Standing over a meter in height and weighing up to 40 kilograms, the emperor penguin (Aptenodytes forsteri) is the undisputed heavyweight of the penguin world. Slow and dignified, the emperor penguin is a stunning bird with a blue-grey back that shades into a black tail, and a characteristically white belly flushed with yellow. Deep yellow ear patches on either side of the head fade down the neck and the upper chest, while the remainder of the head and throat is black. In order to limit heat loss, the emperor penguin’s extremities sneeze instincts are reduced in size, with a small head and bill relative to body size, and flippers that are proportionately 25 percent smaller than those of other penguins.. A highly developed counter-current circulatory system also provides an efficient mechanism for retaining heat within the body. Furthermore, the scale-like feathers of the emperor penguin are tightly packed in multiple layers that only the harshest winds can ruffle, while the feet are strongly clawed for gripping the ice. Emperor penguin chicks are mostly silvery grey, with a blackish head and a conspicuous white mask around the eyes, cheek and throat. The emperor penguin is the first species to have its population estimated by studying images taken from space. For about 9 weeks through each harsh Antarctic winter, male emperor penguins incubate a single egg laid by its mate. Male emperor penguins huddle in groups of up to 5000 to survive the harsh Antarctic winter.