The female and male penguin’s first bond and then mate to lay an egg the size of a softball on the ice in midwinter. The male thrusts the egg up onto his feet, where it is protected and cushioned by the male’s “brood patch,” a warm fold of feathers and his bulging stomach which rests atop the feet. The egg remains in that place for 9 weeks until it hatches during the coldest months of the Antarctic winter.
Both female and male penguins protect their eggs and newly hatched chicks by enveloping them under a fold of body skin. During the reproductive cycle of the first part the mother penguin has to fast, but after eggs are laid, they go away to fatten them.