Bottlenose dolphins exchange signature whistles when meeting at sea
The bottlenose dolphin, Tursiops truncatus, is one of very few animals that, through vocal learning, can invent novel acoustic signals and copy whistles of conspecifics. Furthermore, receivers can extract identity information from the invented part of whistles.
If signature whistles are the main vehicle to transmit identity information, then dolphins should exchange these whistles in contexts where groups or individuals join.
Scientists found that stereotypic whistle exchanges occurred primarily when groups of dolphins met and joined at sea. Most of the whistles used during joins were signature whistles.
The data show that signature whistle exchanges are a significant part of a greeting sequence that allows dolphins to identify conspecifics when encountering them in the wild.