Dolphins use unique signature whistles that function like personal names, allowing them to identify and address each other individually.

Research from the University of St Andrews, published in the Proceedings of the National Academy of Sciences, confirms that bottlenose dolphins use signature whistles to identify one another. Unlike many animal vocalizations that are genetically inherited, these whistles are learned and individually developed during the dolphin's first few months of life. Each dolphin creates a sound distinctly different from its mother and peers, preventing confusion within the pod.A landmark 2013 study led by Dr. Vincent Janik demonstrated that dolphins respond when hearing their own signature whistle played back to them. This behavior indicates they recognize not just a voice, but a specific acoustic label—a name. This makes dolphins and humans the only known species where individuals use specific sounds to represent personal names for themselves and others.These signature whistles are remarkably persistent and can be remembered for decades. In one study, dolphins recognized the signature whistles of former tank mates after more than 20 years of separation. This sophisticated communication system is essential for maintaining group cohesion in ocean environments where visibility is often limited to just a few meters.The complexity of these vocalizations demonstrates the advanced social intelligence of cetaceans. By using these acoustic names, dolphins coordinate hunting strategies and alert pod members to danger during predator attacks. Scientists believe this level of communication is fundamental to why dolphin societies are so cohesive and successful across diverse marine habitats.