These plump, large, gray hotdogs with eyes are named after the Malay word duyung or lady of the sea ¹. And they’re vegetarians. They are part of a small group of plant-eating mammals that live their entire lives in the water ².

And unlike other marine mammals, like dolphins or whales, they are actually more closely related to elephants ³.

Thanks to the wonders of genetics, scientists recently determined that Dugongs are one of the closest living relatives of elephants, even though their common ancestor lived over 60 million years ago ⁴.

A closer cousin of the Dugong is the Manatee, which looks quite similar. One of the easiest ways to identify them is by looking at their tails. The Dugong has a tail that looks like a dolphin’s or a whale’s; it has two pointed ends. But the Manatee has a tail with a round end.

Dugongs will typically have little friends with them, like the Golden trevally’s or Gnathanodon speciosus. These are small yellow and black fish that follow Dugongs closely as they graze seagrass. The reason is because they will catch any small animals that are dug up from the Dugong’s meal ⁵!

Dugongs love two things: warm water, and seagrass. An adult Dugong can eat up to 30 kilos a day ^{6, 7}. They spend most of their day eating to consume energy for their large bodies. They can weigh up to 900 kilos and grow as long as 4 meters ⁸!

Dugongs can only be found along the coasts of India, South Asia, the Philippines, and Eastern Africa; about 120,000 km of coastline ⁹. In one study Dugongs were recorded to have moved up to 500 km from where they were last noted. Some make such a journey to move toward warmer waters ¹⁰. 

Unfortunately they are considered extinct around several islands including the Maldives and Taiwan ⁹. Because Dugong spend most of their time close to the sea surface ¹¹, they’re exposed to harm from boat propellers, and are easy to find by hunters. In the Philippines, Palawan has the most number of Dugongs with much lower numbers in Mindanao, the Visayas and southeastern Luzon (Polillo Island, Quezon) ⁶.

Sadly, the Dugong is one of the most endangered marine mammals in the Philippines ¹².

How you can help

Today, communities in northern Palawan are working on a conservation and management plan for Dugongs and their habitat ¹³. You can visit and support the work by joining tours led by Tagbanua communities in Calauit Island in Busuanga ¹⁴. If you’re lucky, you will see a local Dugong named Aban. 

Erina Molina, a young marine biologist currently working on Dugong conservation told National Geographic, “The best time to see dugongs here is from March to early June, when the water is calm and clear ¹⁵.”

More Dugong art

Sources

1. G. Yan, 2018. “Swimming with the mermaids in Northern Palawan.” Rappler.com. Last accessed: October 2, 2019.
2. Physiological Ecology and Bioenergetics Lab. Studies Investigating the Reproduction, Energetics, and Nutrition of the Sirenia. Conservation Biology Program of the Department of Biology at the University of Central Florida. Last accessed: October 4, 2019.
3. EDGE of Existence. 41. Dugong. The Zoological Society of London. Last accessed: October 2, 2019
4. N. Rohland et al., 2007. Proboscidean Mitogenomics: Chronology and Mode of Elephant Evolution Using Mastodon as Outgroup. PLoS Biol 5(8): e207. https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.0050207
5. R. Mittermeier, et al., 2014. Handbook of the Mammals of the World. Vol. 4. Lynx Edicions in association with Conservation International and IUCN.
6. Department of Environment and Natural Resources Biodiversity Management Bureau or DENR-BMB. “Marine Wildlife Watch of the Philippines joins the DENR as conservation partner.” Last accessed: October 2, 2019
7. LV Aragones, 1994. Observations on dugongs at Calauit Island, Busuanga, Palawan, Philippines. Wildlife Research 21(6) 709 – 717. www.publish.csiro.au/wr/WR9940709
8. S. Husar, 1978. Dugong dugon. Mammalian Species, No. 88, pgs. 1-7. The American Society of Mammalogists.
9. Marsh, H. & Sobtzick, S. 2015. Dugong dugon. The IUCN Red List of Threatened Species 2015: e.T6909A43792211. http://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T6909A43792211.en. Downloaded on 03 October 2019.
10. J. Sheppard, 2006. Movement heterogeneity of dugongs, Dugong dugon (Müller), over large spatial scales. Journal of Experimental Marine Biology and Ecology. Volume 334, Issue 1, Pages 64-83.
11. B L Chilvers, 2004. Diving behaviour of dugongs, Dugong dugon. Journal of Experimental Marine Biology and Ecology. Vol. 304, Issue 2, pgs. 203-224.
12. L. Aragones, 2010. The Philippine Marine Mammal Strandings from  1998 to 2009: Animals in the Philippines in Peril? Aquatic Mammals, 36(3), 219-233.
13. E. Molina, 2017. Towards the Conservation of Dugongs in Calauit Island, Philippines. Erinamolina.wordpress.com. Last accessed: October 4, 2019.
14. S. Tumampos, 2017. Playing with dugong ‘Aban’ in Calauit. BusinessMirror.com.ph. Last accessed: October 7, 2019.
15. K. Knorovsky, 2018. Where to Swim With the Sea Creatures That Inspired Mermaids. National Geographic. Last accessed: October 4, 2019

Publish date: October 7, 2019.