Giant South American river turtles that live in the Amazon have much more complex social behavior than it was thought until now, wrote biologists in the journal Herpetologica.
During the breeding season the giant river turtles gather in large groups. Until now it was not clear how they coordinate their behavior. Biologists now believe that acoustic signals help them in this.
Scientists have recorded 270 different sounds that the turtles produce on the shore or swimming in the river. After spectrographic analysis, they divided the sounds of six types.
Sounds that turtles exchange, migrating upriver, probably help them to keep in touch witrheachother. Some sounds the turtles produce while choosing a nesting site. In other sounds females communicate with their young. This is the first reported example of how turtles care for their young.
The sounds allowed scientists to determine that small turtles are kept close to the females and migrate down the river with them for two months.
Giant South American river turtles reaches a length of 80 cm. They live only in the Amazon. The species are in danger because the turtles are killed for their meat and eggs.