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 Human uses of birds Human uses of birds have included both economic uses such as food and symbolic uses such as art, music and religion, for thousands of years. In terms of economic uses, birds have been hunted for food since Palaeolithic times. They have been captured and bred as poultry to provide meat and eggs since at least the time of ancient Egypt. Some species have been used, too, to help locate or to catch food, as with cormorant fishing and the use of honeyguides. Feathers have long been used for bedding, as well as for quill pens and