There are two species of orangutan and both are endangered. The Sumatran orangutan Pongo abelii is the most critically endangered of the two, and is given the status 'Critically Endangered' by the IUCN Red List of Threatened Species. The other orangutan species, the Bornean orangutan Pongo pygmaeus, is slightly less endangered, but is nonetheless considered 'Endangered' by the IUCN.
Since the two species belong to two distinct districts, namely Sumatra and Borneo, this article will deal with the issues impacting on their well-being separately.
The Sumatran orangutan lives in the forests of the Indonesian island of Sumatra. They rarely travel on the ground and are almost entirely arboreal. They eat fruit, leaves, and insects, and occasionally meat. Over the last 75 years there has been an 80% decline in their numbers, leading to their classification as 'Critically Endangered'.
The last reliable estimate of their numbers was given as 7,300; however, this was taken from data collected prior to the 2004 tsunami, an event which has placed considerable pressure on the logging industry, which is a major driver of arboreal habitat loss on the island.
Other threats to the Sumatran orangutan include changes in land cover from forest to agricultural land and palm oil estates, habitat fragmentation by roads (including a proposed new road network), and they are occasionally hunted for food by humans.
Orangutans are extremely intelligent, forming complex social relationships and networks, and there is evidence of both tool-use (for example, for insect-and seed-extraction) and linguistic capabilities (such as the use of signs) among them. Studies into orangutan tool-use have suggested that there is a cultural element to their use, such as the employment of leaves to amplify sounds made with the lips.
Efforts to protect both species of orangutan have so far focused on legislation: they are protected under both Malaysian and Indonesian law. In Sumatra, the Leuser Ecosystem conservation area supports around 75% of the remaining population of orangutans, while in Borneo there is a network of protected forests, although here, the majority of the population exists outside of these areas. However, despite current efforts to conserve them, both species of orangutan remain in decline, and if the trends of their dwindling numbers continue, they face extinction.
If you want to get involved with their conservation, there are many organisations working to protect the orangutan, with some of the largest being the Borneo Orangutan Survival Foundation, the Orangutan Conservancy, and the Orangutan Land Trust.
This article was written in memory of Sir Terry Pratchett.
Image credits: WWF and Wikimedia.
