Ornate Wood Turtle (Rhinoclemmys pulcherrima) Photo by Tornadohalt, CC BY-SA 3.0 <http://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons

Dear Readers, the whole idea of ‘dumb animals’, which was always a bit dubious as far as I’m concerned, has been thrown into even greater doubt following the discovery that over 58 species of animals that were thought not to communicate with one another do, in fact, chat away to one another.

Many vertebrate animals with lungs are known to be able to produce sound by forcing air up and through structures in their throats. However, scientists thought that many of the sounds were either produced accidentally, or in extremis – wailing because you’re being eaten by a crocodile doesn’t count as communication, apparently. Turtles in particular were thought to lead quiet lives.

Fortunately, scientist Gabriel Jorgewich-Cohen of the University of Zurich was curious about this idea, and he started by paying close attention to his pet turtles.

“I decided to record them, just to check it out,” he says. “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.”

And what a bigger picture it is! Turtles, the Australian tuatara and even a species of lungfish ‘talk’ – circumstances differ, but include parental care, mate selection, and marking territory. The most garrulous communicators are apparently males when fighting other males or when they are trying to woo a partner. I am resisting the urge to make any comparisons with any other species.

A Talkative Tuatara (Not a lizard!) (Photo by By Sid Mosdell from New Zealand – Tuatara, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=70735190

And how about this critter? ‘What the hell is that?’ I hear you cry. This is a Cayenne Caecilian (Typhlonectes compressicauda), a kind of amphibian which lives in muddy water, and which has no functional eyes. No wonder sound is more important to this animal than was thought. It’s thought to detect its prey by touch or by vibration, but if it can communicate vocally presumably it can also hear. Fascinating stuff.

A Cayenne Caecilian (Photo By User:Haplochromis – Self-photographed, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=3037073)

And finally, and in a way most extraordinarily, this lungfish has also been found to communicate vocally. The South American lungfish lives in the swampy regions of the Amazon, and, in the breeding season, the parents work together to build a nest. The male develops special fins at this time which he waves to oxygenate the water so that the eggs and young fish can breathe. Once hatched, the youngsters are said to resemble tadpoles. With this degree of parental care, it’s not surprising (to me anyway) that the species is able to communicate vocally, especially as muddy water would make anything else difficult.

South American lungfish (Lepidosiren paradoxa) Photo Vassil, CC0, via Wikimedia Commons

What is particularly interesting is that this means that the ability to communicate vocally evolved way earlier than scientists previously thought – at least 407 million years ago. As most fish don’t have lungs, and it’s known that they can produce a wide variety of sounds, it probably goes back even further than that. Clearly, vocal communication has been part of the lives of animals pretty much since they came into existence.

You can read the whole article here.

And of course, I couldn’t leave this subject without including some examples of the vocalisations of these ‘mute’ creatures – you can have a listen here. Enjoy!