Bottlenose dolphins are the only non-human species known to have names for themselves

Bottlenose dolphins produce individually distinctive signature whistles that broadcast their identity, which they develop through vocal learning by modifying sounds from their environment to create a unique whistle.

These signature whistles are not only used for self-identification but also to maintain group cohesion, and dolphins can even copy each other's whistles, effectively addressing other individuals in their social group with these learned vocal labels independent of the caller's voice features.