Up close with the Dutchman

By Cheryl Poo

Monkey behaviour

The proboscis monkey is endemic to Borneo. Usually found in tall trees near waterways, these primates roost in the highest branches for the night after a day of foraging for food in the forest. The primate earned the name bekantan and orang Belanda or Dutchman because their long noses and pot bellies resemble those of Dutch colonisers. Research in the past five years indicates that Sabahan populations are found in the Kinabatangan floodplains, Klias Peninsula and Segama.

These creatures are social animals that often gather in troops of five to 15, sometimes up to 30. Similar to the social hierarchy in a pride of lions, single males in multi-female troops are common.

According to Goossens, the size of the group depends on the male's appeal. And like most creatures, the males often fight for their reign. Apparently, the proboscis monkey is preoccupied with sex.

"Its penis is erect 18 hours a day," said Goossens.

The primate derives its name from its long, phallus-like nose that dangles like a pendulum over its mouth. They move easily through the forest, swinging from tree to tree and are often found along riverine mangroves where they graze on fruits, flowers, leaves, seeds, and aquatic vegetation.

Folklore has it that the proboscis monkey was hunted for its flesh but Goossens thinks that the practice is now uncommon, if not entirely phased out. He adds that Muslims do not eat primates.

At any rate, the bigger threats to proboscis monkeys lie in the increase in oil palm plantations and logging activities. These rob wildlife of their natural habitats. Furthermore, the reduced landscapes can result in genetic disorders among species such as low genetic diversity, weaker immune systems and lower adaptability to different environments.

"A new virus and bacterial outbreak (from inbreeding) may wipe out the entire species, like the Ibola virus attack on cattle in Africa," said Goossens.

Habitat loss will also lead to the scarcity of food for the proboscis monkey as their unique digestive system requires a specified diet. In fact, it is similar to that of cattle. A Youtube video depicts a large - presumably male - proboscis monkey remasticating its meal of leaves.

The leaves go through a rumination process and turn into digestive enzymes through a series of fermentation process in the intestines. Certain foods, such as bananas, though typical for primates, are taboo for proboscis monkeys.

"It can cause enough gassing to kill the monkey," says Senthivel.

Fortunately, it has not come to a point where these mammals are forced to take on a different and harmful diet due to food shortage.

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