Chelonian vocal communication

Abstract

Recently it was discovered that freshwater turtles communicate underwater by sound. The vocal repertoire of the Western Australian longneck turtle Chelodina colliei includes complex and percussive calls which are harmonically structured and frequency modulated, with dominant frequencies below 1 kHz and a range from around 100 to 3.5 kHz. Sounds with similar characteristics are used by the females of the South American river turtle Podocnemis expansa when migrating to nesting beaches and during communal nesting. Near term embryos inside eggs vocalize, and hatchlings emerging from nests and scampering across the beach and into the river continue to vocalize. In the water the adult females respond and the hatchlings then migrate with the females down the river, presumably to the flooded forests where they feed. Many unexplained aspects of aquatic turtles social behavior may eventually be explained when their vocalizations have been studied.