So, what does it take to survive in Antarctica? Cold Feet! Extremities such as "feet" and "hands" do much of the important work of moving about in Antarctica. Here where resources such as food and nesting territories are far apart wildlife has to have efficient and proven methods of getting from here to there. We can compare the postition of these extremities to our own, but the similarities stop there!
Top left: chinstrap penguin tracks in snow. Three large toes connected by webbing and each topped off by a well-developed claw make a penguin track. The claws are essential for gripping ice and snow; the webbing acts as a snowshoe and for paddling in water; the bones of the foot are fused into one for extra strength. Some penguins walk a hundred miles between nesting sites and open water to feed, where they use their wings, not their feet, to move about. Limited bare rock for nesting means some penguins must climb high up snow covered hills to reach windblown rock outcrops at the beginning of the nesting season. Short austral summers don't allow them to wait for the snow to melt and expose sites closer to water.
Top right: Weddell seals are true seals, meaning they have limited ability to move about on land. For one, their front flippers are very short and cannot support their weight. But they are excellent foils for steering when in water and claws located at the tips of the digits (they have five fingers as do you and I) help them haul out on snow and ice.
Bottom left: the hind flippers of the Weddell seal are the propeller that makes them go in the water. Here you see them in their relaxed position. The five digits are connected by highly elastic webbing that stretches to increase the surface area many times over what you see here, with each swoosh from side to side.
Bottom right: webbed feet are a common adaptation among marine birds. This design is perhaps the most common: three more or less even-length toes, wide spread and connected by webbing. Claw marks are present but not nearly as prominent as in penguins. After all, birds with these feet can fly and so their relationship with the ground (snow and ice) need not be as secure. These are tracks of a southern giant petrel. Similar in shape to tracks of gulls, skuas and ducks, the size is the identifying feature. they are huge. Almost 8 inches across! Southern giant petrels are known as the vultures of the Antarctic and often scavenge carcasses on land, hence the need to walk around -- something their relatives the albatrosses have a difficult time doing.
Center: penguin wings are modified to perform as wings underwater. For this they are strong and narrow and coated with a layer of waterproof feathers. Penguins often get about on snow by tobogganing, using their wings and feet for propulsion as they slide along on their bellies.
All in all, without the proper extremities life in Antarctica would be very difficult indeed!
