We all know a friend who came back from vacation with a French accent in their accent. Or noticed an American twang creeping into our voices over dinner with a friend visiting from Texas.
One of us (Luigi) recently moved to Italy from the UK along with four year old daughter Emma who barely spoke Italian. Over the months, she spoke more Italian. But to our surprise, her accent and intonation sounded more like her school friends than her family’s. She stopped trying to sound like her friends. Her voice was like theirs simply because she chatted with them so often.
Our recent study showed that penguins do this too, and that the ability to vary your voice is more widespread across the animal kingdom than scientists thought.
This phenomenon, known as social accommodation, is common among humans. The more two people talk to each other, the more similar aspects of our voices can become. Their voices match. The ability of our voices to change in response to our environment is vital for learning new sounds, words and languages at any age.
The way Luigi’s young daughter’s voice could change quickly and unconsciously made us think whether other animals would do the same.
We study the cognitive abilities of different animals and in recent years Luigi has worked a lot with African penguins. They are an ideal animal for social housing research. 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 constantly communicate with each other, including one that sounds like a braying donkey.
Some animals such as parrots, whales, elephants and bats learn new sounds and songs from their parents, other members of their species, other species wholly or even non-living sources of noise. Blackbirds make an eerie impression of a reversing truck.
The vast majority of animals cannot learn new sounds and are born with a limited number of sounds they can make. However, there is growing evidence that some animals’ calls change in response to who they interact with most and that more animals may vary their sounds than previously thought.
The evolution of African penguins split more than 60 million years ago from all other birds that can learn new callings through observation. Penguins cannot learn new sounds and their vocalizations are genetic.
In our recent study, we analyzed nearly 3,000 penguin calls from three different colonies in zoos in Italy. We first compared the calls of penguins belonging to the same colony, including mates and colony mates, with those of different colonies. Three years later, we also studied the same penguins.
Finally, we compared proximity of calls from partners versus calls from non-partners. 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.
Penguins’ calls were closer to those of their mates three years earlier than those of their colony mates. This may be because of the special relationship between partners. Knowalski, a male in the Zoomarine Roma colony, lost his partner Marietta several years ago and we noticed that he was depressed for a while. Now he boldly tries to steal a female from other males.
Emotions have a huge impact on voice and it can cause some convergence in animals. When partners call each other directly, they may be in a special heightened emotional state, which can affect their voice.
African penguins also use a range of calls in different contexts. For example, a single penguin makes contact calls when they can’t see the colony.
Another study we recently conducted revealed the remarkable cognitive abilities of these seabirds. It showed that penguins can recognize their partner not only by the sound of their voice, but also recognize their partner even when another penguin’s call is played.
We really enjoyed working with these birds. They spend most of their time out of the water and they seem absolutely unfit for dry land. Although they are excellent swimmers, they wiggle so cutely and often fall over their own feet.
Worldwide, we have 18 species of penguins, some with millions of individuals. Others, such as the African penguins, have only a few thousand.
This species is on the IUCN (The International Union for Conservation of Nature) Red List and is classified as endangered. Their world population has declined by 98% since 1900. Quick action is needed to save them.