We’ve all known a friend who came back from holiday with a French lilt in their accent. Or noticed an American twang creeping into our voices during dinner with a friend visiting from Texas.
One of us (Luigi) recently moved back to Italy from the UK, with our four year old daughter Emma who barely spoke Italian. Over the months she spoke more in Italian. But to our surprise, her accent and intonation sounded like her school friends instead of her family. She tried not to sound more like her friends. Her voice became similar to theirs simply as a result of talking to them so often.
Our recent study showed that penguins do this too, and that the ability to vary your voice is more widespread in the animal kingdom than scientists thought.
This phenomenon, known as social accommodation, is common in humans. The more two people talk to each other, the more similar the sides of our voices can become. Their voices echo each other. The ability of the voice to change in response to our environment is essential for learning new sounds, words and languages at all ages.
The way Luigi’s young daughter’s voice could change quickly and unconsciously made us wonder if other animals do the same.
We study the cognitive abilities of a variety of animals, and in the last couple of years Luigi has been working a lot with African penguins. They are an ideal animal for researching social accommodation. African penguins form large colonies and have different types of relationships (with partners, colony mates). They also have a variety of calls that they use to communicate with each other all the time, including one that sounds like a donkey.
Some animals such as parrots, whales, elephants and bats learn new sounds and songs from their parents, other members of their species, completely different species or even non-living noise sources. Blackbirds do an uncanny impression of a truck backing up.
The vast majority of animals cannot learn new sounds and are born with a limited range of sounds they can make. However, increasing evidence suggests that some animals’ calls change in response to who they interact with the most, and that more animals can vary their sounds than previously thought.
African penguins’ evolution split more than 60 million years ago from all other birds that can learn new calls by observation. Penguins cannot learn new sounds and their vocalizations are genetically determined.
In our recent study, we analyzed almost three thousand penguin calls from three different colonies in zoos around Italy. We first compared the calls of penguins belonging to the same colony, including partners and colony mates, with those from different colonies. We also studied the same penguins three years later.
Finally, we compared the closeness of partners’ versus non-partners’ calls. In all cases, we found that penguins who heard each other’s calls more often had similar “voices”.
Our study suggests that the more penguins experience each other’s calls, the more similar their calls become. And it shows that even animals incapable of vocal learning can have flexible acoustics.
The penguins’ calls were closer to their partners than to their colony mates three years earlier. This may be due to the special relationship between partners. Knowalski, a male in the Zoomarine Roma colony, lost his partner Marietta a few years ago and we noticed that he was depressed for a while. Now he brazenly tries to steal a female from other males.
Emotions have a huge impact on voice, and it can lead to some convergence in animals. When partners are on the phone with each other directly, they may be in a particularly heightened emotional state, which may affect their voices.
African penguins also use a variety of calls in different contexts. For example, a penguin calls when they cannot see the colony.
Another study we recently conducted highlighted the remarkable cognitive skills of these seabirds. It showed that penguins can not only recognize their partner from the sound of their voice, but can also recognize their partner by sight even when the cry of another penguin is played.
We have really enjoyed working with these birds. They spend most of their time out of the water, and they certainly seem unsuitable for dry land. Although they are good swimmers, they wobble so cutely and often fall over their own feet.
Worldwide, we have 18 species of penguins, some with millions of individuals. Others, like the African penguins, have only a few thousand.
This species is on the red list of the IUCN (The International Union for Conservation of Nature) and classified as endangered. Their world population has declined by 98% since 1900. Urgent action is needed to save them.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
Luigi Baciadonna works for the University of Turin.
email@example.com works for the University of Turin.