Fast Fact Attack: Endangered Species No. 32 – Proboscis Monkey

Proboscis monkey 3

Photo: Frank Wouters

With its huge fleshy nose and its World War II flying jacket, this endearing primate is bound to raise a smile on most faces.  A native of Borneo, it emits sounds eminently suited to its nasal abnormalities – it honks.  From a special honk for reassuring infants to its alarm honk when sensing danger, it manages a whole range of honk tones.  And, its nose stands out straight when doing this.  The male’s is so large it gets in the way of eating, hanging down over its mouth.  Only the male of the species has this nose.  Another bizarre distinction of the proboscis monkey is the large pot belly.

But, that’s not all.  They’ve managed to dispel any ideas that monkeys do not like water. They are incredible swimmers.  They have partially webbed feet and a penchant for leaping from high branches into the water.  They swim on or under the surface.  They can swim submerged for up to twenty metres at a time.  They appear to do the breast stroke as they move swiftly through the water – amazing!   If they have the misfortune to encounter a crocodile, they have a plan.  They slide quietly into the water and glide silently past it, taking care not to splash.

They are the largest of Asia’s monkeys, with males reaching up to fifty pounds in weight; the females being more or less half of that.  Their coats of fur are light brown on the bulk of the body becoming red near the shoulders and head.  They have grey arms, legs and tails.  Their chambered stomach harbours symbiotic bacteria to aid digestion.

Groups of proboscis monkeys (troops) typically consist of one male to six females – something on the lines of a harem.   The breeding season is from February until November.   Females give birth to just one baby at a time.  The gestation period lasts about 166 days.  Babies are usually born during the night.  All the females in the troop pitch in to help with the new babies, who stay with their mothers for about a year, or until she gives birth again – whichever comes first.

Riparian-riverine forests, coastal lowland forests (including mangroves) where tidal flooding occurs,  peat swamps and freshwater swamp forests.
Borneo: Brunei, Indonesia, and Malaysia
What they eat

Leaves, seeds,  fruits and occasionally insects.  The proboscis monkeys will only eat unripe fruit.
The sugars in ripe fruits can ferment in their stomachs and cause fatal bloating. [1]

Habitat destruction through land clearance and conversion, logging and settlement.  Oil palm plantations have depleted huge tracts of their habitat.  Forest fires have also had a massive impact.  In 1997 to 1998, fires decimated a huge proportion of what remained at the time.
Its natural predators include crocodiles and the clouded leopard.  In some parts, proboscis monkey-meat is considered a delicacy.  And, here we go again, they are hunted for traditional Chinese medicine.  In their case,  for their intestinal bezoar stones.   
It really is time these people stopped eating and grinding up everything with a heartbeat – BEFORE they are entirely bereft of wildlife.

Status: Endangered
The proboscis monkey (Nasalis larvatus) was listed by the International Union for the Conservation of Nature on its IUCN Red List as Endangered in the year 2000, with an estimated 50% reduction in the population in the following ten years.  In 2008, numbers were thought to be less than 6,000.  The conversion of land to palm oil plantations is an alarming and escalating problem, which can only be addressed by the consumer choosing not to buy palm oil based products.

“The more helpless a creature, the more entitled it is to protection by man from the cruelty of man”
Mahatma Gandhi


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