At the southernmost part of the planet, the ice-covered continent of Antarctica is a frozen and seemingly inhospitable place, with whipping winds and an average temperature of just about -50°C (-58°F). Due to its remote location and harsh environment, there are no permanent human inhabitants; the only people on the continent are visiting research scientists who use special cold-weather gear (such as warm coats, gloves, facemasks, and studded shoes) to help them survive the extreme conditions.

However, there are species that live in the region, many of which are endemic—that is, the species can only be found in the Antarctic. Wildlife on the continent and in the surrounding ocean—such as fish, seabirds, and marine mammals—are well adapted to the Antarctic environment and thrive in its cold habitat. For example, Weddell seals, one of the six species of seals that live in the Antarctic, have low surface area to volume ratios (which reduces the amount of heat lost to the environment), a layer of blubber (fat which helps insulate and can be used as energy when food is unavailable), streamlined bodies (which conserve energy while swimming), and eyes that see very well in the dim underwater conditions.

With their distinctive waddle and black and white coloring, penguins are perhaps the best-known Antarctic animal. Penguins and seals share many characteristics that help them succeed in the climate, but there are also adaptations that are specific to penguins. For instance, penguins are covered in densely packed, overlapping feathers that easily shed water and protect against the wind. They also have an inner layer of downy feathers, which traps air and adds insulation. They have mechanisms for regulating temperature, such as standing with minimal body contact with the ice—they rock back on their heels and balance with their tail, which doesn't lose much heat to the ice because there is no blood flow in feathers. In addition, their circulatory systems adjust to conserve or release heat as needed. Penguins eat krill, fish, and squid and use their wings as flippers to swim gracefully in the water; and because they are flightless, their bones are denser than those of flying birds, allowing them to swim and dive to greater depths.

Other Antarctic seabirds have similar diets of krill, fish, and squid, but have very different characteristics. Albatrosses, for example, are adapted to fly and utilize the updrafts over the ocean. They have light, hollow bones and long, narrow wings with a "shoulder lock" that keeps the wing extended without straining the muscles. Albatrosses are so efficient at gliding that they can travel thousands of miles in a single foraging flight.

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