According to Australian researchers, these cetaceans emit synchronized sounds to form groups and attract females with the greatest potential for mating.
A new discovery made by Australian scientists and published in the Proceedings of the Royal Society B showed that bottlenose dolphins, the most common species of these cetaceans, can coordinate their singing – the first evidence that another animal besides humans, can synchronize using vocal signals. And they do this for a noble reason: to protect females with the potential for mating.
Just as we humans use our voice to march and dance, for example, reinforcing the importance of a group or intimidating our opponents, dolphins also use their sounds to fit into a group and attract females. The behavior was observed in a study done in Shark Bay, Australia, with ethical approval from universities in Western Australia, universities in Zurich, Switzerland and Bristol, in the United Kingdom.
To do this, the researchers used four waterproof microphones behind a speedboat and recorded moments when several males made noises similar to crackles around the females. The sounds echoed at the same time and frequency, in series of two to 49 short noises, 10 per second, repeatedly, forming a kind of singing that can be heard below:
When the males appeared alone, the timing and rhythm of these sounds were no longer the same. According to scientists, this suggests that dolphins use these vocal signals to improve group cooperation and achieve the goal of attracting females.
From this observation, it was found that male dolphins form groups of up to 14 individuals throughout their lives. In subgroups of three, they are always looking for females to be their potential mates. Males keep swimming around the females and making sounds to protect them from other males.
The most important part of the study, according to the researchers, was to discover the existence of this synchronized singing and show how it can help bottlenose dolphins to act – in this case, speak – as one to attract females.