River Turtles Found to Communicate Vocally
Over the last year, we have told you about the polite conversation of marmoset monkeys and the translated gestures of chimpanzees. And while animals are evidently capable of communicating with each other in their own way, few appear to do so vocally.
Now, scientists from the WCS (Wildlife Conservation Society) and National Institute of Amazonian Research observing Giant South American River Turtles in Brazil have managed to record vocal communication between the aquatic creatures, finding that they exchange information using at least six unique sounds.
Between 2009 and 2011, the team used microphones and hydrophones – which detect sound waves underwater – to record around 270 individual animal sounds, resulting in 220 hours of recording. This was then analysed and each sound was placed in one of six categories based on the specific behaviour observed when the sound was made. The findings were then published in reptile and amphibian journal Herpetologica.
“These distinctive sounds made by turtles give us insights into their behaviour, although we do not know what the sounds mean,” said WCS aquatic turtle specialist Dr Camila Ferrara.
Dr Ferrara explained that depending on the turtle’s behaviour at the time, the noises it made were subtly different. For example, a specific sound made when adult turtles were migrating through the river was different to when they were gathering in front of river banks containing nest chambers.
And before baby river turtles hatch, they start to make a sound that continues after they have climbed out of their shell and onto the river bank. The team thinks that the sounds these hatchlings make prompt group hatching, which is why all the eggs seems to hatch at around the same time.
The adult females, waiting for their offspring in the water by these river banks, make their own vocal sounds, which the team believes guides the newly-hatched babies from the nesting chamber, over the bank and through the water. Dr Ferrara said that it was possible that the hatchlings might not know where to go if they didn’t have the sounds to follow.
Not only does the research suggest that river turtles lead more socially complex lives than originally thought, but the communication sounds between females and their recently hatched offspring is the first record of turtle parental care, especially when considering that this research led to the discovery that hatchlings and adult females migrate together for at least two months after hatching.
While an exact translation of what the river turtles’ sounds mean has not yet been developed, it has shown that there could be many creatures out there that we didn’t know communicated in this vocal way, just waiting to be recorded.