A Brief Communication in this week's issue of the journal reveals that a male king penguin (Aptenodytes patagonicus) can preserve food in his stomach for up to three weeks.
He can draw on this internal larder to feed his chicks - while fasting himself - should his mate be delayed on a foraging trip, said the researchers from the Centre National de la Recherche Scientifique, Strasbourg, France.
"This is presumably an adaptation to the large, but highly variable, marine resources of the austral ocean," suggest Yvon L. Maho and colleagues.
In a second Brief Communication, it has been revealed that a penguin's waddling actually conserves mechanical energy.
Timothy Griffin of the University of California, Berkeley, and Rodger Kram of the University of Colorado, Boulder used a ‘force platform' in their research- something "like a fancy bathroom scale that measures forces in the vertical, fore-aft, and sideways directions at each instant."
Instead, they found that it is the penguin's short legs that waste energy.
"Walking is energetically expensive for these odd-shaped birds because their short legs require them to generate muscular force rapidly," they concluded.