The African penguin is a medium-sized penguin, and the only species breeding on the African continent (5). Penguins have a robust, heavyset body and this species are black on the back and white below, with variable black markings on the breast and belly (2). Juvenile plumage is slate blue on the upper surface and this gradually turns darker, developing the adult black-and-white facial pattern in the second or third year. Penguins have small muscles at the base of each feather that enable them to be held tightly against the body whilst in water, forming a waterproof layer; alternatively, on land they are held erect, trapping an insulating layer of air around the body (5). These penguins are also known as 'jackass penguins' due to their loud, braying call (6).