Scientists in Brazil have managed to eavesdrop on underwater "turtle talk".
Their recordings have revealed that, in the nesting season, river turtles appear to exchange information vocally - communicating with each other using at least six different sounds.This included chatter recorded between females and hatchlings.
The researchers say this is the first record of parental care in turtles.
It shows they could be vulnerable to the effects of noise pollution, they warn.
The results, published recently in the Journal Herpetologica, include recordings of the strange turtle talk.
They reveal that the animals may lead much more socially complex lives than previously thought.
The team, including researchers from the Wildlife Conservation Society (WCS) and the National Institute of Amazonian Research carried out their study on the Rio Trombetas in the Amazon between 2009 and 2011.