• STATUS: Critically Endangered
  • POPULATION: About 104,700
  • SCIENTIFIC NAME: Pongo pygmaeus
  • HEIGHT: 3.3 – 4.6 feet
  • WEIGHT: 66–220 pounds
  • HABITATS: Lowland rainforests and tropical, swamp and mountain forests

Over the last 60 years, Bornean orangutan numbers have fallen by more than 50%, and the species’ habitat has been reduced by at least 55% in the last 20 years.

The Bornean orangutan has a wider face and shorter beard than the Sumatran orangutan, as well as being slightly darker in color. There are three subspecies, each of which is found in distinct sections of the island:

The Northwest Bornean orangutan subspecies is the most endangered. Logging and hunting have severely harmed its habitat, and only around 1,500 individuals survive. Many habitat patches are small and fragmented in the area.Northeast Bornean orangutans are the smallest and can be found as far as the Mahakam River in Sabah and eastern Kalimantan.With at least 35,000 individuals, Central Bornean orangutans are the most numerous subspecies.

Bornean Orangutan.
Bornean Orangutan

Why They Matter

Orangutans are important for seed dispersion, which keeps forests healthy. Their food includes more than 500 plant species.


Human activities have caused orangutan numbers and distribution to rapidly drop since the middle of the twentieth century. Hunting, unsustainable and frequently illegal logging, mining, and forest conversion to farmland are among them. The 1997-98 forest fires in Kalimantan, which killed up to 8,000 orangutans, were a particularly tragic event.

Illegal Wildlife Trade

The pet trade for young orangutans is thriving, with each animal bringing several hundred dollars in major markets on adjacent islands. According to studies, 200-500 orangutans from Indonesian Borneo are sold as pets each year. Because orangutans have such a poor reproduction rate, this poses a serious threat to natural populations. Orangutan parts are also traded in Kalimantan, with orangutan skulls bringing up to $70 in cities.

Bornean Orangutan.

Conflict With Humans

When orangutans enter agricultural areas, such as oil palm farms, and destroy crops, they are occasionally shot in reprisal. This is especially true during times of adversity, when orangutans cannot find the food they require in the wild.