Penguins are found in the desert Antarctic and have special adaptations to suit their frigid climate. These birds cannot fly, but yet have wings, and unlike normal birds, spend a fair amount of time in the water.
There are 17 identified penguin species in the world, and out of them, seven can be considered as Antarctic penguins. These are the Adélie penguin, the Chinstrap penguin, the Emperor penguin, the Gentoo penguin, the King penguin, the Macaroni penguin, and the Rockhopper penguin.
Although penguins are mostly water borne, they lay their eggs and raise their chicks on land. They are heavy animals with blubber fat insulating them, similar to that of the polar bear, and feed mostly on krill, squid, crustaceans, and other forms of sea-life.
The Adélie penguin and the Emperor penguin are probably the most common and classic penguin species found on the Antarctic desert.
The Adélie penguins breed in the far south of the pole but head north at the onset of winter. These birds are small and compact, which allows them less fat loss because of the low surface area to volume ration.
Their feathers are thick and layered with fat. The thickness provides them with insulation when on land, while the layer of fat keeps them from freezing under the icy waters. Their wings are also very short, serving the purpose of flippers for underwater swimming rather than for flying (which penguins cannot do)!
They have an amazing anatomical adaptation in their mouths that prevent the slippery sea prey from escaping. That is backward pointing barbs on their tongues.
Their markings too are very distinct; black on the outside and white on the underneath. This adaptation is to make them less visible when they are in the water, while allowing them to warm up or cool down on land (they turn their backs to the sun when they want to warm up and their stomachs to the sun when they want to cool down).
The Adélie penguins also have certain behavioral adaptations that allow them to live in the Antarctic desert. Besides migrating north at the end of summer, these birds save their energy on long journeys by ‘tobagganing’ (sliding on their fronts while pushing with their legs).
They also know how to build nests with stones and rock for the eggs during nesting season. These stony nests prevent the eggs from freezing up during the summers melting snow.
They also believe in strength in numbers. These penguins dive into the waters in groups, and gather at the edge of the ice before doing so.
When they dive into the deep waters, their heat rates slow down from a staggering 80 to 100 beats a minute to a mere 20 beats a minute. They also have an amazing kidney system that filters out the salt in the water, allowing them to gain water when they drink salt water.
The Emperor penguins are the biggest of penguins, and are twice the size of King Penguins. This size gives them a distinct advantage of being able to handle extremely cold temperatures.
These penguins have very short stiff tails that give them balance on land. It is like a tripod with heals and therefore does not have contact with the icy surface that would potentially lead to heat loss.
Their skeleton is very specialized that gives them tremendous advantage in their natural habitat. They have a tall upright way of walking with short legs and a short neck.
Their claws are very powerful giving them a great grip on ice, and rock and even when they are tobogganing.
The Emperor penguins also have a few behavioral adaptations that are unique to their special kind. They are not strictly territorial animals like other penguins, and so they huddle together in the winter to conserve heat that protects all of them.
They also breed during the height of winter. This means that when the summer rolls in and there is plenty of food to go around, the chicks are big enough and independent enough to find food on their own.
Unlike most penguins, the Emperor penguins do not build nests with stones. They keep the eggs on their feet, and once the eggs hatch, the chicks too sit on the parents’ feet and are protected by the folds of skin to keep them warm.
The male nurses the egg for about a period of 115 days. Once the female has laid the egg, she gives it to her partner who guards the egg while she goes out to sea for about 115 days to look for food.
The males have a mechanism that allows them to produce milk in their throats (esophagus) so that they can feed their chicks in the winter, if the female has not go back from fishing.
These penguins have an innovative heat exchange system that allows about 80% of the heat in their breath to be recaptured through their nose.
They also have a huge advantage over other penguin species when diving underwater. They can hold their breath up to about 22 minutes, allowing them enough time to reach depths in the ocean to catch sea life that other penguins are not evolutionally capable of doing.
Their heartbeat goes through dramatic changes too, especially when the animal is preparing to dive. When he is resting his heartbeats about 60 to 70 beats a minute, but rises to about 180 to 200 just before a dive. This rise is because they take in as much oxygen as possible. When they hit the water, the rate drops to about 100 bpm, and for the rest of his underwater journey, steadies at about 20 bpm.
Penguin chicks, irrespective of the specific species have adapted a mechanism that allows them to give each other mutual support after leaving their nest (or parent’s feet). They all form little crèches that gives them protection against predators.