The common bottlenose dolphin is one of the most commonly observed dolphins in coastal waters throughout the world. It also maintains large populations offshore, but is not as common as other open water dolphins, such as the short-beaked common dolphin and others.
Coastal populations of common bottlenose dolphins are more territorial and utilize a larger number of coastal habitats – from bays and estuaries to seagrass beds, beaches, and other ecosystems. Oceanic populations are more migratory in nature and apparently do not visit coastal ecosystems.
Common bottlenose dolphins can be quite large, reaching weights of up to 1400 pounds (~640 kg) and lengths of 12.5 feet (~4 m). They are relatively long-lived (40-50 years) and reach sexual maturity at ages between 5 and 14 years old. Some individuals are known to be reproductively active for their entire lives, a rare characteristic among mammals. Like all mammals, common bottlenose dolphins reproduce through internal fertilization, and females give birth to live young. Juveniles are able to swim from the moment they are born, but they are totally dependent on nursing their mothers’ milk for nearly two years.
Common bottlenose dolphins and other dolphins are thought to be some of the smartest animals on the planet, challenging the great apes (chimps and gorillas) for the top spot. They are also extremely curious and often approach people to investigate. Their intelligence is likely both a result of and a driver of their complex social structures. They generally live in small groups and organize complex, group behaviors when mating and hunting. Their preferred prey includes small, schooling fishes and squids. Adult common bottlenose dolphins have no known predators, and juveniles are likely only rarely taken by large sharks or perhaps other predatory marine mammals.
This species is hunted for human consumption and for use as fishing bait in several places around the world, but global numbers are generally considered to be in good shape. Population trends for common bottlenose dolphins are not well known, but scientists believe this dolphin to be a species of least concern. In the United States and some other places, the common bottlenose dolphin is given complete legal protection as a result of it being a highly intelligent, marine mammal.