'Talking' Turtles in the Brazilian Amazon 'Sing' to Their Young

It turns out that turtles may be more invested in parental care than previously realized. Scientists have found that Giant South American river turtles use sound in order to stick together and care for their young, using several different kinds of vocal communication.

"These distinctive sounds made by turtles give us unique insights into their behavior, although we don't know what the sounds mean," said Camila Ferrara, one of the researchers, in a news release. "The social behaviors of these reptiles are much more complex than previously thought."

In order to learn a bit more about the Giant South American river turtle, the researchers captured 270 individual sounds between 2009 and 2011. Then, the scientists conducted spectrographic analyses on the sounds, which they then subdivided into six different types of vocalization made by turtles during the nesting season. After, they attempted to correlate vocalizations with specific behaviors.

The researchers found that when turtles were migrating through the river or basking, they tended to make low frequency sounds. Vocalizations during nesting tended to be higher frequency sounds, and the highest density of sounds were used by females about to nest.

What's more interesting is that hatchling turtles make sounds before they hatch and continue to do some as they clamber out of the nest chamber on the beach. The sounds may actually stimulate group hatching. The mother turtles also vocalize in response to the nestling calls to possibly guide the newly hatched turtles into the water.

"Groundbreaking studies such as this one can help us better understand the complex relationships between both individual animals and their environment," said Julie Kunen, one of the researchers. "Protecting the still sizable populations of Giant South American river turtles will also enable us to conserve the behavioral richness of these reptiles for future study."

The findings are published in the journal Herpetologica.