Orang-utans and map reading

Our close cousin is an incredibly intelligent animal. Did you know that he keeps a map in his head, which tells him where the fruit trees are fruiting and when – even more difficult when you consider that in the resource-poor environment that is the rainforest, some trees only fruit once in four years!

The young Orang-utan spends the first five to seven years with mum, during which time he learns where the trees are and when they fruit building up his mind map. This is why it is not possible to rehabilitate an Orang-utan to the wild. Captive orang-utans were always babies when caught (by murdering mum) and brought up by people, thus not developing a mind map. In the rehabilitation centre at Bohorok, the orang-utan does go back into the forest, but for the rest of his life he will always come back for food hand-outs as his lack of knowledge fails him in finding food. And he lives a good forty to fifty years.

This is also why ‘sustainable logging’ is rubbish – it murders 60% of the Orang-utan in the forest, because it takes out some of the fruit trees – and there is no alternative in their map. They starve to death looking for another fruiting tree and waiting for their next one to ripen.

The orang-utan is a very tough, strong animal. Living in the trees as he does, he actually has four arms and no legs. The hunters go after babies to sell them as pets. They will need to shoot mum about ten times before she actually falls out of the tree, and she can still hang on with two broken arms.

The only good news is that in the Leuser ecosystem that is home to most of the remaining Sumatran Orang-utan, the local population knows this and reports to our rangers anybody who has an illegal baby orang-utan. There has only been one case so far this year, which is a BIG drop, so we are winning this war.

It’s too late for a lovely Orang-utan sub-species that lived near Sibolga in Sumatra. Dark red hair, long fingers, highly intelligent, none have been seen for many a year. But in Leuser we have 7,500 of the main Sumatran species, and there are another 600 to the north that we aim to bring into the reserve next year. They are safe. It is a different story in Borneo, where there may be 11,000 Orang-utan, but they are scattered and in small bits of forest, reduced to eating oil palm nuts.

These fractured populations are not really viable. A female Orang-utan has a baby about once every 5 to 7 years, and will have at most 7 in her lifetime, so populations grow very slowly.

How do you recognise an Orang-utan researcher? By the missing fingers…. Occasionally we have had to relocate Orang-utan. We would tranquillise the ape high in the tree with a dart gun. As he gets woozy and sleepy, being very smart he comes down to the ground, where we can throw a net over him. These nets have centimetre thick, heavy nylon cords, but he will still bite through them like cotton. And when the researcher thinks he is asleep, and can start taking his measurements and samples, he is often just awake enough to nip the nearest finger…

Find out more about the work Force for the Forest are doing in Sumatra, where we have saved 7,500 Orang-utan in 25,000 square kilometres of forest, the last remnant of the great expanse that coated SE Asia.