The distinctive bottle-shaped snout gives these dolphins their name
Where do they live?
Bottlenose dolphins live in temperate and tropical seas all over the world. There is an inshore species that is often seen along the coast, in estuaries and even in rivers, and an offshore species that can be found in the open ocean.
What do they eat and how?
Bottlenose dolphins eat around 15 kilograms of food per day consisting of a wide variety of fish, squid and octopuses. The offshore form may be able to dive to depths of more than 600 metres to catch food. Dolphins use echolocation for hunting and navigating. The clicking sounds they make travel through the water hitting objects up to 200 metres in front and echoing back to the dolphin, which allows them to work out the size, shape, speed, distance and direction of their prey. Working together as a group, dolphins can trap schools of fish or squid by rounding them up and diving into the middle to feed, swallowing their food whole and head first.
Predators and threats
Natural predators include killer whales and sharks such as tiger sharks and dusky sharks. Other risks include entanglement in fishing nets (trawling, drift and gill nets), habitat destruction and degradation, pollution (organochlorines), disease (Morbillivirus) and illegal killing of dolphins. In some parts of the world bottlenose dolphins are killed for food. It is also possible that the dolphins' key prey species are being fished out, thus reducing the amount of food available to them. In Perth and particularly around Rockingham local dolphins have taken to begging for food from local boats. This has led to an increase in mortality from propeller strikes and fishing line entanglement as well as a reduction in reproductive success.
Bottlenose dolphins are very social animals that live together in parties. Inshore parties may have around 12 members and offshore parties may number in the hundreds. Within the party there is a strong sense of unity or bonding, with lots of interaction between the dolphins in the group (touching, chasing, making noises etc). Bottlenose dolphins are highly active and can be frequently seen tail slapping, riding on bow waves created by boats, surfing waves or leaping playfully into the air. They will chase one another, roll over each other and carry objects such as seaweed.
Breeding and raising their young
Dolphins have many partners over a lifetime and mate all year round. Females begin to breed from about six years of age, and have a calf every two to three years. Calves are born throughout the year, although most are born in spring and summer after a gestation period of 12 months. Calves are born tail first so that they do not drown and their mother quickly pushes them up to the surface for their first breath. Calves suckle their mother's milk for up to 18 months, although they begin eating fish at about 6 months of age and remain with their mother for about six years.
The bottlenose dolphin is common throughout the world’s oceans.
How you can protect the bottlenose dolphin?
You can care for them by helping to keep their environment clean. Take your rubbish home, and if you find any floating at sea or on the coast, please pick it up. Bottlenose dolphins often strand, either singly or in small groups. If you find a stranded or entangled dolphin you should report it to the Department of Environment and Conservation. While you are waiting for help to arrive, keep it wet and cool, and keep it shaded so it doesn't get sunburnt, but remember not to obstruct the blowhole, so the dolphin can breathe.
Find out more about keeping Perth’s dolphins wild