Digestion a thin-walled expanded portion of the alimentary tract used for the storage of food prior to digestion. In some birds it is an expanded, muscular pouch near the gullet or throat. In adult doves and pigeons, the crop can produce crop milk to feed newly hatched birds. Certain insects may have a crop or enlarged esophagus. Herbivores have evolved cecums (or an abomasum in the case of ruminants). Ruminants have a fore-stomach with four chambers. These are the rumen, reticulum, omasum, and abomasum. In the first two chambers, the rumen and the reticulum, the food is mixed with saliva and
Human uses of birds death, being sacred, or being used in heraldry. In terms of entertainment, raptors have been used in falconry, while cagebirds have been kept for their song. Other birds have been raised for the traditional sports of cockfighting and pigeon racing. Birdwatching, too, has grown to become a major leisure activity. Birds feature in a wide variety of art forms, including in painting, sculpture, poetry and prose, film and fashion. Birds also appear in music as well as traditional dance and ballet. In certain cases, such as the bird-and-flower painting of China, birds are central to an artistic genre. Culture consists