In the Antarctic winter, the Adélie penguins live at sea. Both parents care for the eggs. While one stays behind keeping the eggs warm and safe from predators, the other parent heads out to sea to eat. They feast mainly on krill, tiny shrimplike animals, but also eat fish and squid.
Parents take turns caring for their youngsters after they hatch until the chicks are about three weeks old. At that point, both parents may leave to forage for food while the chicks gather in the safety of a large group of other young penguins. These groups of young Adélies are called crèches.
By March, when Adélie chicks are about nine weeks old, their downy baby feathers have been replaced by waterproof adult feathers. They plunge into the sea, and start hunting for food on their own.
Like other penguin species, Adélies are excellent swimmers. They're powerful and graceful in the water, with torpedo-shaped bodies that pierce through the water. Their modified wings help propel them through water instead of air. These birds are swimmers, not fliers.