Physical adaptations
Thick, windproof or waterproof coats
Many Antarctic animals have a windproof or waterproof coat.
Emperor penguins are a very good example. These birds have 4 layers of scale-like feathers. The layers overlap each other to form a good protection from the wind, even in blizzard conditions.
Fat (or blubber) layers
Whales, seals and some penguins have thick layers of fat (or blubber). These fat layers act like insulation, trapping body heat in. The effect is like wrapping yourself in a blanket.
When blood circulates close to the skin, precious body heat is lost. Some animals can selectively reduce the flow of blood to their blubber layers. This reduces the amount of energy it takes to stay warm by keeping blood further away from the skin surface.
Blubber layers can also be used as an energy reserve. Male elephant seals can live off their fat reserves during summer.
Small extremities
An extremity is a limb or appendage of the body. In humans, our hands and feet count as extremities. These are often the first places to feel the cold. The same applies for animals.
Emperor penguins have small extremities. They have a very small bill and flippers, which means less blood is required for these areas. Keeping blood flow away from the skin surface means that less body heat is lost.
Specialised adaptations
Emperor penguins have special nasal chambers which recover heat lost through breathing. They also have closely aligned veins and arteries. These adaptions enable emperor penguins to recycle their own body heat.
Antarctic krill must survive the dark winter months when food is scarce. They do this very successfully, surviving more than 200 days of starvation. They do this by shrinking their body size. ‘Downsizing’ enables Antarctic krill to use their own body proteins as a source of fuel. All species of krill seem to share this adaptation.
Behavioural adaptations
Antarctic animals have unique behavioural adaptations that help them survive the harsh winter.
Emperor penguins form large huddles. Huddles allow them to share body warmth, and shelters many of the penguins from the wind. The huddle constantly moves so that all the penguins have a turn in the middle. Huddling can reduce heat loss by up to 50%.
