That the ability to communicate is not the exclusive patrimony of human beings is not surprising. We know that many other species of animals have complex ways of transmitting information , and sometimes in a completely different way than ours.
Many animals communicate through a mix of sounds and gestures, from rodents to primates to crows. Elephants also use ground vibrations. Dogs, cats, and other animals add scents to their communicative repertoire. Among insects, cockroaches communicate through their faeces, bees do so by ‘dancing’ and ants through the exchange of a pheromone system. Even extending the definition of “communication” enough, it could be said that some plants can communicate, emitting volatile substances into the atmosphere.
communication in cetaceans
Of all living beings, probably the group in which communication has been most studied is the cetaceans . These marine mammals: whales, sperm whales, porpoises, belugas and dolphins have complex communication systems based primarily on sounds and secondarily on body language , whether visual or tactile. Vocalizations stand out in the sound repertoire, which can be in the form of songs, clicks, whistles, and combinations of these, but they can also generate sounds by rubbing their teeth, tapping their jaws, or hitting the surface of the water with their fins. or with the tail.
At first it was thought that these forms of communication were, in a certain way, universal, an innate form that made it easy for any two conspecific specimens, even inhabitants of different regions of the world, to communicate successfully. However, like human languages, although the ability to communicate is innate, the communicative repertoire of cetaceans is an acquired character . The transmission of vocal patterns does not depend on genetic mechanisms, but cultural ones .
The dialects of the killer whales
The logical consequence of this fact is that, since learning processes are never perfect, the repertoire changes over time and evolves in a similar way to what happens with the different human languages. And as a result of this process of cultural evolution, different populations that live far from each other for enough generations, without a cultural exchange between them, end up with different repertoires.
These different repertoires, caused by the geographical isolation between populations and the subsequent differential cultural evolution, have usually been called ‘dialects’ , although the more appropriate term is ‘geographical variations’ .
Its presence has been observed in several species of cetaceans, where the sperm whale and pilot whale stand out, and also in pinnipeds —mainly in the common seal and the Weddell seal—, but perhaps the most representative of all is the killer whale .
Orca calves learn vocalizations first from their mother and second from their social group, especially close maternal relatives. The cultural evolution observed in killer whale dialects is extraordinarily complex. Not only random errors are included in the learning of sounds, fixed through generations, but also a horizontal cultural transmission between different lineages that, from time to time, can come into contact, in a phenomenon analogous to what we call ‘linguistic loans’ in human languages.
learning to speak with dolphins
This horizontal cultural transfer that modifies the dialects of the populations also shows the great plasticity of killer whales in their ability to communicate. And this plasticity has come to break down barriers in a totally unexpected way.
Killer whales are not only capable of acquiring dialectal traits typical of other populations of the same species and incorporating them into their dialect, but they can also acquire communicative traits of other species.
In 2014, a research group led by Whitney B. Musser of the University of San Diego, California, analyzed the repertoires of three killer whales that had had prolonged contact with bottlenose dolphins and compared them to those of seven killer whales that had never had contact. with dolphins —as a control group— and with those of nine bottlenose dolphins. These killer whales were found to have acquired several dolphin sounds and incorporated them into their repertoire.
This fact proves that killer whales present contextual learning and a great motivation to favor communication with other populations and even with other species, a phenomenon associated with strong social and cultural cohesion , and with behaviors related to collaboration.
References:
Ford, JKB 2018. Dialects. In Encyclopedia of Marine Mammals (pp. 253-254).
Elsevier. DOI: 10.1016/B978-0-12-804327-1.00104-7
Ford, J. K. B. 2019. Killer Whales: Behavior, Social Organization, and Ecology of the Oceans’ Apex Predators. En B. Würsig (Ed.), Ethology and Behavioral Ecology of Odontocetes (pp. 239-259). Springer International Publishing.
DOI: 10.1007/978-3-030-16663-2_11
Musser, W. B. et al. 2014. Differences in acoustic features of vocalizations produced by killer whales cross-socialized with bottlenose dolphins. The Journal of the Acoustical Society of America, 136(4), 1990-2002. DOI: 10.1121/1.4893906
Van Cise, A. M. et al. 2018. Song of my people: dialect differences among sympatric social groups of short-finned pilot whales in Hawai’i. Behavioral Ecology and Sociobiology, 72(12), 193. DOI: 10.1007/s00265-018-2596-1
