They use their wings very much as sea lions use their flippers. Penguins can swim very fast, turning as sharply as the fish they are chasing. The largest specimens can go up to18 kph under water. On land, they waddle clumsily and seem ready to collapse with each step.

Aside from the comic appearance of their gait that has inspired many a cartoon character, this mode of locomotion is physically exhausting for them.

That’s why some penguins adopt the more efficient technique of sliding on the ice by propelling themselves on their bellies in polar regions.