06.09.2018 – Speaking spotted
Our traditional boat had to venture far east today to find cetaceans and we got lucky; a small school of Atlantic spotted dolphins (Stenella frontalis) met us some 2 nautical miles off the coast of Ribeira Brava and charmed our guests with their usual charismatic nature. Dolphins tend to have this magical effect on people and rarely fail to make our guests happy irrespective of how long the encounter may last. The herd we met consisted mainly of adult females with very developed dorsal spot patterns and curious young calves, that spent the majority of the time bowriding our boats waves.
We encounter Atlantic spotted dolphins quite frequently during our tours in the summer months. Amongst the many fascinating facts that I enjoy sharing with the guests during our tours surrounding these small cetaceans I tend to mention one in particular; their bioacoustics. To be fair, I mention it with all dolphins but for me these details have more of a personal depth with this species because I frequently meet them in the water. During snorkeling tours, we aim to encounter these interactive delphinids and, apart from enjoying their presence and being able to admire their entire, impressive physique, such encounters also facilitate the possibility of hearing the animals communicate amongst themselves.
It’s something that is simple to explain but difficult to understand when it come to empathizing with these creatures. Dolphins navigate, orientate themselves, hunt and chitchat using an organ in their head known as the melon. The soundwaves constituting the biosonar are created through compression by muscles above the melon and are modulated according to their use. Dolphins generally use low frequencies while travelling or foraging, emitting soundwaves which can travel dozens of kilometers. To communicate amongst themselves and to scan objects in close vicinity, high frequency soundwaves are generally used.
Research on cetacean acoustics both in captivity and in the wild have shown that these mammals each possess a sort of language. Although this language isnt in any way comparable to human speech, bioacoustic analyses have shown that cetaceans modify their speech according to certain activities using specific sequences of different frequencies. Dolphins „signature whistles“, which are a sort of acoustic fingerprint used for the animals to identify themselves amongst their peers, also help create a unique social dynamic within the schools. Apart from allowing the animals know who they are talking to, it also helps them locate one another which is especially important for mothers and calves. The language spoken using their individual frequencies is something we are still far from understanding.
Interactive species like the spotted dolphins may allow us to gain further insight into the language of cetaceans. Experiments with spotted dolphins in the Bahamas have already borne fruit with impressive results involving two-way communication amongst animals and snorkeling biologists. I for one would love to understand the speech of the spotted. I think understanding dolphins might make us a little smarter.
By Paula Thake
Sightings of the day
13:30 Atlantic spotted dolphins