Penguins are popular around the world, primarily for their unusually upright, waddling gait and, compared to other birds, lack of fear of humans. Antarctic penguins have a striking black and white coat. The distinctive colours and features of each penguin species are on their heads and neck — some are black and white, some have yellow patches, and others have elaborate coloured eyebrows.
Their striking black-and-white plumage is often likened to a white tie suit.
There are 17 species of penguins worldwide, none based at the North Pole. Four of the species live and nest on and around the Antarctic continent and another three live and nest on Antarctic and sub-Antarctic islands. So, in all, there are seven species that can be considered as “Antarctic Penguins.”
All 17 penguin species live exclusively in the Southern Hemisphere apart from the Galapagos penguin which just about qualifies as living in the Northern Hemisphere as it spans a narrow band at the equator in the Galapagos Islands.
Penguins are categorized into three families: brush-tail, crested, and King/Emperor penguins. Often referred as “flippered flyers” due to their effortless movement through the water and their possible evolution from gull-like birds. All penguins have similar body form and structure, but they vary greatly in size, from the little penguin weighing 1.1 kg and about 40 cm tall, to the Emperor penguin, which could weigh upto 40 kg and about 115 cm tall.
Emperor penguins are the largest of all penguins, an average 1.15 metres tall and 30 kg in weight. Emperors also are the most colourfully outfitted species.
Adélie penguins, named after the wife of the English explorer Dumont d’Urville, are small, on an average 70 cm high and weighing 5 kg.
Chinstrap penguins get their name from the thin line which circles from behind one eye under the chin to behind the other eye, much like a strap on a helmet. They are the about 68 cm in height and weigh 4.5-5 kg.
Gentoo, meaning “turban” refers to the whitish markings behind the eyes of this species. Gentoos range in size from 68 cm and 5.5 kg in the southern region to 71 cm and 6.2 kilos in the north.
Macaroni penguins got their name from their ornate yellow plumage above each eye. They were named after flamboyant dressers in the 18th century who were called “Macaroni Dandies.” They are similar in size and stature to the Adélies and Chinstrap penguins.
Rockhopper penguins are the smallest penguins in the Antarctica, measuring only 55 cm and weigh 2.5 kg. Similar to the Macaronis, Rockhoppers have a feathered crest on top of their heads.
Although they have wings and feathers, penguins cannot fly. Instead, they have evolved into the most efficient swimmers and divers of all birds. Feathers become worn out and must be replaced every year. During the 3 to 4 weeks of moulting, penguins come ashore. Because they are no longer waterproof when they lose their feathers and cannot go to sea to feed, penguins fatten up before moulting, gaining an astonishing 50–70% in weight.
Penguins walk with a comical motion, swaying from side to side with each step. This is a result of being a tall top-heavy animal with short legs. Studies show this is a very efficient way of walking with the swaying motion leading to an 80% energy saving compared to a more static walk.
They can move quicker, even faster than a running human, and more efficiently out of the water by “tobogganing” on slippery icy or snowy surfaces. Tobogganing is when they lie down on their front and push themselves with their feet, using strong toes and claws to get a grip. On land, they are capable of covering 100 km or more at times if cold weather freezes the sea between the open water and their nest site. Penguins can come out of the sea onto rocky shores or slippery ice during rough weather as their strong claws can grip on to slippery surfaces effectively.
Smaller penguins “bounce,” the small size means less kinetic energy if the penguins are thrown around and so they suffer less damage. Smaller penguin species can come out of crashing waves and rough seas on inhospitable, difficult rocky shores without being smashed to pieces as they are small and so don’t have so much kinetic energy if thrown against a rock.
Feet pulled in when swimming, like an aircraft pulling in its landing gear to reduce air resistance, penguins pull their feet close to their bodies when swimming for maximum streamlining and drag reduction. However, when needed, they can be used like a water-brake, stuck out at the right time. A penguin can use its feet to make a 180° turn in 1/5th of a second.
Penguins are well known for their swimming abilities. Using their flippers for propulsion and their feet as a rudder, penguins can swim in excess of 20 kmph. Through the use of air sacs to protect their lungs, penguins can stay underwater for 15 to 20 minutes and dive as deep as 900 metres).
In the water, penguins typically feed on krill and fish. The dietary habits of penguins are relatively easy to monitor. Krill eating penguins excrete pink quano, while those eating fish leave behind white guano. The yolks of penguin eggs often are red denoting the consumption of krill.
Although very near-sighted on land, they have exceptional vision in the water. Their eyes, like many sea animals, are attuned to the colours of the sea–green, blue-green, and violet. They need this excellent vision to avoid leopard seals and killer whales, which are their primary predators in the ocean. On land, their arch-enemy are skuas (large birds) which snatch penguin chicks from nests.
Like most other birds, penguins spend a lot of their time preening their feathers, done to fluff the feathers out and so collect air amongst them. This is mostly done before going to sea. First, it aids insulation and secondly, when the penguin swims quickly, this air is released as micro-bubbles which lubricate their path through the water. Penguins can quickly get out of the water if being pursued by a predator or jump to extra height if they need to get onto the ice from the water.
All but the King and Emperor penguins build a nest, usually a pile of stones that are stolen and swapped between the members of a colony when the owners aren’t looking. The nests are slightly higher than the surrounding land so that the nest is not flooded if the temperature rises and the snow melts. Emperor and King penguins keep the egg and then the young chick on their feet covered by a brood pouch until they are large enough to regulate their own temperature.
Immediately after laying her eggs, usually 1 or 2 eggs, the female heads for the open sea to replenish her food storage. The male incubates the eggs for the first 10-15 days while the female is away. Upon her return, the male spends 10-15 days at sea to fatten up. The male eventually returns to take the final shift of 3-7 days. During the courtship and incubation period, mates lose up to 45% of their initial body weight.
Chicks stay with their parents for about 3 weeks during which they grow rapidly. If food is short, it will be fed to the biggest and strongest chick only. After that, they join the other chicks in nurseries called créches. At that time, both parents go to sea to feed. This is the most dangerous time for a chick as skuas circling above continuously raid the nursery for fattened chicks. After 4 weeks of age, the chicks head for the sea when they are large enough to keep their own temperature constant.
Penguin colonies are very loud, raucous, busy and smelly. The call of all penguins is as unmusical and harsh as the braying of an ass. The colony is usually covered with penguin droppings. Colonies could be home to just a handful of breeding pairs or up to half a million birds and more. In the pure Antarctic air, one can smell a penguin colony, called rookery, from a long way away. The good news is that penguins are sociable creatures both on land and at sea.