When she’s ready to lay an egg ... the birds’ behavior in 2014 in Amsterdam, where she lives. “The poor warbler almost disappears in the wide-opened mouth of its ‘adopted’ baby ...

Chicks preparing to hatch tuck their head under their ... “This little prenatal dinosaur looks just like a baby bird curled in its egg, which is yet more evidence that many features ...

A fossilized dinosaur egg ... their bird descendants. The embryo’s position mirrors the “tucking” behavior seen in modern bird embryos, a vital adaptation for successful hatching. Its ...