Why do penguins have a white belly and black back?

Penguins have a white belly and a black back as part of a camouflage strategy known as countershading. When viewed from above, their dark backs blend in with the ocean depths, making them less visible to predators like seals and sharks. Conversely, from below, their white bellies match the lighter surface of the water, helping them evade detection by prey. This coloration aids in both hunting and protection from threats in their natural habitat.