Yes, dolphins use signature whistles to represent other dolphins, similar to how humans use names. Each dolphin has a unique signature whistle that it uses to identify itself to other dolphins. These whistles are typically high-pitched and last for a few seconds. Dolphins use their signature whistles to communicate with each other over long distances, to identify each other in groups, and to form social bonds.

Signature whistles are not just simple identifiers, but they also carry information about the dolphin's identity, such as its age, sex, and social status. Researchers have found that dolphins can recognize the signature whistles of other dolphins they are familiar with, even after long periods of separation. This suggests that dolphins have a sophisticated understanding of their social environment and the relationships within it.