Identifying Turtles and Cavecilians that aren’t Velocity-Triggered by the Sound of a Turtle and an amphibian

The sounds made by 53 species were identified in a new study. Fifty of the species were turtles, with tuataras (a kind of reptile found in New Zealand), caecilians (a limbless amphibian), and the South American lungfish rounding out the group.

Want to listen to the evidence? Here’s the sound of a turtle. And here’s a caecilian, a limbless amphibian that lives hidden underground.

The project was on. He traveled to eight or nine institutions in five countries, on a quest to record animal species that were thought mostly to be mute. He recorded fifty species of turtles, as well as caecilians, tuataras (a reptile that’s now found only in New Zealand), and lungfish (fish that can breathe air).

“Sometimes it’s surprising how much we still don’t know about things that aren’t necessarily uncommon but live alongside us,” says Neil Kelley, a paleontologist at Vanderbilt University.

Kelley says the paper’s conclusion, mapping these vocalizations onto the evolutionary tree, make sense. He said that trying to listen to animal sounds for millions of years was challenging.

There are differences between sound production and hearing. Snakes are well known for their hissing sounds. But they aren’t thought to be able to hear themselves — or each other — hissing.

And a turtle making sounds doesn’t necessarily mean that it is communicating that way, says John Wiens, professor of ecology and evolutionary biology at the University of Arizona.

The team doesn’t know what all the sounds they collected mean but they used several tricks to find out such as using cameras and repeating sounds that could show intent.

Hearing the mother turtles calling to their young made Jorgewich-Cohen “super interested” in identifying more turtle noises, he said. I thought there might be more turtles making sounds.

The idea grew into a bigger project. “The idea was to focus on animals that are commonly, historically considered to be nonvocal,” he said. I wanted to report these animals that are unknown to vocalize and try to understand what is happening in the big picture.

He was talking with a New Zealand reptile specialist who said she heard the animals making sounds during her fieldwork. The research used audio recordings to document the distinctive vocalizations of the tuatara.

The sounds made by caecilians were especially unexpected, he said. “I was very surprised to discover they do produce sounds often, and in a very funny way,” he said. The caecilian recordings sound at times like purring, and at others like a loud burp.

But the extended evolutionary family tree constructed by Jorgewich-Cohen’s research team suggests that the ability to produce sounds “comes from one single origin,” he said. The paper claims that vocal communication must be as old as the last common ancestor of choanate vertebrates (vertebrates with lungs), approximately 407 million years old.

In addition to recording 53 species themselves, Jorgewich-Cohen and his team also used an acoustic communication dataset published by University of Arizona professor of ecology and evolutionary biology John Wiens and Zhuo Chen in Nature Communications in 2020.

Further research is necessary to establish the origins of vocal communication, according to Wiens.

And the criteria for what the scientists identified as acoustic communication weren’t clear, he said. It’s hard to tell if they’re making sounds or not in some cases.