Tag Archives: marine mammal

Photo by Smithsonian

Dugongs, Beautiful Sea Cows

Dugongs  are very large, gentle, and super shy marine mammals that are sometimes called “Sea Cows.”  They are light gray in color and can grow up to 4 meters in length and weigh up to 400kg (900lbs). 

We have the very rare opportunity to swim with them in the Maskelyne Islands.  However, let me preface this with a note.  Below are some photos taken from other sources, as noted.  Some of our pictures were fuzzy because the water was murky due to the rain.  But some came out great when the sun came out like this one below.

A Dugong vs. a Manatee

Dugongs are cousins to the freshwater manatee and are similar in appearance and behavior.  Though there are noticeable differences.  Both are related to the elephant, although the giant land animal is not at all similar in appearance or behavior.

Copyright: 2001 Encyclopedia Britannica, Inc.

Copyright: 2001 Encyclopedia Britannica, Inc.

Some other differences:

  • Teeth
    • Dugong: Males have tusk like incisors vs. Manatees: Have regular teeth
  • Lifespan
    • Dugong: 70 years vs. Manatee: 40 years
  • Mating
    • Dugong: Mate for life vs. Manatee: Polygamists, many partners
  • Start Mating
    • Dugong: 10 years old vs. Manatee: 3 years old
  • Birth Rate
    • Dugong: One every 3-5 years vs. Manatee: One every 2-3 years

What do Dugongs Eat?

These enormous vegetarians eat sea grass.  They can be found in warm coastal waters from East Africa to Australia, including the Red Sea, Indian Ocean, and the Pacific.

Most dugongs prefer to eat in areas where seagrass is more sparse rather than lush areas.  They also prefer to eat just the leaves of the grass but when that is limited they will eat the whole plant, including the roots.  Dugongs will dig up the plant and then shake it to remove the sand before eating.

They will dine day and night, rooting with their bristled, sensitive snouts and chomping down with their rough lips.

Dugong Predators 

They have few natural predators, although animals such as crocodiles, killer whales, and sharks pose a threat to the young. 

In the past, dugong meat used to be considered a source of protein, their oil used for cooking and other parts whittled into handicrafts. But now, in Vanuatu, it is considered “tabu” to harm the dugongs and the government is committed to protecting the sea cows and sea grass they eat. 

The next threat to these gentle giants is climate change. Vanuatu is in the “Ring of Fire” and prone to natural disasters which disseminate the shallow sea grass feeding areas. Dugongs are considered endangered in New Caledonia and critically endangered in Africa.

The top left photo is the indent in the sand that a very large male left after he swam away.  The top right is a mama and baby avoiding me. The middle is a mama and baby side by side and the bottom two are another set of mamas and babies.

Dugong Behavior

What we found in Vanuatu was not typical dugong behavior.  Usually they like to be alone or in pairs.  However, we found a herd of at least 10 swimming, playing, and resting in the Maskelyne Islands.

Dugongs are very shy by nature. However, we found them to be a little curious and playful circling back around to swim near Matt and our guide who were free diving.

They can go up to six minutes without breathing, though 2,5 minutes is more typical.  With us it seemed they would go longer than 6 minutes, but then again we were not looking at our clocks to time the duration.

I’ve read that they sometimes breathe by “standing” on their tail with their heads above water.  We never saw this behavior but it would have made for a great photo!

Their eyesight is very poor so the mainly rely on their sense of smell and touch.  They find their food using smell and sense of feeling through their pectoral fins which they use to walk on the sea bed.  Mothers and calves are almost always within touching distance and often reach out to each other with their flippers.

We saw several herds of dugongs which is very unusual.  The first was a herd of 10 and the second was a herd of 6 all at the Maskelyne Islands.  Usually they are swimming in the deeper water making it more difficult to capture photos.

Fun facts

Dugongs have lots of hitch hikers.  These remora attach their heads to the dugong and swim along with them wherever they go, regardless of how fast or slow they are moving.

They always seem to have a smile to give you, no matter how irritated they are with you bothering them.

We met a professional photographer who took these photos a few days before we arrived.  Check out her work at www.mauiph.com

Dugong Tour

We tried to find the sea cows on our own by visiting all of the spots other cruisers had told us about.  But they were elusive.  We would see them from the dinghy, but once we got in the water we could not find them. 

Finally, we tracked down and hired a guide.  Marsel Nathaniel (can be found on Facebook messenger) or at +678.505.7428.  He and his brother Chris came to pick us up (for an additional 500vt/pp ($5/usd) and took us out to see 4 spots.  We found dugongs at 2 of them.  The cost per person was 4000vt/pp ($40/usd) which included the transport.  It was well worth it!

Once we knew where they were at we were able to go back on our own and experience more adventures – which was pure magic!

And this to end our extremely astonishing encounters with the dugongs.  

Our blog posts run 10-12 weeks behind actual live events. We swam with the dugongs in mid-July 2024.  Discover the beauty of the Maskelyne islands in our last blog post.