What type of whistle gives each bottlenose dolphin an individual identity?

A bottlenose dolphin’s individual identity is represented by its signature whistle. Calves develop distinctive whistle patterns that function much like acoustic labels within their social groups.

Researchers have found that dolphins can recognize and respond to the signature whistles of particular companions, even after periods of separation. Dolphins may also imitate another dolphin’s signature whistle, especially during social interactions, which resembles calling that individual by name.

The whistle is not the whole of dolphin communication. Bottlenose dolphins also use clicks for echolocation, burst-pulsed sounds during close interactions, body contact, and visual displays. A signature whistle is specifically associated with identity rather than with every sound made by the animal.

The term is sometimes confused with a general “dolphin language.” Scientists use it more narrowly for a stable, individually distinctive whistle contour. Different populations can show local patterns, but the identity function is the key feature.