Scientists have revealed that river turtles in South America use vocal communications to talk to their young ones.
The scientists reveal that certain behavioral patterns of the Giant South American River Turtle, such as gathering in groups have been known to scientists. However, how these creatures coordinate their gathering process is still not clear.
An international team of researchers from the U.S. and Brazil are studying social behavior and communication patterns of the river turtles. The researchers working at the Brazilian Amazon say that they recorded 270 counts of sound during 220 hours of observation.
The scientists used microphones as well as hydrophones to record sounds when turtles were swimming in that part of the Amazon. The researchers reviewed the recordings using spectrographic analysis, which also enabled them to understand the six subdivisions of sounds produced by the turtles and then correlated them to certain social behaviors.
"These distinctive sounds made by turtles give us unique insights into their behavior, although we don't know what the sounds mean. The social behaviors of these reptiles are much more complex than previously thought," says Dr. Camila Ferrara, an Aquatic Turtle Specialist for the Wildlife Conservation Society (WCS) Brazil Program, who is also the author of the study.
Dr. Ferrara and her team reveal that these turtles make low frequency sounds when basking or migrating via the river. The scientists believe that the turtles use the low frequency sounds to communicate over long distances.
The turtle tend to make high frequency sounds while nesting. The researchers say that the reason for producing high frequency sounds is probably because such type of sound travels effectively in shallow water as well as in air.
However, the researchers highlight that they observed diverse sounds produced by females when they prepare to nest. The scientists suggest that it is highly likely that the turtles create various sounds to decide upon a nesting ground and coordinate their movements as they leave for the river together.
However, the grown up river turtles are not the only ones that make sounds. The newly-hatched turtles are also believed to produce sound, which helps coordinate in group hatching as well as in communicating with the female turtles in the river water. The scientists say that the females, who have laid eggs, also produce sounds to communicate and guide the newly-hatched turtles to the river water.
Dr. Ferrara says that once in water, the newly-hatched turtles remain with the grown up female turtles for over two months.
The study has been published in the journal Herpetologica.