Just like humans, animals have to budget their precious resources and the most important resource to an animal, especially those that live in very cold environments, is energy. Penguins need to save every scrap of energy possible to survive the freezing Antarctic temperatures, especially when fasting during the winter breeding season.
Male king penguins can go more than 50 days without food when they are incubating an egg, and during this time saving energy is crucial. Even when their energy is most precious, king penguins devote more than 20 per-cent of their time to what researchers have termed ‘comfort behaviour’.
This behaviour ranges from elaborate preening to a simple yawn, but every tiny movement requires energy. Preening raises the heart rate of a king penguin from a resting rate of 60 beats per minute to over 110 beats per minute, and it takes three minutes for the heart to return to its resting rate.
Clearly these comfort behaviours are important and without preening the penguin’s feathers may become subject to parasites. If their feathery insulation layer becomes damaged they would expend much more energy through heat loss, so king penguins use their energy wisely to survive.
Image from www.flickr.com/photos/liamq