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
Birds of the Danube Delta territory. As far as the habitats are concerned, the species of the aquatic ones almost exclusivity feed from the aquatic millennium, while those living in the terrestrial habitat hardly have 50 per cent terrestrial food, the remainder having a mixed and aquatic origin. Many species owe their presence or existence in the delta – in rather high densities as compared to the rest of the area – just to this food richness. The contrast created between the great food abundance available as compared to the existence for some species of plenty of sites for nest location resulted in the simple