutans mentioned above are critically endangered. The population of the Bornean orangutans have drastically declined by 60% in the last 60 years and might decline further if strict conservation measures are not adopted. The range of these animals have drastically reduced to patchy sections on the island and the species have been eliminated completely from large areas where they once lived. The Sabangau River population is the biggest surviving population of this species. A similar fate has met the Sumatran orangutan whose population have declined by 80% in the past 75 years. Most of the population is restricted to a small range in the Leuser ecosystem. As mentioned previously, the estimated total number of Tapanuli orangutans is less than 800.

A significant number of national and international organizations are working to rescue and rehabilitate the orangutans. The Borneo Orangutan Survival Foundation, the World Wildlife Fund, Orangutan Land Trust, etc., are some of the organizations trying to ensure a safe future for these animals.


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