Just like Gentoo Penguins, Adelie Penguins have to moult their feathers as well. However, as they start their breeding season a couple of weeks earlier, they are also finished earlier. That’s why, at the end of the season, most Adelie Penguin colonies are almost empty, where there are still a lot of moulting adults around in Gentoo Penguin colonies. And those left in the Adelie colonies are a lot further in their moult as the Gentoos are.