Bornean orangutan

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Bornean orangutan
Bornean orangutan (Pongo pygmaeus) in Tanjung Puting National Park

Bornean orangutan ( Pongo pygmaeus ) in Tanjung Puting National Park

Systematics
without rank: Old World Monkey (Catarrhini)
Superfamily : Human (Hominoidea)
Family : Apes (Hominidae)
Subfamily : Ponginae
Genre : Orangutans ( pongo )
Type : Bornean orangutan
Scientific name
Pongo pygmaeus
( Linnaeus , 1760)

The Bornean orangutan ( Pongo pygmaeus ) is a great ape . Together with the Sumatran orangutan and the Tapanuli orangutan described in 2017, it forms the genus of orangutans . It is endemic to Borneo .

features

Skull ( Museum Wiesbaden Collection )

Bornean orangutans share with their Sumatran relatives a physique that has been adapted to a tree-dwelling way of life: the arms are very long, the hands hook-shaped, the thumb short and located close to the wrist, the legs short and flexible and the feet hand-like. However, they are a bit sturdier and heavier than the Sumatran orangutans. Further differences lie in the longer fur , which is darker and brownish in color, and in the cheek bulges, especially of the older males: These grow outward and are almost hairless. In addition, the beard is usually shorter and the throat pouch of the older males larger. With up to 90 kilograms, the males are significantly heavier than the females, which can reach up to 50 kilograms.

Way of life

Borneo orangutans are diurnal forest dwellers; when they sleep they build a nest of leaves that is usually only used once. They slowly climb with all four limbs or swing on the branches. Males in particular also make forays on the ground - significantly more than their Sumatran relatives, which could be due to the lack of tigers on Borneo.

They are mostly found alone and more solitary than Sumatran orangutans. Males and females try to establish fixed territories, but younger animals in particular spend their lives as “hikers” who constantly roam without territory. They use tools much less frequently than their Sumatran relatives.

Borneo orangutans are herbivores that feed primarily on fruits, but also on leaves, young shoots and tree bark.

Threat and protection

Young orangutan in a station in Borneo

The Bornean orangutan is an endangered species. The main reason for this is the loss of its habitat: the forests are being cleared to a large extent for wood production or for the establishment of agricultural land (e.g. for palm oil ). Their range is therefore greatly reduced and fragmented. In addition, there is hunting and the illegal trade in young animals that are kept as pets. These factors are exacerbated by the slow reproduction rate of the animals: a female only gives birth to a young every four to eight years.

Overall, however, the species is even more common than the Sumatran orangutan. Estimates of the total population are difficult and range from 15,000 to 44,000 animals. The IUCN has listed the species as critically endangered since 2016 .

The Borneo Orangutan Survival Foundation , BOS for short, maintains two reintroduction centers, Wanariset in East and Nyaru Menteng in Central Kalimantan on Borneo, as well as the reforestation project Samboja Lestari , in the near-natural rainforest as a habitat for up to 2000 orangutans and other species native to Borneo should arise. Further protected areas and centers are located in the National Parks Gunung-Palung , Tanjung-Puting and Kutai (all Indonesian part) as well as in the Sepilok Rehabilitation Center near Sandakan and the Danum Valley Conservation Area in Malaysia. In the 1990s, the Borneo Orangutan Survival Foundation released 350 orangutans into the Meratus sanctuary. There the organizations fans for nature, Faszination Regenwald e. V./Ulmer initiative to save the orangutans and the Borneo orangutan aid a joint protection project.

Systematics

In the past, the two orangutan populations from Sumatra and Borneo were grouped together as subspecies of one species, but today they are viewed as two separate species due to differences in physique and lifestyle. The Bornean orangutan is divided into two or three subspecies: Pongo pygmaeus pygmaeus in the northwest of the island, P. p. morio in the northeast and east (this subspecies is sometimes grouped with pygmaeus ) and P. p. wurmbii in the southwest. The subspecies differ in their skull structure.

literature

Web links

Commons : Bornean Orangutan  - Collection of images, videos and audio files