Wednesday, 13 April 2011

Dugong Ivory at Changi Beach!

A rare Dugong tusk (ivory) in its own bone casing was found at Changi Beach by Timothy Pwee and Gloria Seow.

We stumbled upon this unexpected and superb treasure during a low tide walk on 26 March 2011. When we first laid eyes on it, the bone casing had a little point sticking out, looking more like a giant barnacle. Only when cracked was the tusk exposed. However, we still could not fathom its identity, only guessing that it came from a big marine or land mammal. After scrolling through numerous photos on Google Images, we finally found the answer!

Locally, dugongs are very rare. Known also as sea cows, they graze on the sea grass beds off Changi Beach , Chek Jawa in Pulau Ubin, Pulau Tekong, around the mouth of Johor River and along the coast of Peninsular Malaysia. They tend to feed at night to avoid human contact. Globally, its population is discontinuously distributed from East Africa, to India, Southeast Asia, all the way to down to Australia. Only male dugongs that reach puberty (around age 12 onwards), or very old females sport visible tusks. Our dugong’s tusk measured 9.5 cm (adult males: 17 to 22 cm), while its bone casing was 20 cm long.
Growth layers on tusks can be used to age the mammal.

Culling from internet postings, it appears that the last confirmed Singapore sightings were in 2001 and 2006. Dugong carcasses were found at East Coast beach and Pulau Tekong respectively. A lucky contractor constructing the Chek Jawa boardwalk apparently encountered a live one in 2006. Ria Tan and her friends possibly spotted another live dugong as recently as March 2011, also in Chek Jawa. An old 1999 aerial survey counted 19 dugongs around the islands off Mersing (Pulau Rawa etc).

Did you know that dugongs are distantly related to elephants? Notice their tusks, small eyes and thick hides. Dugongs are differentiated from the similar-looking manatees by having a fluke (fish) tail. Manatees have paddle tails. Dugongs are true marine mammals, whereas manatees can live in both freshwater and coastal marine habitats.

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