[Reducing of the energy expenditure during fasting in the royal penguin (Aptenodytes patagonicus)].

In isolated King Penguins there is a 80% decrease in the daily change in body mass; at the same time the resting metabolic rate decreases by 55%. The decrease in change in body mass and metabolic rate occurs mainly during the 5 first days of fasting (decrease of 65% in the daily change in bodymass and 35% in resting metabolic rate). This result is attributed to a quick transition to an economical level of energy expenditure.