You are here

Facts about dolphins

Dolphins are incredible. Here are some amazing facts about dolphins and the lives they live in rivers and oceans around the world.
Indo-Pacific bottlenose dolphins
Indo-Pacific bottlenose dolphins

Which is the biggest dolphin?

The biggest dolphin is the orca or killer whale. Others species such as pilot whales and false killer whales are also dolphins as well as the seven species of porpoise.

Which is the smallest dolphin?

In terms of length, the New Zealand dolphin and the vaquita (a species of porpoise) are probably the smallest at about 1.4 metres. However, in terms of weight the finless porpoise probably wins as the lightest cetaceans, reaching a maximum weight of 55kg.  Approximately 3,000 finless porpoises would weigh the same as one blue whale.


New Zealand dolphin
New Zealand dolphin

How long do dolphins live?

In the wild dolphins can live for a long time. Orcas may live for 70 years or more. Bottlenose dolphins can live for at least forty years. Dolphins that are kept in captivity die much earlier than those living in the wild.

Which is the most endangered dolphin?

The vaquita, a species of porpoise, which in Spanish means little cow, is only found in a small area of the northern Gulf of California in Mexico. The species is in dire trouble and the population is estimated to be around 100 individuals. 

The Maui's dolphin (a sub-species of the world’s smallest dolphin - the Hectors dolphin) are found off the North Island of New Zealand and have a population currently numbering approximately 111 individuals. 

River dolphins are amongst the most endangered dolphins as the places they live in are often threatened by human development. The baiji or Yangtze River dolphin, once found in the Yangtze River in China, is unfortunately now classified as extinct. 

Group of Amazon River dolphins swimming together
Group of Amazon River dolphins swimming together

What sounds do dolphins use to communicate?

They use many sounds including clicks, whistles and squeaks.

What is echolocation?

It is the use of sonar to find out where objects are. Dolphins send out sounds and listen to the echo, this tells them exactly what is around them and where their prey is.

Leaping spinner dolphin
Leaping spinner dolphin

Which species undertakes the most marine gymnastics?

The spinner dolphins with their amazing high spinning leaps from the water, put on incredible acrobatic displays.

How long do dolphins live?

In the wild dolphins can live for a long time. Orcas may live for 70 years or more. Bottlenose dolphins can live for at least forty years. Dolphins that are kept in captivity die much earlier than those living in the wild.

Which is the most endangered dolphin?

The vaquita, a species of porpoise, which in Spanish means little cow, is only found in a small area of the northern Gulf of California in Mexico. The species is in dire trouble and the population is estimated to be around 100 individuals. 

The Maui's dolphin (a sub-species of the world’s smallest dolphin - the Hectors dolphin) are found off the North Island of New Zealand and have a population currently numbering approximately 111 individuals. 

River dolphins are amongst the most endangered dolphins as the places they live in are often threatened by human development. The baiji or Yangtze River dolphin, once found in the Yangtze River in China, is unfortunately now classified as extinct. 

Group of Amazon River dolphins swimming together

What sounds do dolphins use to communicate?

They use many sounds including clicks, whistles and squeaks.

What is echolocation?

It is the use of sonar to find out where objects are. Dolphins send out sounds and listen to the echo, this tells them exactly what is around them and where their prey is.

dolphin echolocation

Which species undertakes the most marine gymnastics?

The spinner dolphins with their amazing high spinning leaps from the water, put on incredible acrobatic displays.

What are the differences between a dolphin and a porpoise

The biggest difference is size, with all species of porpoise being that much smaller than their dolphin cousins. Porpoises don't have the pronounced beak that most, but not all dolphins have and they also have a different teeth shape. Porpoise teeth are spade-shaped whilst dolphins are conical.

A dolphin has a hooked or curved dorsal fin (except for those species that don't have a dorsal fin) whereas a porpoise has a more triangular dorsal fin, and generally speaking, dolphin bodies are leaner, whilst porpoises’ are a little more chunky. 

Dolphins are also more "talkative" than porpoises. The whistles made by dolphins are produced through their blowholes and whilst porpoises do not do this, possibly due to structural differences in the porpoise’s blowhole, they can still be pretty noisy as they "puff" the air out when they surface. 

Dolphins and porpoises also have many similarities, one of which is their extreme intelligence. As research evolves, it is likely that more (or perhaps fewer) differences between dolphins and porpoises will be revealed.

Dolphin anatomy