Description

Early Antarctic explorers actuallythoughtpenguins were fish and classified them accordingly. In fact,asbirds, they are superbly designed for their job, flyingunderwaterwith great skill. Their compact bodies have a breastbonethat makesan excellent keel and they have massive paddle muscles topropelthem at speeds up to 25 miles per hour.

Waddling and energy savings - If you've ever seen apenguinwalking, you'll have seen it moves along with rather acomicalmotion swaying from side to side with each step like anupside downpendulum. This is a consequence of being a talltop-heavy animalwith short legs. Recently studies have found thatthis is actuallya very efficient way of walking with the swayingmotion leading toan 80% energy saving compared to a more staticwalk. They can movequicker and more efficiently out of the water by"tobogganing" onslippery icy or snowy surfaces, they lie down ontheir front andpush themselves with their feet, using strong toesand claws to geta grip, in this way they can outpace a runninghuman. Unlikely asthey look, penguins ways of moving themselves onland are effectiveenough to cover 100km or more at times if coldweather freezes thesea between the open water and their nestsite.

Penguins can come out of the sea onto rocky shores orslipperyice during rough weather - strong claws that can grip ontoslippery surfaces efficiently make this look far easier thanitis.

Smaller penguins "bounce" - Small size means less kineticenergyif the penguins are thrown around and so less damage. Thesmallerpenguin species can come out of crashing waves and roughseas oninhospitable, difficult rocky shores without being smashedtopieces precisely because they are small and so don't have somuchkinetic energy if bashed against a rock, an inherent toughnessandblubber padding helps too.

Feet pulled in when swimming - like an aircraft pulling initslanding gear to reduce air resistance, penguins pull theirfeetclose to their bodies when swimming for maximum streamlininganddrag reduction. However when needed they can be used likeawater-brake, stuck out at the right moment, a penguin can useitsfeet to make a 180° turn in 1/5th of a second.

Elbow and wrist joints are fused - this gives a morerigidforelimb that is developed into a paddle (flipper) forswimmingunderwater.

Collect air in their feathers by preening - like manyotherbirds, penguins spend a lot of their time preening theirfeathers,much of this is to fluff the feathers out and so collectairamongst them, this is done particularly before going to sea.Thereare two benefits, firstly it aids insulation and secondly whenthepenguin swims particularly quickly this air is releasedasmicro-bubbles which lubricates the penguins path through thewater,so reducing drag. It has been shown that penguins can leavethewater in a burst of speed in this manner that is twicetheirtheoretical swimming speed without it. Particularly useful ifbeingpursued by a predator or if a jump to extra height is neededto getonto the ice and out of the water.

Nest building - All but king and emperor penguins build anest,though they are usually only a simple pile of stones thatarecontinually stolen and swapped between the members of a colonywhenthe owners aren't looking. The nests are slightly higher thanthesurrounding land so that if the temperature rises and thesnowmelts, the nest is not flooded. Emperor and King penguins keeptheegg and then the young chick on their feet covered by a broodpouchuntil they are large enough to regulate their owntemperature.