Brazilian scientists discover that river turtles use sound to stick together and care for the young.

Scientists working in the Brazilian Amazon have discovered that Giant South American river turtles use several different kinds of vocal communication to coordinate their social behaviours. This includes vocal communication between females and hatchings. The scientists say that this is the first instance of recorded parental care in turtles.

The research team includes researchers from the Wildlife Conservation Society (WCS) and the National Institute of Amazonian Research.

Dr Camila Ferrara, Aquatic Turtle Specialist for the WCS Brazil programme, said: "These distinctive sounds made by turtles give us unique insights into their behaviour, although we don't know what the sounds mean. The social behaviours of these reptiles are much more complex than previously thought."

The scientists used underwater microphones and hydrophones to capture nearly 300 individual sounds made during  220 hours of recording while the turtles were swimming through the river. They then analysed the recordings, dividing them into six different types of vocalisation, associating each category with a specific behaviour.

Speaking to BBC News, Dr Camila Ferrara said: "The [exact] meanings aren't clear…but we think they're exchanging information. We think sound helps the animals to synchronise their activities in the nesting season."

The Giant South American river turtle is the largest of the side-necked turtle family and grows up to 80 centimetres in length. The species is only found in the Amazon River basin and is now threatened buy unregulated consumption of the turtles' meat and eggs.

Dr Julie Kunen, Executive Director of WCS's Latin America and the Caribbean Programme, said: "Groundbreaking studies such as this one can help us better understand the complex relationship between both individual animals and the environment. Protecting the still sizeable populations of Giant South American river turtles will also enable us to conserve the behavioural richness of these reptiles for future study."

The study, Sound Communication and Social Behaviour in an Amazonian River Turtle, appears in the journal Herpetolgica.  

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