Image: flickr/Michele W
It's been known for some time that captive dolphins can invent new vocalizations. Although such whistles may be harder for us to pronounce than names like "Flipper" or "Willy", they nonetheless serve many of the same purposes among porpoises. That's because dolphins make up new whistles that other dolphins then use to signal each whistle's inventor. But what happens when dolphins meet for the first time? And what about wild dolphins--do they use "names"? Well, according to this study, the answer to both of those questions is a resounding "yes"! It turns out that when wild dolphins meet at sea, one of the first things they do is introduce themselves using their unique whistles! And so it begins...
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. In captivity, dolphins use such signature whistles while separated from the rest of their group. However, little is known about how they use them at sea. If signature whistles are the main vehicle to transmit identity information, then dolphins should exchange these whistles in contexts where groups or individuals join. We used passive acoustic localization during focal boat follows to observe signature whistle use in the wild. We found that stereotypic whistle exchanges occurred primarily when groups of dolphins met and joined at sea. A sequence analysis verified that most of the whistles used during joins were signature whistles. Whistle matching or copying was not observed in any of the joins. 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." Related content: NCBI ROFL: Phase 1: build an army of land-echolocating dolphins. Phase 2: take over the world. NCBI ROFL: Study proves dolphin tattoos lame. NCBI ROFL: The pyrophysiology and sexuality of dragons.
