Dolphins: Delphinidae

Physical characteristics: Common bottlenosed dolphins, also called Atlantic bottlenosed dolphins, range in size from 8 to 12.5 feet (2.5 to 3.8 meters) and in weight from 500 to 1,100 pounds (227 to 500 kilograms). These dolphins can be colored brown to gray on their backs and light gray to white on their bellies. There are several distinct subpopulations in different regions of the world.

Geographic range: These dolphins are found worldwide in warm and temperate, moderate temperature, waters. In the United States they are the most abundant dolphin along the Atlantic coast from Massachusetts to Florida.

Habitat: Common bottlenosed dolphins prefer warm shallow water and are often found along the coast in harbors and bays, although they also inhabit open ocean.

Diet: These animals eat fish, squid, and shrimp. They often feed cooperatively, herding fish together to make them easier to catch. In

Bottlenosed dolphins often ride the waves produced by passing boats. (Tom Brakefield/Bruce Coleman Inc. Reproduced by permission.)

shallow water they may chase fish into a sandbar where they are trapped.

Behavior and reproduction: Common bottlenosed dolphins form pods of varying size. Pods in the open ocean seem to be larger than those close to shore. The pods are moderately stable and tend to migrate in order to follow the fish. Those pods living in cooler waters usually migrate to warmer water in the winter.

Common bottlenosed dolphins are curious and playful. They often ride the waves produced by the passage of a boat through the water. They can jump as high as 16 feet (4.9 meters) out of the water.

Female bottlenosed dolphins have their first calf between the ages of five and twelve years. Pregnancy lasts about twelve months and produces a single calf. Calves stay with their mothers for about three years, after which another calf is born. Bottlenosed dolphins have been successfully born and raised in captivity.

Common bottlenosed dolphins and people: Common bottlenosed dolphins are the dolphins most frequently exhibited in marine park shows. They are very acrobatic and can be taught many behaviors in captivity.

Conservation status: Not enough information is available to give the common bottlenosed dolphin a conservation rating, however, they do not appear to be threatened. The main threat to their habitat is pollution. ∎