Did you know that all penguins practice fasting during the year? Prior to fasting, penguins build up a thick fat layer which will provide energy during the fast period. Penguins fast for two reasons. First, some species don't leave their nesting grounds during the entire courtship, breeding and incubation period. Their food is found in the water so they are unable to feed if they don't leave the nesting grounds. Penguins also fast during seasonal molt. When their new waterproof feathers are just growing in, they are unable to enter the water to feed. Different penguin species have different fast lengths. The male Emperor Penguin has the longest fasting period during breeding season. While preparing and caring for chicks, a male Emperor Penguin will fast for an incredible 90 to 120 days! If you can't get enough of this extreme avian species, be sure to check out all of Birdorable's cute penguin t-shirts & gifts.