The Plight of the Asian Colobines
Profiling Singapore’s banded leaf monkey and Vietnam’s Tonkin snub-nosed monkey
Asian colobines, or leaf-eating primates, are a diverse group with at least 44 species recognised throughout the region. Highly endangered and living in remote forests, this article brings to light the plight of Singapore’s banded leaf monkey and Vietnam’s Tonkin snubnosed monkey.
Asian colobines are vegetarians who own a large ruminant stomach like that of a grazing cow, allowing them to digest huge amounts of plant material. Although loosely called the leaf-eaters, they tuck into a feast of fruits whenever they are in season. Asian colobines are a diverse group with at least 44 species recognised throughout the region. They live in a multitude of habitats from tropical and subtropical forests (douc langurs), swamp forests (proboscis monkeys), along coastlines (silvered leaf monkeys) and in mountains as high as 4,700m in elevation (black snub-nosed monkeys).
The banded leaf monkey of Singapore
Singapore has one species of Asian colobine – the banded leaf monkey. When Sir Stamford Raffles founded Singapore, he also discovered a monkey on this island nation completely new to science. A study in black and white, this monkey was a startling beauty, possessing a coat of midnight fur with ivory bands traversing on the underside of its body, hence the name banded leaf monkey.
This species used to roam the expanses of forests from Changi to the far stretches of Tuas up to the 1920s. Deforestation for urban development shrunk
their habitat, confining them to the Central Catchment Nature Reserve (CCNR) and Bukit Timah Nature Reserve (BTNR), a decline which unfortunately did not stop there. The subsequent construction of the Bukit Timah Expressway (BKE) in the 1980s disconnected the two green lungs of Singapore, and with the eventual eradication of the population of banded leaf monkeys in BTNR, CCNR became the last refuge of Singapore’s banded leaf monkeys.
With funding support from the Wildlife Reserves Singapore and the Jane Goodall Institute (Singapore), and logistic support from the National Parks Board, more is known about the population size, feeding habits and reproduction of banded leaf monkeys. At present, it is estimated that there are 40–60 banded leaf monkeys left in Singapore. In addition, with the recent re-establishment of a green connectivity via the Ecolink across the BKE, it is hoped that the banded leaf monkeys can once again call BTNR home. While there seems to be a glimpse of hope for our banded leaf monkeys, another Asian colobine in Vietnam may not be so lucky.
The Tonkin snub-nosed monkey of Vietnam
All monkeys are adorable. But some looks push the boundaries of what is accepted as cute. Try a bulbous head of white fur, a pair of permanently disgruntled eyes, a characteristic up-turned nose and pink sausage lips. Such artistry belongs only to the Tonkin snubnosed monkey, a lesser-known relative of the golden snub-nosed monkey. While alpha males are known to bring such avant-garde appearance to an extreme, females trail closely behind. They may have an amusing face, but their fate is far from funny.
Since its discovery in 1912, there were very limited sightings of the Tonkin snub-nosed monkeys, and they were believed to be extinct until its rediscovery in 1990. The Tonkin snub-nosed monkey is now considered the top 25 most endangered primates in the world. They can only be found in four isolated areas in two provinces (Hà Giang and Tuyên Quang) in northern Vietnam, with fewer than 200 individuals left. Hunting and habitat destruction are often cited as major threats to wildlife, driving them to extinction.
A decade ago, researchers would hear between five to seven gun shots on a daily basis in one of the nature reserves. Notwithstanding such direct threats to their survival, a lack of knowledge of the existence of these endangered primates denies them from protection and conservation.
Over the past few years, in addition to patrolling and gun confiscation, conservation initiatives have also started to focus on increasing awareness about the Tonkin snub-nosed monkeys. One of the ways is through the distribution of calendars with images of these primates to local communities and schools every year, with the aim of bringing these charismaticallypeculiar faces to every household.
The first thing we need to know is that these colobines exist. Akin to the orangutans in Indonesia who suffer when the forest fires burned, a population of the Tonkin snub-nosed monkeys disappeared when the forests in remote northern Vietnam were bulldozed for a hydroelectric dam. Actions to arrest such activities, to minimise damage and to rebuild what’s lost can only be initiated if we know what we are going to lose. ag
ANDIE ANG is a PHD candidate at the Department of Anthropology at the University of Colorado Boulder ( www. andieang.org) and a board member of the Jane Goodall Institute (Singapore). She is also the founder of Primate Watching ( www.primatewatching.com), an online web resource about primates of the world.