"Umph, umph, umph!" That is the cry that Nile crocodiles emit before they are born to communicate to the rest of the offspring and to their mother that the time has come to hatch .
According to Amélie Vergne and Nicolas Mathevon, from the French University Jean Monnet de Saint-Etienne, this communication is critical for the survival of the young reptiles. "We can assume that the timing to hatch the egg may be of vital importance for crocodiles," says Mathevon. "In fact, most deaths occur during the first weeks of life, and the screams from the egg could attract predators," he adds. Therefore, the presence of adults in the nest and their rapid response is essential to protect the newborns. In this sense, "it is important that all embryos are prepared to hatch at the same time and receive equal protection and care from their parents ", the researcher points out.
To reach this conclusion, Vergne and Mathevon carried out a series of experiments with 10 crocodiles and their eggs , recording the sounds that the babies made and then playing them, along with other sounds, for the mothers. "Alligator mothers react strongly to recording calls, most of them digging in the sand," they write in the latest issue of the journal Current Biology . The sound also prompted the brothers to begin breaking their eggs.
