IT MAY be ungainly, but a penguin鈥檚 waddling gait is actually quite
efficient. Researchers had thought that waddling from side to side wasted
energy鈥攚hen walking, penguins use twice as much energy as other animals of
a similar weight. So Timothy Griffin of the University of California at Berkeley
and Rodger Kram of the University of Colorado at Boulder measured the forces
exerted by five emperor penguins as they walked across a platform.
This showed that the penguins don鈥檛 waste the 鈥渟ideways energy鈥�, but instead
store it up as potential energy, just like a pendulum swinging (Nature,
vol 408, p 929). Griffin suspects that it鈥檚 the birds鈥� short legs that make
walking such hard work for them.