Penguins
Penguins
Penguins are one of the oldest creatures on Earth having co-existed with the dinosaurs some 60 million years ago. Birds started in the southern hemisphere on the hypothetical continent of Gondwana which present theories said split into Australia, Antarctica, South America, Africa and India.
Penguins range from the Galapagos Islands near the equator to South America, South Africa, Australia, New Zealand and of course the Antarctic Islands and continent. There from 17 to 25 different types depending on what are classed as different species, for example some authorities consider that there are 4 distinct types of rockhoppers. Others have suggested that the more southerly adelies may be a sub-species. Many are specific to particular islands so have evolved to be different from related species. The Magellanic types, for example, which are variously called the jackass from their loud donkey-like bray, Magellanic or Humboldt penguins, occur in South and South West Africa (African penguin), South America from the Galapagos off Ecuador (Galapagos penguins) down to the tip of Chile and Cape Horn and on the Falklands and sub-Antarctic islands.
All penguins have black and white markings, white underneath which when they are in the sea helps delude predators since the white against the light sky above the sea makes them less obvious. Similarly the black backs against the darker depths of the sea camouflages them from the eyes from the eyes of predators above.
Penguins have an oil gland near the base of the tail and must preen to rub the oil all over their feathers to make them waterproof. If the feathers become wet the birds cannot swim and also become cold.
Penguins have a high internal body temperature (38degrees C or 101 degrees F) and a high metabolic rate. The sea they swim in can be as low as -40degrees C without freezing if there are no nuclei for ice crystals to form on.
Penguins are covered with tightly packed overlapping feathers. They also have a thick layer of blubber just below the skin, which is why they, like seals, were victims of the sealers boiling pots. On the lower parts of the feathers there are tufts, which form an insulating layer of fluffy down. They have around 70 feathers per square inch. Penguins, like other birds, lay eggs and both parents rear the chicks.
Penguin Teeth
Penguins do not have teeth as such but do have a matrix of white tooth-like spikes on the tongue and roof of the mouth. These face towards the back of the throat and so help the penguins to swallow a fish and stop it from wriggling back out. Lampreys’ mouths look a little bit similar. Like other sea birds they swallow fish head first.
Penguin ears
Penguins do not have external visible ears but do have an ear entrance under their feathers. They can hear both above and below the water.
Their diet can be sardines, krill, anchovies and squid.
Penguin modes of travel
Penguins have 6 main ways of travelling around. These are: waddling on land; hopping, as do the rock-hoppers; tobogganing on their tummies, common with the emperor penguins when moving through snow and ice when they push from the back with their feet and from the sides with their flippers; high speed “flying” underwater; porpoising by shooting in and out of the sea while speeding through the sea and by floating and swimming on the sea like ducks. When they walk they are classed as plantigrade, ie an animal that walks on the soles of its feet like a bear. ( from planta sole and gradus walking).
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