Unveiling Turtle Talk: Surprising Vocal Abilities in Understudied Species
Paragraph 1
Turtles may never take top place among the animal kingdom’s most prolific vocalizers, but it turns out that they do indeed have something to say. In a new study published in Nature Communications, researchers found that turtles, along with other understudied animals, do in fact communicate using a diverse repertoire of vocal sounds. The study’s authors suggest that their finding may push the origins of acoustic communication back in time to the common ancestor of all lunged vertebrates.
Paragraph 2
Prior to the current study, many of the included species “were considered to be mute,” Gabriel Jorgewich-Cohen, a doctoral candidate at the University of Zurich, tells Scientific American. By listening carefully to recordings from 53 species the team reached a different conclusion: that vocalization is more widespread than previously thought, and that “the sounds that turtles are making have the same evolutionary origin as our own vocal communication,” Jorgewich-Cohen says.
Paragraph 3
The paper’s findings add fresh fuel to debates around the abilities of some animals to communicate with one another. In 2020, two scientists published a paper in Nature Communications in which they mapped the evolutionary phylogenies of roughly 1,800 vocal and non-vocal species and postulated that acoustic communication had evolved independently in Earth’s major lineages (including frogs, birds, and mammals) in association with nocturnal lifestyles. In that analysis, turtles were lumped into the non-vocal group.
Paragraph 4
…Jorgewich-Cohen began to probe for sound in previously understudied species by studying his own pet turtles. “I decided to record them, just to check it out,” he tells New Scientist. “I found several sounds there, and then we just kept going [with more species]. And suddenly, I had good sampling, and I could understand a bigger picture.”
Paragraph 5
From there, the team collected sounds from an additional 50 turtle species, as well as lungfish, tuatara, and caecilians. To better identify which scenarios might elicit sound, Jorgewich-Cohen traveled to five countries to record each species for at least 24 hours, and did so in various settings, including when the animals were alone or in same- or mixed-sex groups, and even when they were underwater. Every species the group studied produced at least one sound, and in many cases, these recordings were the first time such sounds had ever been heard.
Paragraph 6
While the study adds to scientists’ understanding of vocalizations in these groups, it also has implications for the evolution of auditory communications more broadly. When the researchers reanalyzed the earlier phylogenies with their data added in, they concluded that, rather than evolving multiple times, vocalization evolved once in a common ancestor. Specifically, Jorgewich-Cohen and colleagues traced vocalization back to the lobe-finned fish Eoactinistia foreyi, which is considered a possible last common ancestor of all choanate (lunged) vertebrates. That would mean that vocal communication evolved roughly 407 million years ago, at least 100 million years earlier than previously thought.
Paragraph 7
Jorgewich-Cohen tells New Scientist that vocalization may be even older still, as lungless fish also produce sounds. “It could be that one lineage of those fishes was the precursor of the type of sound that we make as [choanates],” he says. “So, it could be actually that this lineage of sound production is older than what I found.”
