The speckled brown eggs of seabirds may look like lifeless lumps of shell, but inside, developing chicks are already paying attention to their parents. Researchers studying yellow-legged gull chicks have discovered that the animals can respond to their parents’ alarm calls while in the egg and even pass on the information to younger nestmates by rattling their shells.
The discovery shows that “even before hatching, embryos can use different sources of information – i.e. those coming from their parents but also from their siblings – to prepare themselves for the future,” said Jose Noguera, a behavioral ecologist at the University of Vigo in Spain, who led the new research.
About two miles off the coast of Spain’s northwest corner lays Sálvora Island, part of a national park. The island’s sandy beaches and rocky outcrops make favorable breeding grounds for yellow-legged gulls. But minks and other small carnivores with an appetite ...
