Penguins have feathers, not fur

The fact that penguins have feathers rather than fur is one of the reasons they can endure extremely cold climates. Because penguin feathers are such effective insulators, the birds have more trouble staying cool than getting warm.

In addition to their incredible insulating capacities, penguin feathers have several other extraordinary qualities. They are also icephobic, which means that they repel ice. They can therefore dive into and out of frigid water, be soaked by ocean waves, and do so without developing frozen patches on their feathers. This means that the larger-scale and microscopic structure of the feathers, as well as a special oil secreted by the animal itself and distributed over its feathers, prevent ice from getting on them. Scientists who have studied the ice-repelling feathers believe that this feat is due to three characteristics: "a unique combination of the feather's macroscopic structure, the nanoscale topography of its barbules, and the hydrophobicity of its preen oil."

Every year, penguins molt, as do other birds. When an animal molts, its old, worn-out feathers are shed and replaced by brand-new ones. However, penguins molt far more quickly than other birds, taking anything from 2 to 5 weeks. Due to their abrupt molt, which entails their marooning on the coast while they fast and lose their feathers, scientists have been tracking king penguins. When their feathers come in, chicks must regain the weight they lost, which includes practically all of their fat and part of their muscle.