Dolphins

Feeding:Dolphins are predators, chasing their prey at high speed. The dentition is adapted to their prey: Species with long beaks and many teeth forage on fish, whereas short beaks and lesser tooth count are linked to catching squid. Some dolphins may take crustaceans. Usually, the prey is swallowed whole. The larger species, especially the Orca, are capable of eating other marine mammals, including other whales. There are no known reports of cannibalism amongst dolphins.
Individual species may employ a number of methods of hunting. One such method is herding, where a superpod will control a school of fish while individual members take turns plowing through the herd, feeding. The tightly packed school of fish is commonly known as bait ball. Coralling is a method where fish are chased to shallow water where they are more easily captured. In South Carolina, coastal Bottlenose Dolphins take this one step further with what has become known as mudding, where the fish are driven onto mud banks and retrieved from there. In some places, Orcas will also come up to the beach to capture Seals. Some species also whack fish with their fluke, stunning them and sometimes sending fish clear out of the water.
Dolphins often leap above the water surface, sometimes performing acrobatic figures (e.g. the spinner dolphin). Scientists are not quite certain about the purpose of this behavior, but it may be to locate schools of fish by looking at above-water signs, like feeding birds. They could also be communicating to other dolphins to join a hunt, attempting to dislodge parasites, or simply doing it for fun. Play is a very important part of dolphins' lives, and they can often be observed playing with seaweed or play-fighting with other dolphins. They even harass other locals, like seabirds and turtles. Dolphins also seem to enjoy riding waves and frequently 'surf' coastal swells and the bow waves of boats.

Dolphins are social, living in pods (also called "schools") of up to a dozen individuals. In places with a high abundance of food, pods can join temporarily, forming an aggregation called a superpod; such groupings may exceed a thousand dolphins. The individuals communicate using a variety of clicks, whistles and other vocalizations. They also use ultrasonic sounds for echolocation. Membership in pods is not rigid; interchange is common. However, the cetaceans can establish strong bonds between each other. This leads to them staying with injured or ill individuals for support.
Because of their capacity for learning, dolphins have been employed by humans for any number of purposes. Dolphins trained to perform in front of an audience have become a favorite attraction in dolphinaria, for example SeaWorld. Such places may sometimes also provide an opportunity for humans to interact very closely with dolphins. Dolphin-human interaction is also employed in a curative sense at places where dolphins work with autistic or otherwise disabled human children. The military has employed dolphins for various purposes from finding mines to rescuing lost or trapped humans. Such military dolphins, however, drew scrutiny during the Vietnam War when rumors circulated that dolphins were being trained to kill Vietnamese skin divers. Reports of cooperative human-dolphin fisheries date back to Pliny. A modern human-dolphin fishery was reported in Laguna, Santa Catarina, Brazil in 1990.

special features

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Dolphins are aquatic mammals that are closely related to whales and porpoises. There

are almost forty species of dolphin in seventeen genera. They vary in size from 1.2 m (4

ft) and 40 kg (88 lb) (Maui's Dolphin), up to 9.5 m (30 ft) and ten tonnes (the Orca). They

are found worldwide, mostly in the shallower seas of the continental shelves, and are

carnivores, mostly eating fish and squid. The family Delphinidae is the largest in the

Cetacea, and relatively recent: dolphins evolved about ten million years ago, during the

Miocene. Dolphins are considered to be amongst the most intelligent of animals and

their often friendly appearance and seemingly playful attitude have made them popular in

human culture.