What do the female emperor penguins return?

Answer 1

They return right before the egg hatches. She finds her mate by a song. The male (now very hungry from lack of eating incubating the egg) turns the newly hatched chick over to the female and goes in search of food. (An Amazing Emperor - Awake 7/22/00)

Answer 2

After laying a single egg, which is passed onto the male to incubate, the female goes off to sea to feed. The female will eventually return after several weeks, usually long after the chick has hatched. It is now the turn of the very hungry male to go off to sea to feed. The Emperor penguin (Aptenodytes forsteri) is the tallest and heaviest of all species of penguin. The egg is placed on top of the male's feet, and a soft belly flap is lowered over the egg to keep the egg warm during incubation.