Crop (anatomy) Crop (anatomy) A crop (sometimes also called a croup or a craw, or ingluvies) is a thin-walled expanded portion of the alimentary tract used for the storage of food prior to digestion. This anatomical structure is found in a wide variety of animals. It has been found in birds, and in invertebrate animals including gastropods (snails and slugs), earthworms, leeches, and insects. Cropping is used by bees to temporarily store nectar of flowers. When bees "suck" nectar, it is stored in their crops. In a bird's digestive system, the crop is an expanded, muscular pouch near the gullet or throat.
Human uses of birds whereas an antelope can yield as much as 31,000 kcal/hour, and wild rye around 1,000 kcal/hour. Birds have been domesticated and bred as poultry for use as food for at least four thousand years. The most important species is the chicken. It appears to have been domesticated by 5000 BC in northeastern China, likely for cockfighting, and only later used for food. In ancient Egypt, poultry including ducks, geese, and pigeons were captured in nets and then bred in captivity. Chicken now provides some 20% of the animal protein eaten by the world's human population in the form of meat