Orangutans are arguably the most intelligent of the great apes and one of our closest relatives. However, because of the ongoing destruction of the remaining rain-forests, they are on the brink of extinction.
The name orangutan is of Malayan origin and means “man – or more correctly, ‘person’ – of the forest”. They live only in Southeast Asia on the islands of Borneo and Sumatra, mostly in Indonesia, but also in the Malaysian states of Sabah and Sarawak on Borneo. Orangutans are currently divided into two distinct species: the Bornean orangutan (Pongo pygmaeus) and the Sumatran orangutan (Pongo abelii). Both species are on the IUCN Red List of Threatened Species, a list of the world’s most endangered species that is kept and updated by the World Conservation Union, IUCN. The IUCN red list recognises Bornean orangutans as ‘Endangered’, with an estimated remaining wild population of around 54,000, whilst the Sumatran orangutan is listed as ‘Critically Endangered’ with only around 14,613 individuals left. Indeed, the Sumatran orangutan is considered one of the world’s most endangered primate species!
Interestingly, recent studies of orangutan DNA suggest that within Sumatra, the orangutans may actually comprise two separate species too. There is mounting evidence that the last remaining wild orangutan population to the south of Lake Toba, namely what is known as the Batang Toru population, may be the only surviving population from the original, ancestral form of the orangutan. The data is suggesting that all orangutans to the north of Lake Toba, and also all the orangutans in Borneo, may actually be descended from an older population, that lived in central and southern Sumatra, but which is now extinct except for a small forest area near the Batang Toru river. If these early findings are confirmed, it will greatly emphasise the importance of conserving the Batang Toru forests and their orangutans. Scientists are even discussing whether or not the Batang Toru orangutans should be regarding as an entirely new orangutan species!
Like humans, all the great apes are extremely intelligent. Orangutans also share 96,7% of our own DNA. They recognize themselves in the mirror, learn from and teach each other new skills, and they have also been shown to take another individual’s perspective, meaning they are able to see a situation through another’s eyes. Scientists have even taught them communication skills, such as human sign language and the use of computer touch-screens. In zoos, orangutans are well known – and sometimes feared too – as the most adept tool users of all the animals, including the other apes, and the best escape artists too!