'Language' of seal pups more similar to humans than thought
Each day, de Reus used a microphone to record the calls of 64 pups for ten to 15 minutes
The communication system of common seal pups is more similar to humans than was thought. For instance, they take turns while "talking" and their calls become increasingly similar as they spend time together. This is according to research by biologist Koen de Reus (affiliated with the Max Planck Institute), who will receive his PhD on the subject on 20 February from the Free University of Brussels (VUB) and Radboud University in Nijmegen. For the study, he and his colleagues recorded more than 1,000 hours of audio material from seal pups in Pieterburen (Nl).
Only a handful of animals can 'vocally learn', meaning they can learn new sounds or modify their sounds. "Humans can of course do that, for example when learning a new language", says de Reus. "Furthermore, dolphins, songbirds and real seals, among others, can also learn vocally." Seals are mammals just like humans, which makes them particularly interesting for comparative research on vocal learning. "There is of course a lot of difference between seals and humans, but in the way they communicate, there are similarities", he says.
For his research, the biologist recorded at Pieterburen Seal Centre (now located at WEC Lauwersoog) the sound of the calls of seal pups that were temporarily sheltered there to recuperate. Each day, he used a microphone to record ten to 15 minutes of calling at 64 pups. "In the wild, pups call out for their mother, for example when they are hungry or distant from each other", he said.
Each call of each pup has unique sounds, a kind of vocal signature, that their mother can recognise soon after birth. This comes in handy when the mothers return from hunting and can't find their pups on the beach. "After all those hours with the pups, I could also recognise at least half the calls," laughs de Reus.
The calls of the pups sitting near each other at the shelter are becoming more and more similar," the study found. It is said to be similar to regional accents in human language. During an experiment in which he played calls from pups over a speaker, De Reus noticed that the seal pups waited each other's turn. "So just like in humans, they wait for the other person to finish talking," he said. Seals seem to be much more social animals than we thought."
The results may help to learn something about the evolution of language, not only of seals, but also of humans. "People always think that language is what distinguishes us from animals," says de Reus. "I wanted my research to show that we are not so unique at all: every animal has its own communication system, with certain features of those systems being similar. By comparing, we can learn something about the evolution of such a system, including our own. With my research, I hope I have laid a foundation for doing just that."
More information
Koen de Reus: Koen.De.Reus@vub.be
