#rp057

Previous sound recordings of resident (fish-eating) killer whale groups have revealed matrilineal groupspecific call repertoires and a strong tendency for calls of the same type to be produced in series. Vocal interactions between individual free-ranging animals, however, have remained unexplored because it has not been possible to identify signallers reliably with a single hydrophone. Here we link acoustic arrivals of calls on a towed hydrophone array with visual tracking of photo-identified individuals to ascribe calls to a focal animal when it was separated from other members of its matrilineal group by more than 35 m, and thereby out of visual range.