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Prix Schläfli (SCNAT)

Giving Turtles a Voice

For a long time, turtles were regarded as largely voiceless creatures. In his dissertation, Gabriel Jorgewich-Cohen has shown that they definitely do communicate acoustically. The postdoctoral researcher at the UZH Department of Paleontology has been awarded the Prix Schläfli in Biology.
Astrid Tomczak-Plewka
Many turtle species thought to be mute actually have a broad and complex acoustic repertoire. (Image: Rafael C.B. Paradero)

His first word was "mummy" and his second was "fish" – that was after he'd discovered a fish pond. "So my father was quite disappointed," Gabriel Jorgewich-Cohen, postdoctoral researcher at the UZH Department of Paleontology, says. He tells this story when asked why he studied biology. "I don't think I had much choice in the matter – it was biology that chose me." He always had a particular interest in reptiles and amphibians. "I kept turtles as pets, and I wanted to learn more about them so I could take better care of them," he recalls. During his studies, however, this Brazilian-born scientist soon realized that the existing research was rather thin on the ground. One reason for this is the limited number of animals: turtles belong to the second smallest group of vertebrates, after crocodiles. "What's more, they are endangered and they're often difficult to access, which is probably why we don't know so much about them."

But Jorgewich-Cohen was not content to settle for that, so he started researching and came across videos of mating land turtles, among other material. "The males make very funny noises," he says. Except for that, however, turtles were considered to be mainly mute creatures that do not communicate vocally. Then Jorgewich-Cohen met researchers who had discovered that aquatic turtles in the Amazon region already make noises as embryos. "I said to myself: that's strange. We see land turtles that make noises, and we see aquatic turtles. But these two representatives of turtles are not closely related. What about all the other species?"

"I couldn't stop smiling!"

Jorgewich-Cohen contacted a sound engineer who developed special underwater microphones for the young biologist. A new world of sound opened up for him. "That was absolutely thrilling," he says. "All of them were making noises, and now I had recordings of a species that had never been recorded before. I couldn't stop smiling!" His delight was nevertheless tinged with uncertainty, because no one had ever done this before.

Animals have been communicating acoustically for over 400 million years

Jorgewich-Cohen was by now a doctoral student at the University of Zurich, although he was working on a different subject. One day, he described his discovery to his supervisor, who put him in touch with a bio-acoustician. One thing led to another: Jorgewich-Cohen travelled to zoos all over Europe and to the Amazon region, where he collected recordings. He ultimately devoted three of the five chapters of his dissertation to his acoustic findings, which question the assumptions of evolutionary biology. Until then, researchers had presumed that acoustic communication in nature had emerged at a fairly late stage, and that it occurred independently in several groups of animals. After Jorgewich-Cohen and other researchers had collected around 1,800 recordings from 53 species, they concluded that acoustic communication has existed for more than 400 million years – in fact, since the emergence of nasal breathing, of which reptiles are also capable. "From an evolutionary perspective, therefore, the sounds of frogs, birds, mammals and turtles are the same," the biologist explains.

Gabriel Jorgewich-Cohen_quote

I don't think I had much choice in the matter – it was biology that chose me.

Gabriel Jorgewich-Cohen

Creativity and enthusiasm

"Gabriel stands out because of his truly creative and pragmatic approaches to original research questions and his healthy ambition, marked by his enthusiastic determination as well as his consideration for others and for the environment," writes Marcelo Sanchez, professor of paleobiology and his supervisor. It almost seems as if Gabriel Jorgewich-Cohen has brought something with him into the adult world that many dream of: a childlike enthusiasm. "My interests are very simple," he says. "I love animals, and I enjoy spending time with them." At first, he couldn't believe that he was being awarded the Prix Schläfli by the Swiss Academy of Sciences for this interest. "I was sitting in the office when I got the news. I yelled out loud," he recalls. "The first thing my colleagues did was give me a Tequila shot."

It's quite possible that the celebration didn't stop at that single shot: Jorgewich-Cohen enjoys meeting up with his friends for drinks. And he is a passionate cook. "It's my favourite hobby at the moment – and I adapt it to each country," he says. "So when I cook Italian food, I also listen to Italian music and maybe wear an Italian football shirt." He used to cook for his family, and now he cooks for his girlfriend. He would like to go back to Brazil again and do more research there – preferably in the Amazon region. "There are so many different animals there – it would be fantastic," he says. He adds that he misses his family and his dog. He is confident that he can put his academic plans into practice, whether in Brazil or elsewhere. "I'm ambitious in the sense that there are certain things that I want to happen. And then I find a way to make them happen." Words that somehow make sense, coming from the mouth of the man who made the sounds of voiceless animals audible.

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