Dugongs
in Singapore? Dugongs used to be common in the Johor Straits
but were considered locally extinct by the 1980’s. In the late 1990’s,
however, there were increased encounters with dugongs in the Johor
Straits. Former residents of Chek Jawa have reported sightings of
dugongs on Chek Jawa.
Are there Dugongs on Chek Jawa?
Dugongs need to eat lots of seagrass so they keep moving and are usually
not permanently resident in one small location. Dugongs can travel
several hundred kilometers in a few days as they feed from place to
place. A place like Chek Jawa may be only one of their many feeding
stops. More study will be needed to determine if dugongs visit Chek
Jawa regularly.
The Dugong is one of the few large animals that can digest fresh seagrass.
Seagrass is the dugong’s main food. So not
surprisingly, it is also sometimes called the Sea Cow! A dugong often
‘cultivates’ a favourite patch of seagrass by cropping it frequently.
This promotes faster growth of young tender leaves which the dugong
prefers to eat.
The dugong is an air-breathing mammal that is well adapted to its
underwater lifestyle and seagrass diet. A dugong's mouth faces downwards
to munch on seagrass and it has large, grinding teeth that grow continuously.
Its digestive system is also adapted for tackling seagrass. Its front
limbs are modified into flippers, used for steering when swimming,
or for ‘walking’ as it floats over the ground when feeding. A dugong
has no hind limbs but has a powerful tail to swim with. Its grey,
smooth skin is thick and sparsely covered with hair. A dugong has
lots of stored fat (blubber) which provides bouyancy. The dugong is
the only herbivorous mammal that is strictly marine.
Dugong babies: The mother dugong
gives birth in shallow waters, usually to a single calf. The calf
clings to the mother’s back as she grazes. She suckles her baby for
up to 18 months. The juvenile might stay with her for another year
after that. It is almost impossible for the baby to survive if its
mother dies. Dugongs reproduce slowly, taking 9-10 years to reach
sexual maturity and give birth only every 3-7 years. They can live
up to 70 years.
Status and threats: The dugong’s
natural predators are sharks, killer whales and crocodiles. But man
is the main threat, hunting dugongs for their meat, oil, skin (for
leather) and for medicinal uses. Dugongs also drown when trapped in
fishing nets and are injured by boat propellers. Mostly, they are
threatened by the loss of seagrass habitats. Dugongs used to form
herds of hundreds, now groups of six are the average. Dugongs are
considered highly endangered globally; listed on CITES I and considered
by the IUCN to be vulnerable to extinction. |
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The dugong is well adapted for
eating seagrass
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The
English name dugong comes
from its name in Malay: 'duyong'
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What
is the difference between a dugong and a manatee?
A dugong has a fluked tail like a dolphin, while a manatee
has a rounded paddle-shaped tail.
While manatees are found along the coasts of the New World
and Western Africa, dugongs are found from the western coasts
of Pacific Ocean to the eastern coast of the Indian Ocean,
including the Red Sea. |
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