Why Dolphins Use Vocal Labelling

The idea of animals being assigned names is commonly seen when humans are doing the naming. Not much thought goes into whether or not animals have names for themselves, family members and certain objects. This phenomenon, however, is somewhat observed in bottlenose dolphins (Tursiops truncatus). It has been shown that bottlenose dolphins use vocal labelling. This refers to their tendency to use a specific acoustic signal when faced with certain object. This vocal labelling is used to by the dolphins to communicate to their kin the presence or absence of a particular object. They were also able to create an identity signal, unique to them, in the form of a signature whistle. It is thought that they then address one another by copying this signature whistle.
An experiment was conducted to determine if signature whistling can be used to address individuals. To do this, the signature whistles were recorded and identified with the SIGID (SIGnature IDentification) method. The experiment was conducted on wild dolphins off the east coast of Scotland. Either a synthetic version of the dolphin’s signature whistle, that had just been recorded, would be played back, or a control whistle of an unfamiliar animal from a different pod or a familiar animal from the same population. When faced with the recording of their own signature whistle, the dolphins responded with the same whistle. This rarely occurred when the familiar controls were played and not at all with the unfamiliar controls. The resulting evidence supports the theory that a copy of a signature whistle can be used to label or address specific