Vincent Janik, Tuesday April 26
COMPLEXITY AND MEANING IN MARINE MAMMAL COMMUNICATION
University of St. Andrews, UK
One of the most significant steps in the evolution of complexity in acoustic communication was the acquisition of vocal learning skills. Vocal learning in the sense of copying novel sounds is rare in mammals and only occurs in humans, marine mammals, elephants and bats. The seemingly most convincing evidence for vocal learning comes from animals copying human speech. However, this can be misleading if calls in their natural repertoire resemble human utterances. We have developed a training method that allows testing vocal learning skills more objectively by using existing sounds in the animal’s repertoire as a starting point before progressing to artificial stimuli. Using this method, we could demonstrate vocal learning of formants in grey seals, and quantify vocal learning abilities in bottlenose dolphins. While the necessity for vocal learning in grey seals is a little unclear, bottlenose dolphins use these skills in the development and copying of signature whistles. These whistles are individual identification calls and are used when animals meet at sea or are trying to stay together. Each animal develops its own unique signature whistle early in life. The fundamental frequency modulation pattern of this whistle does not correlate with size, age, sex or relatedness, making it a relatively arbitrary signal. Signature whistles are produced in a specific temporal delivery pattern that makes them recognisable as signatures. Other animals occasionally copy signature whistles and can use this copying to address the whistle owner. Copying events in interactions occur in a specific time window after the owner produced a whistle, but dolphins also copy signature whistles of absent animals, most likely in an attempt to make contact. Signature whistles are potentially referential when copied by others, but further tests are necessary to fully explore the use of reference in marine mammal communication. Marine mammals show a remarkable range of cognitive skills affecting their communication, but most data come from artificial tests in captive settings. The exploration of how animals use these skills in their own communication system is still in its infancy but revealed patterns that highlight the role of vocal complexity in social interactions.
- Where and when:
16:30-17:45 Apr 26, 2016MPI Conference room 163
- Shiri Lev-Ari