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Dugongs, like dolphins and whales, are mammals adapted for life in the ocean.  But unlike cetaceans, dugongs are not designed to hunt and are slow-moving and graceful herbivores.

Distribution

The dugongs’ large range is thought to span 37 countries and includes tropical and sub-tropical island and coastal waters.  They live in the coastal areas of the Indian Ocean, the Indonesian archipelago, and the southwestern Pacific around the Philippines.  But they are likely to be extinct in much of this range, or populations fragmented.  

Habitat

Usually found in coastal waters, the dugong frequents wide shallow bays and mangrove channels, plus the lee of inshore islands.

Diet

The dugong spends much of its time feeding and consumes up to 25kg of seagrass each day.

Adaptations

Adaptations for life in the sea include a streamlined body, a wedge shaped tail and strong flippers.  As mammals, dugongs are air-breathing and must return to the surface to breathe every 5 to 10 minutes.  Their nostrils are at the front of their head allowing them to breath with the rest of their bodies underwater. 

Behaviour

Feeding is dugong’s principal activity, typically in water 1.5m deep.  Digging or rooting is probably part of the feeding behaviour.  Frightened animals can make a whistling sound while calves can give bleat-like cries. Though now rare, herds of several hundred animals were formerly known.  Average swimming speed is 10km / hr.

Society

Dugongs are usually either solitary or in loose herds of up to 30 animals, that move around slowly together.  Herds of several hundred animals have been reported.

Reproduction

With a 70-year lifespan, dugongs mature around 9 years.  After mating and 13 month gestation, females give birth to a single calf.  Population growth is very slow as a female will only give birth every 2½ to 5 years.  A calf suckles for around 18 months.