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P…P…P…Pick up a Penguin
- a well-known advertising slogan
Penguins are birds that don't fly but are just as happy as fish in water. They belong to the order of Sphenisciformes and family Spheniscidae, which have been around since the Eocene era (40 million years ago). There are a total of 17-18 species of penguin and an estimated 100 million penguins in the wild, with the largest being the Emperor Penguin (Aptenodytes forsteri) and the smallest penguin being the Little Blue Penguin (otherwise known as the Fairy Penguin). Generally speaking, the penguin can be found to be anything from 40 cm to 1.1m tall (16" to 3'7") and weigh between 1kg (2.2 lb) and 35kg (75 lb).
It is thought that the colder the climate, the bigger the penguin that lives there, for larger birds retain more heat. Thus the bigger penguins such as the Emperor penguin can be found occupying places like Antarctica. Smaller penguins which don't retain much heat live in warmer places such as the Galapagos Islands, New Zealand, southern Australia, South Africa and along the coast of South America.
Penguins have also adapted to overheating in warmer regions by having no feathers on their feet, changing their blood flow around their bodies, changing their stance, lifting up their feathers and having bare skin on parts of their face.
It is a well known fact that penguins are black and white1. But why are they? The answer is simply for camouflage. When a predator of the penguin such as an orca or leopard seal sees a penguin in the water it cannot distinguish the penguin's white tummy from the reflective water surface.
Not only are penguins well adapted to life in the southern hemisphere regarding camouflage, but they are also well adapted to life there through their plumage2. Penguins also coat their feathers in oil from a gland near their tail to increase impermeability to water.
Penguins have blubber to keep them warm. This also makes them buoyant, but so buoyant that it makes it difficult for them to swim under water, so penguins have evolved heavy bones to cancel out the effect of the blubber and to allow them to swim underwater. In the water penguins can reach speeds up to 15-17mph which is four times faster than the fastest recorded human swimmer. To aid them in swimming, penguins have torpedo-shaped bodies and firm flippers which make them streamlined. Their webbed feet and stubby tails enable them to steer their way through the water and even do jumps.
They also reach great speeds on land too having employed a technique called tobogganing, which enables them to conserve energy. To keep upright penguins rely on their (flightless) wings and tails.
They have a good sense of hearing and their eyes are adapted for underwater vision and are their primary means of locating prey and avoiding predators; in air, conversely, they are short-sighted. Penguins also possess little or no sense of smell and taste. Their mouth is like that of a venus fly trap plant for their tongue and palate are covered with stiff spines that constitute a one-way trap. These spines help grip slippery food and help the penguin consume it. When eating their food in water, penguins take in sea water. To help them deal with the salt content penguins possess glands near their eyes which filter out the salt from their blood stream.
What's on the Menu?
Foraging takes place all year round, but sometimes it will take longer than others to find food. Emperor penguins have been known to spend up to 60 to 70 days foraging for food at sea, compared to Gentoo Penguins that spend as little as 4 to 12 hours finding food during the breeding season.
Penguins usually lunch on krill, fish and squid. But if these are unavailable, they will try to catch other sealife forms to eat. A penguin's meal can weigh up to 30 pounds, which they are happy to consume once they have hunted it down using their high speeds and agility.
Penguins are very sociable creatures and appear to have no real fear of humans. They live and breed in large colonies (called rookeries) and even hunt and swim in groups. Depending on the temperature of the water, numbers of penguins foraging for food together will differ. For example, if the water is warmer then there will be less penguins looking for food together because in cold water schools of fish tend to be larger.
Penguins communicate with one another by flipper waving, calling, bowing, gesturing and preening. Aggressive postures like stares, pointing, and charging can be displayed in disputes over territory. Sometimes during courtship, the male pumps his chest several times and, with his head stretched upwards and flippers akimbo, emits a harsh loud braying sound. This can cause the other males to trumpet in chorus.
Penguins also display strange characteristics when it comes to socialising such as stealing another mother's chick by a mother who has lost their chick to a storm or something similar. Male penguins have been known to partner up with other male penguins and instead of putting an egg in the nest will put a pebble in it.
Like many other birds penguins migrate during the seasons even though they cannot fly.
As for the belief that aircraft make penguins topple over, this is just a myth.
Reproduction and Offspring
When it comes to reproduction some penguins will mate for life, others just for the season. Most species of penguin lay two eggs but larger penguins such as the Emperor and King Penguins lay only one. Penguins also differ in that some will create nests3 to protect their eggs. Others like the Emperor penguin won't build nests but carry their eggs around on their feet and protect them with a flap of skin (brood patch) that enables the eggs to keep warm even if the temperature drops to 80 degrees below zero (Fahrenheit). The male Emperor penguin is also the only penguin to incubate the eggs while the female does the caring and crêching. It can take about eight weeks for them to hatch. Larger penguins lay larger eggs which take longer. After a while baby penguins are left to fend for themselves in crèches, allowing their parents to be able to forage together for food. As the chicks grow larger they grow a thick coat of downy feathers that allows them to keep warm and dry by themselves. Penguins can live as long as 25 years.
Although penguins are protected by law, this doesn't mean that they aren't under threat. In fact it could be thought that the unseen threats surrounding penguins are more detrimental than those that are seen (like picking up a penguin's eggs and having them for tea).
An example of an invisible threat is that the oceans in the southern hemisphere are polluted. Of course the oceans do not instantly kill off the penguins and their fellow sea friends, but they do still pollute them and contribute to their eventual death4.
This silent but deadly threat to sealife is sadly caused by humans in their attempt to get rid of their waste. Plastic bags, fish nets, glass, bottles and cardboard all can be found floating around the sea if not scattered on the coasts. Not content in polluting these animals humans also consume fish stock that would otherwise cause a penguin to have a bite to eat.
Global warming, pollution and tourism have all affected the penguin population around the world. Leaving the penguins with little to feed on, breaking up their habitats and leaving them open to disease. In the Antarctic two giant icebergs broke up a colony of penguins, and left the parents with the difficulty of feeding their chicks as they have to walk up to 50 kilometres (30 miles) further than usual to get food.
Finally, penguins although not preyed on by humans, face being preyed on by other animals such as the skua (catharacta), killer whales, leopard seals (Hydrurga leptonyx), Fur Seals (Arctocephalus Spp.), Sea Lions (Otaria bryonia) and Elephant Seals (Mirounga leonina).
Flippers About Film
Penguins have also appeared in films and cartoons. For instance, Batman, Madagascar, Mary Poppins, Pingu, Wallace and Gromit and The March of the Penguins to name but a few. Furthermore, they have made an appearance in the world of book publishing and on chocolate bars and adverts.