May 1, 2019
Although they have wings and feathers, penguins cannot fly. Instead, they have evolved into the most efficient swimmers and divers of all birds. Some species spend 75% of their time at sea — the most of any birds.
Penguin wings are stiff, short flippers to propel them underwater — they literally fly through the sea. Their legs are set far back in the body, and together with the tail form an underwater rudder to their perfectly streamlined bodies. Their cruising speed in water is about 10km per hour. To catch their breath and to save energy while swimming, they leap clear of the water every few metres.
They are excellent divers, descending to depths of over 250 metres, though most of their dives will be in the top 10 metres. Unlike flying birds, their bones are dense to make diving easier. Underwater they are every bit as fearsome to their prey as lions are to theirs!
However, penguins are rarely seen underwater, so our main impression of them is confined to how they appear on land. With their legs set far back for efficient
movement underwater, the penguins walk awkwardly in a very upright position. This is possibly the reason for their extraordinary appeal — they look like funny little people.
Even on land, penguins are surprisingly agile. They can travel vast distances on foot or by ‘tobogganing’, sliding on their bellies over the ice, propelled by their
wings and feet. Some penguins are able to hop up great heights compared to their size.