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Up close with the Dutchman

One little-studied primate gets some attention from scientists. -The Star/ANN
Cheryl Poo

Tue, Aug 09, 2011
The Star/Asia News Network

MALAYSIA - Twack! The proboscis monkey jolted violently as a tranquillising dart sank into its flesh.

It was a matter of seconds before it went limp and crashed into an outstretched net below.

The Danau Girang Field Centre research team acted quickly; they only had an hour with the creature before it awakens. They had two tasks: extract bodily samples and tag it with a satellite collar. An intravenous needle was inserted for a blood sample, the creature's hair combed for parasites, a finger stuck into its anus for faecal samples and saliva harvested for bacteria and virus detection.

Minimum sedative is preferable as the operation team has to wait until the darted animal is alert, otherwise a carnivore might kill it in its stupor.

At 24kg and 1.2m, this was the biggest proboscis monkey the team had encountered so far. It is probably head of its clan.

Dr Senthivel Nathan, Sabah Wildlife Department senior wildlife veterinarian, had described the tranquillising operation to me during a recent brief excursion into the Kinabatangan forest reserve in Sabah.

I had left the hustle and bustle of city life for a couple of days to find out more about the endangered species and experience our Bornean forest before it disappears. Earlier, my request to tag along the nocturnal mission was met with a firm no.

"Far too dangerous for you," said Senthivel, shaking his head dismissively. He probably did not want to startle me with the possibility that I could be mauled by a clouded leopard or swallowed whole by a crocodile in the wild.

That was the first proboscis monkey to be tagged with a satellite collar, to enable the research team to monitor the primate's location and environment.

The Danau Girang Field Centre (DGFC) is located in a 27,000sqkm parcel of wetlands, known as Lot 6, in the lower reaches of the vast Kinabatangan Wildlife Sanctuary in Sabah. To get to the field centre, I had taken a 30-minute boat ride downstream from Batu Putih, a village 90km south of Sandakan.

It is where Senthivel works closely with conservationist and DGFC director Dr Benoit Goossens, who was previously involved in the conservation studies of other endangered wildlife such as the orang utan in Sumatra, black rhinoceros in Zimbabwe as well as red and giant pandas in China.

Bisected by the Kinabatangan river, the wildlife sanctuary comprises 10 fragments of primary to secondary forests, significantly impacted by villages, agriculture and oil palm plantations.

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.

Primate study

The research on the proboscis monkey at Danau Girang is funded for three years by Yayasan Sime Darby, the corporate social responsbility arm of the Malaysian multinational, as part of its Big 9 Campaign that conserves eight other endangered species: the hornbill, pygmy elephant, tembadau, Sumatran rhinoceros, clouded leopard, orang utan, sun bear and Malayan tiger.

"The results of the work carried out will be presented and discussed with all stakeholders involved in the conservation of the proboscis monkey for further sustainability," said Yayasan chairperson Caroline Christine Russel.

Ultimately, the RM1.5 million (S$600,000) programme will enable the Danau Girang team to perform an in-depth study of the species that will result in a comprehensive proboscis monkey conservation plan for Sabah. It will promote the restoration and reestablishment of wildlife corridors along large rivers in Sabah.

The funds also cover Senthivel's fees at Britain's Cardiff University for a doctorate in conservation biology, molecular ecology, conservation genetics, geographic information system and management.

The DGFC works closely with the English university, enabling science students to do wildlife research training at the sanctuary.

Although the conservation plan outlines the possibility of translocating the proboscis monkeys, it would only be necessary if the research team finds "perverse habitats", like overly cramped spots.

"Or if we find pockets of population so small that it's not viable for healthy reproduction," Goossens explained. "We are still observing."

Like humans, animals need their living space. For these creatures, increase in contact means more inter-species fights and disease transmission.

"Our research is really still at its infancy stage. I hope we wouldn't have to transfer the monkeys anywhere," Goossens said. "But all of that depends on the information we gather from their samples."

The team will tag 10 monkeys with satellite collars and extract body samples from 100 proboscis monkeys for their research. They are targeting samples from 20 individuals from five areas: the east and west coasts of Klias Peninsula; Kinabatangan and Sandakan Bay; Segama river; Paitan, Sugut and Beluran in north-east Sabah; and Tawau.

"We want to learn how the proboscis monkey is using these areas," says Goossens.

So far, they have sampled five monkeys from Kinabatangan.

A 1985 study estimated the total population of the bulbous-nosed primate to be 250,000 but that figure has depleted greatly since. According to a 2011 publication, The Natural History Of The Proboscis Monkey authored by Dr Ikki Matsuda, John Sha and Henry Bernard, there are a scant 6,000 proboscis monkeys in Sabah, less than 100 in Sarawak, a little over 300 in Brunei and less than 5,000 in Kalimantan.

It's a startling reality for conservationists like Senthivel, whose own survey reflects that only 15% of the world population of proboscis monkeys live in protected areas.

Even as the research team attempts to better understand the species, they are only too aware that the ultimate impact of losing any one organism will result in rippling effects.

 

 
 
 
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