The proboscis monkey (Nasalis
larvatus) or long-nosed monkey, known as the bekantan in Indonesia, is a
reddish-brown arboreal Old World monkey with an unusually large nose. They are
also called the Monyet Belanda Monkey, which means the long nosed Monkey. It
belongs to the Old World classification. In the Egyptian Culture they were
worshipped as a very unique animal and believed to be special to the gods.
Proboscis means nose, which
explains their name, as the noses on the males of this species are clownishly
large. These unique monkeys inhabit the island of Borneo in southern Asia and
nowhere else on the planet. Their over-sized noses allow the male Proboscis
monkeys to make loud bellowing noises to warn of predators or to attract mates.
The other notable feature of these
monkeys is there protruding stomachs, which allow them to digest their primary
food of unripe fruits.
The proboscis monkey is only found
on the island of Borneo in Southeast Asia. It is present in all of the
countries that make up Borneo, namely Malaysia, Brunei and Indonesia.
The long nose if this Monkey is a
very distinct feature that separates it from all other species. In fact, when
people first noticed it they didn’t
even think it was a Monkey due to the look of it. The males have a nose that is
even larger than that of the females. It is believed that a larger nose is
going to attract females. The nose can be up to 7 inches long.
They have unique colour of
orange-brown coat with grey arms, legs and tail. Females are smaller and
typically weigh 7-12 kg. The male has a head to body length of 65-75 cm with
females slightly smaller at 55-65 cm. The male is one of the largest monkeys in
Asia and typically weighs 16-22 kg but can weigh as much as 30 kg.
It is believed that the large nose
allows for the sounds to be bolder than that of other Monkeys, they have very
loud warning calls. They can live in groups that range from 10 to 30. The
Monkeys don’t
always stay in the same group though. They can move from one to the next
frequently. This is very different from most other groups of Monkey species.
They love swimming, and they are able to swim very well even in deep water. For that case, they normally move from one island to another. It also offers them a place to cool off and for having some fun playing around. They have been seen walking in an upright position along the trails in the forest.
The nose of Proboscis monkey develops
with age. Females have smaller noses whilst the male’s nose can be up to 18 cm in
length. Both male and females have large stomachs which look like pot bellies.
Researchers have found that a
bigger nose alters the monkey’s
vocalizations so that the male’s
bulk and nose size is communicated to females in faraway locations. The sound
impresses females and can intimidate other males. Males with big noses also
have larger testes and also weigh more than smaller nosed proboscis monkeys. Male
proboscis monkeys with larger noses attract more females to their harem.
HABITAT
The proboscis monkey lives in
riverine forest, lowland forest, mangroves and peat swamp. It is usually
restricted to habitats within 1-2 km of a large waterway. They never straying
far from the island’s
rivers, coastal mangroves, and swamps.
They live in organized harem
groups consisting of a dominant male and two to seven females and their
offspring. Various groups often congregate near water at night to sleep. They
are a highly arboreal species and will venture onto land only occasionally to
search for food, they are rarely come to the ground.
DIET
Proboscis monkeys eat leaves,
unripe non-fleshy fruit, seeds and occasionally insects. They have large,
chambered stomachs that contain symbiotic bacteria for fast digestion.
LIFE SPAN
The Proboscis Monkey has a short
life span in the wild of about 13 - 20 years. If conserved they may live up to
30 years.
The two key threats to the
survival of the proboscis monkey are habitat destruction and hunting. These
monkeys live in coastal and riverine habitats. Such areas are often subject to
extensive human development activities. Large scale clearing of riverbanks and
mangrove forests across Borneo has had a major impact on this species.
REPRODUCTION
They reproduce sexually by mating.
Both sexes can initiate mating and do so by making pouting faces. Females
attain sexual maturity at five years old, they present themselves and shake
their heads from side to side. Females are the ones that initiate mating, Males
may vocalize. Mating can take place throughout the year, when there is plenty
of food. Juveniles often interrupt and harass mating couples and sometimes pull
the male’s nose.
The gestation period is around 6
months. The birth takes place at night or early morning. Infants are born with
black fur and a bluish face that will soon turn pinkish. They develop adult
colouration at 3-4 months. The infants start eating solids around 6 weeks and
are weaned at 6-7 months. Mothers allow other females from their troop to hold
their young.
The young stay close to their
mothers for around a year then become more independent. Females stay with the group whilst males
leave at 18 months and join bachelor groups.
That's all about Proboscis monkeys, if you've any opinions
about this article feel free to leave your comment below. See you next time!.
Posted by: Lusubilo A. Mwaijengo
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