The Song Before Hatching

In 2012, researchers at Flinders University in Adelaide, Australia, made a remarkable discovery about superb fairy-wrens. These tiny, iridescent birds sing a unique melody to their eggs — days before the chicks hatch. Dr. Sonia Kleindorfer and her team found that each mother fairy-wren teaches her unborn offspring a specific "password" call, a signature note embedded deep in their memory before they ever crack the shell.…