Crocodiles speak from within shell

BIOLOGY
The sound is something like laser beams from a 1980s video game, but the voices are baby Nile crocodiles calling out from inside their eggs. By playing recordings of the vocalizations beneath nests, scientists at the Université Jean Monnet and Université Paris-Sud XI in France have confirmed what has long been suspected through anecdotal evidence - baby crocs tell their siblings when it's time to hatch. The sounds also signal their mothers that it's time to dig up the nest to let the babies out and be on the watch for predators. The research may explain why the crocodilian order has a survival rate 10 to 100 times that of all other reptiles, said James Perran Ross, associate scientist in the department of wildlife at the University of Florida, and an expert in the field unaffiliated with the study.

BOTTOM LINE: A study that shows crocodiles make sounds when still inside their shells "confirms, with some rigor, what was previously just anecdotal," Ross said. And it gives a better picture of how complex crocodiles are despite their walnut-sized brains.

CAUTIONS: The researchers only listened to 17 eggs and tested 10 mothers.

WHAT'S NEXT: Ross suggests that researchers turn to the critically endangered Indian gharial, perhaps the last species in the Gavialidae family of crocodilians, to find out if there is a way to use the research to help the long-snouted reptile recover.

WHERE TO FIND IT: Current Biology, June 24. NEIL MUNSHI