Male dolphins use "names" to identify their friends and rivals, Australian researchers have discovered.

A study of 17 adult male bottlenose dolphins in Shark Bay, Western Australia, found they are the only animals apart from humans that give a name to members in their social circle.

Lead researcher Stephanie King, of the Centre of Evolutionary Biology at the University of Western Australia, said using individual names allowed male dolphins to track co-operative partners and competitors and form strong bonds with one another.

The study involved 17 adult male dolphins in Western Australia. (File image) (iStock)

Scientists recorded the dolphins' chatter to identify individual males then checked to see if they all used a unique "word" call when communicating with other males about a dolphin with which they shared a relationship.

The finding is unusual as groups of animals usually make just their calls similar in their social group, as seen in some birds, elephants and primates, Dr King said.

Previous research has shown the dolphins' vocal labels are similar to human names and used to introduce themselves or address specific individuals.

Dr King said male dolphins also used physical displays to show off the strength of their relationships.

"This included petting, stroking and performing synchronous behaviours," Dr King said.

She said the next step would be to study the males' relationships with one another to understand the politics of dolphin alliances and if they were equal or not.