Learning speech by listening, imitating and making new vocal sounds is something humans do from infancy. A sense of rhythm is also linked to both our speech and to how we create and enjoy music.
Our closest primate relatives don’t have such a strong combination of these abilities. But harbour seals – also good vocal learners – seem to have what it takes on both counts, reports Biology Letters.
To uncover this, lead author Laura Verga and her team played back different seal pup sounds to 20 wild-born, untrained youngsters in the Dutch Sealcentre in Pieterburen. Calls varied in tempo, length and how they were arranged in long sequences.
Based on how long and often they looked back at a speaker during playback, the seals had clear preferences. Their taste was for fast tempo over slow, long calls rather than short and for regular rhythm.
Next question, says Laura, is to ask: “Are seals special, or are other mammals capable of spontaneously perceiving rhythm?”
What are harbour seals?
Harbour seals (Phoca vitulina) are sometimes known as common seals, and are marine mammals found in the Northern Hemisphere, including around the coasts of the UK.
Harbour seals eat a variety of fish and other marine animals, including herring, shrimps and squid. Despite the alternative name of common seal, it is outnumbered in British waters by the grey seal. In Ireland, the two are closer in number.
Main image: A harbour seal resting on seaweed-covered rocks in Portree, UK. © Sam Spilsbury/Getty