The enzymes that act inside the small intestine are amylase, protease, and lipase. Amylase acts on starch and breaks it down into small carbohydrate molecules. Protease acts on proteins and breaks them down into amino acids. Lipase breaks down dietary fats into smaller molecules called fatty acids and glycerol.
Sandhill Cranes mate for life, choosing their partners based on dancing displays. Displaying birds stretch their wings, pump their heads, bow, and leap into the air. Although each female usually lays two eggs, only one nestling typically survives to fledge.
Do Bluebirds mate for life? The answer is probably maybe sometimes. Bluebirds do form pair-bonds during the breeding season. They are generally socially monogamous, meaning that a single male and female form a basic social unit in breeding territory.