Bottlenose dolphins are agile, gregarious and highly intelligent animals. They communicate using body movements and sounds, often beyond human perception. They also use a series of clicking noises and then listen for the resulting echoes that bounce off underwater objects. This is called echolocation and allows them to “see” and map their surroundings..

Download the Bottlenose Dolphin Factsheet here

Average size ranges from 1.8 to 4m long and 150 to 200kg in weight, but some can reach more than 650kg. Dolphins living further offshore tend to be larger and fatter with extra blubber to keep them warm in colder waters. They have a long streamlined body and a curved dorsal fin. Their backs are black or dark grey, their flanks and belly slightly lighter. Their distinctive blunt snout or rostrum has given them their name.

BEHAVIOUR

Bottlenose dolphins are social animals and live in schools - family groups made up of a few to more than a thousand individuals. Dolphins of similar sex or age often form and spend time in peer sub-groups. In times of hardship or danger, schools can support and defend each other. In Scotland’s Moray Firth bottlenose dolphins either feed alone or in groups. They can stun fish with sound, use natural and man-made barriers to round-up fish or feed in association with fishermen.

DIET

Bottlenose dolphins feed on fish, squid and other invertebrates, depending on what is available.

LIFE EXPECTANCY

Bottlenose dolphins can live up to 30-50 years in the wild. The life expectancy of dolphins in captivity is reduced as a result of psychological and physiological stress.

DISTRIBUTION RANGE OF BOTTLENOSE DOLPHINS

Bottlenose dolphins live in coastal areas all over the world, from the tropical waters of Australia and Florida to the cooler seas of the UK. Unlike dolphins living further offshore, those living nearer to coastlines tend not to migrate to other areas. In Britain, dolphins are thought to be resident most of the year in the Moray Firth (Scotland), Cardigan Bay (Wales) and off the coasts of Devon and Cornwall (see map below).

The overall population size of bottlenose dolphins around the world is unknown. Extensive long-term monitoring is needed to gather data on population numbers. What is well documented, however, is a growing range of environmental threats prompting widespread concerns over long-term survival of this species and the maintenance of a healthy marine environment on which it depends. Some populations such as those in the Black Sea and Mediterranean are highly endangered.

Bottlenose dolphins in UK waters are protected by law and it is illegal to kill, injure or capture them.

Populations of bottlenose dolphins in British waters are at risk from marine pollution by industrial chemicals and inadequately treated sewage, which can damage their ability to reproduce and fend off diseases. Noise pollution from fishing vessels, underwater explosions and high-powered sonar from seismic exploration or military activities can severely interfere with dolphins' ability to communicate, navigate and find prey. The latter can even be fatal. Overfishing depletes dolphins' prey species and thousands of dolphins drown each year when they are accidentally caught in fishing nets.

In countries outside the UK dolphins are also killed for meat and captured for display in dolphinaria. Climate change and a thinning ozone layer may lead to changes in ocean circulation patterns and affects the marine food chain, representing looming long-term threats to dolphins worldwide.