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 to mimic speech. Among reasons for their popularity is that they can be kept in homes too small or otherwise unsuitable for dogs or cats. The cagebird trade in some parts of the world threatens certain species with extinction, when birds are illegally captured in the wild. For example, in Indonesia, at least 13 species are close to extinction including the Indonesian national bird, the Javan hawk-eagle, while five subspecies including the scarlet-breasted lorikeet may have become extinct in the wild. Pet birds are kept in their millions, as are domestic fowls, bantams, and pigeons. These last had an important