So far in my blog I have talked about the threats to orangutans and about our work to save them and their habitat. In my next few posts I thought it might be an idea to tell you more about orangutans, why they are special and why saving them is so important. Some of you, I'm sure, already know a lot about orangutans so apologies if there's nothing new. For those of you who don't, I hope you will enjoy learning about one of your close relatives!! The orangutan is the only great ape found outside of Africa. Historically the orangutan's range spread throughout Southeast Asia to Southern China but now orangutans are only found in isolated populations on the islands of Sumatra and Borneo. Click to see the current range of the Bornean and Sumatran orangutan.
They are classified as having two separate species, the Bornean Orangutan, Pongo pygmaeus, and the Sumatran Orangutan, Pongo abelii. Under the IUCN Red List of Threatened Species the Sumatran Orangutan is classified as critically endangered and the Bornean as endangered. The two species show slightly different physical characteristics and these are seen more obviously in the males. For example, Bornean orangutans are darker with shorter coarse hair and the males have wider cheek pads than the Sumatran.
Behavioural differences have also been observed, Sumatran orangutans are more frugivorous and there is more evidence of tool use. The difference between the species, whether it is habitat induced or local adaptations, has yet to be confirmed.
Wild orangutans have only been studied in depth since the 1970’s and since they have a life span of 45 years plus, documentation of an orangutan's full life span has yet to be completed. Long running studies are elemental to our understanding of orangutans. Their behaviour varies and some isolated populations display unique behaviour. Just over ten years ago it was discovered that wild orangutans regularly manufacture and use tools. In the area of Suaq Balimbing, Gunung Leuser National Park, in Sumatra, the orangutans had 54 different tools just for extracting insects.
What is obvious to anyone who has spent time observing orangutans is their striking individual personalities and the fact they are extremely intelligent. Their ability to imitate human behaviour seems limitless, so much so, that at Camp Leakey, in Tanjung Puting National Park, canoes have to be sunken to avoid them being stolen by orangutans. There are complex lock systems on external doors to try and prevent orangutans getting in, and these have to be updated fairly often as the orangutans eventually work them out!
Trying to break in!
Orangutans have learnt sign language. This skill has been learnt in their natural habitat and not just in laboratory conditions. At Camp Leakey, Dr Gary Shapiro taught sign language to an ex-captive orangutan called Princess. He observed Princess forming new words out of existing words that he had taught her.
Orangutans are culturally important to the indigenous people of Indonesia and Malaysia with many folktales told about them. In Malay and Indonesian orangutan means “person of the forest”, however there are also many local names that exist. Some Malays believe that male orangutans are ghosts and Dayak groups believe that orangutans don’t talk because otherwise they would be made to work!
Next time I will tell you about the orangutan’s life history and why this increases their vulnerability as a species.