Recent research published in the Journal of the Acoustical Society of America suggests killer whales (Orcinus orca) are able to learn the vocalizations of other species. The study analyzed a total of 1551 killer whale vocalizations produced in a variety of contexts. Killer whales were kept in separate facilities with a varying number of bottlenose dolphins, which resulted in different vocal patterns within the whales.

Both odontocete species appear to demonstrate complex vocalizations, but their ability to learn, the loyalty of these imitations, and the types of social situations that promote matching are still poorly understood.

Cross-fostering one species with another and observing the changes in vocalizations is one clever way in which researchers shed light on how non-human mammals learn language.

Within their own species, groups of killer whales maintain unique pulsed-call repertoires, called ‘dialects’. Little is known about how mammals learn to imitate vocal calling, but it remains an area in which researchers can further understand learning and neural plasticity. Vocal imitation is assumed when an animal hears a sound and later produces a sound with similar acoustic features. If the two calls are associated in time, the behavior is further defined as vocal matching.

“There’s been an idea for a long time that killer whales learn their dialect, but it isn’t enough to say they all have different dialects so therefore they learn. There needs to be some experimental proof so you can say how well they learn and what context promotes learning,” said Hubbs-SeaWorld Research Institute senior research scientist Ann Bowles, reported by Headlines & Global News.

Killer whale vocalizations are classified as clicks, pulsed calls, and whistles, similar to bottlenose dolphins. For social communication, bottlenose dolphins predominantly produce whistles while killer whales produce pulsed calls.

One killer whale in the study was observed to imitate a vocal pattern of a bottlenose dolphin that was taught by humans, thus a novel series of chirps was introduced in killer whales.