16.07.2008 - 18.07.2008
In Sabah, a short hour from Sandakan, is a large forest reserve, Sepilok, which covers over 4,000 hectares. Most is primary dipterocarp forest, while the section nearest the sea is mangrove forest. The reserve contains 450 species of trees, and ninety species of mammals, including red leaf monkey, honey bear, gibbon, samba, barking and mouse deer.
Agricultural land is not a suitable habitat for orang utans, so their natural habitats – forests and mangrove swamps – are disappearing. (Orang hutan means person or people of the forest; orang sungai river people; orang laut sea people; orang Inggeris an Englishman.) They often end up foraging for food on palm oil plantations and are killed as pests or hunted for sport. Often, too, a mother is killed in order to capture her infant to be sold as a pet, sometimes smuggled abroad. Forest fires can also kill hundreds at a go. So the number of orang utans in the wild, in both Borneo and Sumatra, is diminishing. If they become extinct, we can primarily blame palm oil. And for the glut of palm oil we can partly blame western governments for their lunatic subsidy of biofuel.
There are two species of orang utan, one in Borneo and one in Sumatra. The Bornean is Pongo pygmaeus and the Sumatran Pongo abelii. They were probably separated 1.5 million years ago, when they ranged all over southeast Asia and into southern China. There are now perhaps 45,000 Bornean orang utans in the wild, and 7,500 Sumatran. They are confined to spots in west and east Borneo and to northwestern Sumatra, and were probably so confined in Sumatra in Wallace’s day. Another estimate gives 10,000-30,000 Bornean orang utans. The Sumatran orang utan is listed as critically endangered on the IUN Red List, and the Bornean orang utan endangered, and both are CITES Appendix I species.
Within the grounds of the forest reserve sits the Sepilok Orangutan Rehabilitation Centre (SORC). It is funded by a UK charity and by entry fees. When someone finds a young orang utan, or sees one kept as a pet, they can call the centre, which, if there is space, will take it to Sepilok for a “rehabilitation” free of the connotations of the gulag.
Outside the centre I bumped into a colony of pig-tailed macaques.
The pig-tailed macaque, Macaca nemestrina, spends more time on the ground than its familiar long-tailed cousin. But they still have to learn to climb trees, and it is not easy, particularly going down.
Its groups are usually led by a dominant male, which is built a built like a baboon (its apparent size is exaggerated by the fur). Some live alone. Smart simians, these: they are not part of the programme, but they free-ride on it.
In the centre there is an exhibition devoted to orang utans and Sumatran rhinoceroses, an audiovisual theatre and some boardwalks leading through the edge of the forest. One of the boardwalks leads to a large platform situated opposite a couple of smaller platforms. These are feeding stations. The smaller platforms have horizontal ropes leading to them from nearby trees, so that the orang utans can reach them without touching the ground. Wallace observed that they never touch the ground if they can help it, unless they really need to find water in the dry season. Wallace thought, reasonably, that they drink water collected in leaves in the canopy. In fact they open up the bark of a particular tree – the tree from which the river people make gongs - and drink the juice.
Orang utans eat a huge variety of fruit, bark, nuts, honey, leaves, flowers, insects, bird eggs and even mineral earth. They even eat durian; in fact Alfred Russel Wallace reports that they are very partial to them. (Dinosaurs probably ate them too. Durians, like mangoes, have been around for 70 million years.) They have very solid jaws, and fearsome canines, which help when peeling fruit. Like us, they have 32 teeth.
Orang utans have the most intense parental relationship of any mammal other than humans. Mothers carry their offspring for five years and may suckle them, off and on, for six or seven years. A mother sleeps with her infant every night in a nest. The Borneo species gives birth on average every eight years. Once a new baby is born, the older child is displaced in its mother’s attentions.
Adult males live alone and can migrate very long distances. Females stick closer to the hearth. Male and female come together in a ‘consortship’ of up to a week. The resulting gestation lasts for 250 to 260 days. Newborn infants usually weigh less than 2 kilos. Their diet is wholly milk for the first six months, and then they are gradually weaned on to pre-chewed food and may be fully weaned from their fourth year. They cling to the mother’s fur as she moves around.
Wallace, who kept a baby orang utan orphan in Borneo for three months until it died (he couldn’t obtain milk), found that orang utan infants are relatively helpless. They display a need for company and attention comparable to human babies and react in a similar way when these desiderata are withdrawn. Wallace’s infant liked to grasp things, with a strong preference for Victorian facial hair. And it soon learnt to enjoy being washed and towelled.
If you plot primates’ gestation periods against their weight, you find that humans are an outlier: our gestation periods should be much longer given our size. One theory is that the human gestation period is limited by the relatively large brain, which could not fit through the birth canal if kept in utero any longer. A human brain is about 2% of adult body volume, an orang utan’s 0.6%. This would help explain why human babies are even more helpless than orang utans. (It also explains why Marilyn Monroe swayed fetchingly: women's hips are bigger than their chimp cousins' so as to accommodate big baby heads.)
Many of the arrivals at the centre are young. Upon arrival the foundling lives in a hammock in quarantine for ninety days (which would make it novantine?), and is bottle-fed every four hours. An identification number is tattooed on to the leg of the sedated ape. Then they go to a clinic, where they are checked for diseases such as TB. The clinic also takes care of rhinos, bears, gibbons, macaques (why?), leopards, pythons, otters, deer, pangolins and birds. The waiting room must look like a Gary Larson cartoon.
New entrants under a year old are bottle-fed, cuddled a lot and given warm baths. They are taken home by centre staff to be given night-time feeds, until they are able to drink from a bottle unaided. They like to cuddle soft toys.
Many of the most important orang utan skills are acquired, not innate. They learn from their mothers. At the rehabilitation centre they have to be taught orang utan culture: how to swing, climb, find food and build nests. Orang utans sleep in nests. They make a new nest every night, which takes about twenty minutes.
The aim of all this is to release each orang utan into the forest to fend for itself. But it is a long process. At first the orang utans are moved into an outdoor nursery and their cages are opened. They cautiously wander out, but stay close to the cages and come back to sleep in them at night. The cages are near the feeding stations. Here fruit and milk are made available at 10 am and 3 pm every day, and crowds of people come to watch, particularly in the morning.
The emotional support is gradually reduced. The inmates are encouraged to learn to find things for themselves. There are in fact four feeding platforms, the farthest being a kilometre into the forest. The orang utans are gradually moved from one to the next. At four they are weaned off all human attachment. It may take six or ten years for them to learn how to live entirely independently; even then, they may visit a feeding platform every now and then.
I visited two of the afternoon feeding sessions. At the first, there were perhaps 15-20 tourists and two orang utans turned up. They munched through extraordinary quantities of bananas before heading off along the ropes. Usually they walk suspended from the ropes, using all four hands; sometimes they brachiate with the upper limbs only.
They have very short legs and very long arms, which are almost all forearm; on Wallace’s figures, the armspan is nearly twice as long as the height from heel to head. Wallace’s adults – he shot about 17 orang utan - were all about four foot one tall. According to the information at the centre, adult males can reach about 1.40 m, which is about four foot seven (I have seen other figures that suggest males can reach 1.75 m). Their wingspan can reach 2.4 m, or nearly eight feet. Adult females can reach 35 to 50 kilos in weight in the wild, although much more in zoos. The two species are strongly sexually dimorphic. Males can reach up to 90 kg (and possibly much more). Indeed, Pongo is the heaviest fully arboreal mammal and the largest fruit eater. In the wild, they live to about 35; longer in zoos.
They have extraordinary hands. Their fingers are thick and very long, the thumbs very short, which keeps them out of the way. However, contrary to received opinion their thumbs are clearly opposable, as can be seen here. The male’s hands are about twice as wide as the female’s, and really are as big as spades. They have very tough palms. Their nails are black and long. The apes are extraordinarily strong: four times stronger than an adult male. (Which adult male? Me, or Lennox Lewis?)
They have very mobile hip joints, which allow them to hang comfortably in positions that appear excruciating.
They have a very wide range of physiognomies and hairstyles, and they display a wonderful and touching diversity of facial expressions on very human faces.
Most zoologists preciously warn against the dangers of anthropomorphism; but we lay people can react as we like. (Not all do: I recommend the fascinating books on chimpanzees by Frans de Waal, starting with Chimpanzee Politics.)
Outside consortship periods, males live very solitary lives. Not all are landowners, but all males with a territory display flanges on the side of the face. A territory is useful because when a female in oestrus wanders on to your land, she is yours. This pulling strategy is called call-and-wait.
On the second morning I went for a walk through the dipterocarp forest and missed the morning feeding session. I saw instead a lot of fat skinks, butterflies and a gorgeous rhinoceros hornbill, Buceros rhinoceros. I only saw it because it flapped from one branch to another, its wings making a loud and disconcerting noise as it did so (any noise in the jungle is disconcerting). Rhinoceros hornbills are the largest hornbills, growing to 1.2 metres in height.
I also saw several impressive ant superhighways. I followed one of them for about ten metres along a path and across several roots and branches before losing it as it headed up a tree. To a small animal the path would be impassable; indeed a far larger ant stood stymied like a tourist in Saigon, unable to cross.
On the second afternoon it was raining and there were about forty human tourists, including an Italian group with a typically atrophied sense of res publica. A small female arrived, one of the pair that had dined the day before, an ugly girl with a squint. She was pregnant. Then a lot of pig-tailed macaques crashed the event. Most roosted like bats under the feeding platform, occasionally hoisting themselves over the parapet to steal a banana.
But they gradually be came more confident and aggressive, and eventually the orang utan was overwhelmed by numbers; so they robbed as well as stole. One individual – far smaller than her – was insanely aggressive and forced her to retreat along the ropes about a hundred metres. Orang utans are well known for being very gentle, except to each other, but her retreat was in any case prudent, as macaques operate like the musketeers in practice and NATO in principle: attack one macaque and they all attack back, scratching and biting. Humans are advised to retreat too, and in Ubud I followed this advice with alacrity.
However, judging by what I saw outside the centre, macaques do seem to be terrified of cats.
Both orang utans swung obliquely around the feeding station and landed on the boardwalk. They then knuckled one behind the other along the railing for several hundred metres, hemi-surrounded by a crowd of excited tourists. I stopped by the railing a couple of times, scattering Italians, and watched the hirsute pensioners shuffle past within inches. I obeyed the injunction against touching them, since a) it is rude, b) they are shy and c) one can catch or give disease.
Then the leader hoisted herself into a tree and waited while the second one lowered his face like a Chinaman eating noodle soup and sucked up insects from the railing. Then he too hoisted himself up and they were gone.
A kilometre down the road from the SORC is the Rainforest Information Centre, where I spent a happy day wandering through dipterocarp forest. There are many species of birds in the forest, including woodpecker, trogon, pigeon, minivet, bee eater, broadbill, malkoha, kingfisher, shama and shrike, and there is a short canopy walkway built of metal.
There is also a botanical garden exhibiting, among other things, plants grown commercially in Borneo, and a number of pitcher plants and orchids.
Not to mention the usual skinks and dragonflies.