Bottlenose Dolphins

Photo courtesy from HairoftheDawg.rocks

Bottlenose Dolphin (Tursiops truncatus)

Max. Length: 380 centimeters
Max. Weight: 650 kilograms
a value: 0.2754
b value: 2.730
Frequency: Common but prone to fishing by-catch

Being the largest member of the family of beaked dolphins, it is hard to believe that they are also the most playful of all the species of dolphins in Cocos island. While the word “playful” is usually associated with small and agility, the large and robust body of a bottlenose dolphin has the ability to do acrobatic maneuvers. This is due to their powerful tail called fluke that enables their heavy weight body, that can reach up to 650 kilograms, to be tossed completely out of the water.

In Cocos island, you often see them jumping out of the water as if calling you to plunge in and play with them in their vast and protected playground. Again, it is hard to believe that you can go diving and play with a wild creature that is intelligent enough not to harm you. Not unless, they have a certain degree of comprehension for them to know the concept of playing.

Their Brains are larger than Ours

Photo courtesy from plus.google.com

If you want to dig more in to the intelligence of bottlenose dolphins, and other species of dolphins in general, then we might as well focus our attention to the anatomical structure that is responsible for it. Based on studies conducted on the comparison of human and dolphin brains, it revealed that dolphins have larger brains than humans. This just only proves that dolphins can comprehend to a certain degree and that they can be trained.

Dolphin intelligence has allowed them to be placed in civilian and military use. For example, during the post-war era, they have been efficient in locating mines that are set-out at sea and detonation of such explosives has led in minimizing human fatalities. In some areas, they cooperate with fishermen by driving fish towards the net and they get their share through the fish that escapes from it. Before, this was perceived to be a good partnership between dolphins and fishermen. However, as fish stocks are declining and the amount fisherman are harvesting is getting low, this is now perceived as a competition between them.

A Popular Movie Character

Photo courtesy from pinterest.com

Like other marine wildlife, the popularity and intelligence of a bottlenose dolphin has featured them to become a star in various movie films. For the case of bottlenose dolphins, they appear not just once, but in several movie sets. They have also become a popular featured wildlife in nature theme parks.

While this may be good for humans, especially when you see your kids having fun interacting with them in the park, this may not be the real case for bottlenose dolphins. We have to remember that this are wild animals and needs to thrive in their natural environment. Although theme parks are trying their best to mimic the natural conditions of their park facility, it is nothing compared to their wild habitat. This is the reason why marine wildlife in general gets fed-up and do not follow the instructions of park staff and their behavior may turn in for the worst.

Your usual Encounter with Bottlenose Dolphins in Cocos Island

Photo courtesy from Undersea Hunter Group

One of your interactions with bottlenose dolphins in Cocos island is during the arrival of migrating sardines.  This small-sized fish are being chased and cornered by predators, like the bottlenose dolphin, where this large group of fish is compacted in to a size than can be easily devoured. This event is called the baitball where hundreds of bottlenose dolphins converge and join in this shallow water feast.

However, the occurrence of a baitball is not whole year round as it is dependent on the arrival of migratory sardines. Your typical day to day interaction with bottlenose dolphins may not come in hundreds. You usually see them in groups of 10 to 20 individuals that may come in close to the reef. The possibility of mingling with hammerhead sharks and bottlenose dolphins is usually high where both of these species come in for a different reason. While hammerhead sharks come in to visit the cleaning station, bottlenose dolphins may hunt for other schooling fish that thrives near the reef ledge.

Photo courtesy from Conservation International Blog

As we earlier said, they have the tendency to play. If you try to look at the video below, you can see a bottlenose dolphin chasing a trevally. Knowing the swimming speed and agility of a bottlenose dolphin, it could easily devour its prey. However, it prefers to chase it in a “run for your life” challenge until one species succumbs to exhaustion.

On a lighter side, observing bottlenose dolphins doesn’t require you to go diving. In most instances, they follow your liveaboard vessel. They may come in groups of five or more swimming closely on either side of the boat or at the bow. This is their own little way of saying “come and follow me to the beautiful paradise of Cocos island”.

Reference

Sealife Base: www.sealifebase.org

Wikipedia: www.wikipedia.org

Conservation International: blog.conservation.org

Video courtesy from Whitesnake2

About Tristan Paylado
Tristan is a marine biologist and a CMAS 2-Star Dive Instructor
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