Adelie Penguin Adaptations:

Beak and Mouth and Eyes

The Adelie penguin head adds to its overall fusiform (bullet-like) shape. The strong beak, unlike all other penguin species, is almost completely covered with feathers to conserve heat, and the eyes, when shut, also have a feather covering Besides catching food, Adelie Penguins use their beak to carry rocks to the nesting site and to arrange them into a raised structure (their nest) that will keep the eggs and chicks from either rolling away, or getting wet when rivulets of water form as nearby snow banks melt.
Adelie Penguins catch and swallow their live prey whole. Since they have no teeth, these backward facing spines on this bird’s tongue help keep the prey in its mouth and guide it down the penguin’s throat. The top of the mouth has the same soft spines to help guide the food towards the penguin's stomach.
When an Adelie Penguin is staring straight at you or another penguin or skua, it is not happy about you or the other bird's presence. This is a display called a Direct Stare. It may charge at any minute. If it is only mildly upset about you or another penguin nearby, it will present only half of its face (one eye) toward you, often switching back and forth. This is a less-strong agressive display (Alternate Stare); it won't charge. The eyes of an Adelie Penguin are very expressive. The white 'eye ring' is very important for individual and species recognition. Other penguins do not have such an eye ring, or they have a black one.
This penguin has rolled its eye downward so that its iris is hidden. This penguin is somewhat agitated about a neighbor and will likely go into a display advertising this displeasure even more forcefully.