As large beasts without particularly powerful senses or any self-defense capabilities, dugongs aren't well-equipped for living in competitive environments. Because of their natural handicaps, these creatures have been forced to adapt to an unkind world, learning how to survive when the odds are seemingly always against them. This combination of behavioral and physical adaptations enables them to go on against the odds.
Like whales and dolphins, dugongs can't breathe underwater, and must surface periodically for oxygen. Unlike those animals, though, dugongs have relatively little lung capacity, and can only hold their breath for about 12 minutes. Because they feed by grazing on plant life on the ocean floor, they have adapted to living in shallow water environments, so they can scour for food more efficiently. They rarely live in deep waters, as they have learned that shallow environments are a better fit for their feeding habits and typically slow swimming.
Navigating the Environment
Dugongs are not blessed with many particularly keen senses, but they have adapted their behavior so that they can more easily find food and navigate the environment. Instead of relying on their poor eyesight to scan the ocean floor, they feel around using their sensitive snouts, which are covered in bristles that can detect underwater grasses. This makes it easier to find food in the murky, turbid waters where dugongs are typically found.
These creatures are not physically adapted for self-defense, so they have learned to adapt their behavior to avoid conflict. Dugongs have historically been targeted by humans for their meat, teeth and other resources, so much so that they are officially classified as a threatened species. Over time, this has taught dugongs to fear and avoid other animals and humans, giving them a shy personality and a hesitancy to approach anything unfamiliar to them.
Dugongs have adapted their communication habits to suit their relatively limited senses, relying on vision and touch when they are near one another and hearing when they are apart. They use their sense of vision mostly when choosing mates, as they perform visual displays to attract each other. The same sensitive bristles on their snouts cover their entire bodies, allowing them to communicate by brushing against each other. When they are separated by distance, dugongs use a variety of sounds like barks and chirps to communicate with each other, so much so that their sense of hearing has become significantly more powerful than their sense of sight.
Tom Ryan is a freelance writer, editor and English tutor. He graduated from the University of Pittsburgh with a degree in English writing, and has also worked as an arts and entertainment reporter with "The Pitt News" and a public relations and advertising copywriter with the Carnegie Library of Pittsburgh.