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Aug 06 2010

Atlantic Bottlenose Dolphin

paddleboarding by Jamie RoodBY JENNIFER BARBOUR

I regularly hear people say that it never gets old seeing dolphins. What is it that draws us to them? Is it their curiosity of us, their social behavior as mammals of the sea or that permanent friendly smile? One particular summer day, these very feelings were evoked while playing in the Kiawah River. From a distance of nearly 200 yards, we spotted three large adult dolphins charging our way, swimming fast with the falling tide. My guests and I were on paddleboards. As they neared our small group, the dolphins disappeared under the water but decided not to go far. We followed air bubbles made as they zig-zagged all around us, obviously checking out the foreign objects we stood on. They finally surfaced downstream and were on their way to the inlet. Seeing the dolphins so close and witnessing their curious behavior made our trip through the marsh all the more adventuresome.

Along with porpoises, beaked whales and sperm whales, the Atlantic Bottlenose Dolphin (Trusiops turncatus) is a member of the toothed whale family (Odontocetes). They range in length from 6 to 15 feet and weigh in at 300 to 650 pounds. Dolphins have amazing adaptations as marine mammals. Unique features of the lens and cornea of the eye allow them to have acute vision both in and out of water. They also have a sixth sonar-like sense called echolocation. Murky water can make it difficult to detect fish and other objects using eyes alone. Sound waves transmitted from the melon (or forehead) of the dolphin bounce off objects, return to the animal and are then processed through the lower jaw. This means of “seeing” is precise from 1500 yards away!

Females teach their young how to forage efficiently within the tight social structure of a pod. Dolphins work together effectively using their tails to debilitate prey, blow bubble streams to surround and corral fish, utilize underwater creek walls and tidal currents to herd fish, and in the Carolinas, use the mud banks to strand fish out of water for easier capture. This last technique, known as strand feeding, is a remarkable sight since the dolphin typically beaches itself long enough for one to catch a glimpse of its size and strength out of water.

Not too long ago, bottlenose dolphins were hunted for leather, oil, meat and meal for animal feed and fertilizer. Today, US fishing regulations mandate using equipment that aid in preventing dolphins from becoming a by-catch in nets. Unfortunately, these regulations are not observed worldwide – one more reason to buy local seafood! Feeding or swimming with wild dolphins has been illegal in the US since 1990. As a rule, feeding wild animals significantly alters their natural behavior. Fed dolphins typically show more aggression toward humans and other dolphins as a result of being fed. However, you don’t have to feed dolphins in order to get a close encounter with them!

 

Learn more from an expert in the field and experience the bottlenose dolphin in its own habitat. Call the Nature Center at 843-768-6001 for information on guided tours or boat rentals.

About the Author: Jennifer is a Naturalist with the Kiawah Island Nature Program. To contact her with comments, questions, or personal stories, email her at Jennifer_Barbour@kiawahresort.com.

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