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
The Clements Checklist of Birds of the World is the official list used by the American Birding Association for birds globally. eBird also uses the "Clements" checklist as the base list for its eBird taxonomy, which in addition to species includes hybrids and other non-species entities reported by birders. The Clements Checklist of Birds of the World The Clements Checklist of Birds of the World is a book by Jim Clements which presents a list of the bird species of the world. The most recent printed version is the sixth edition (2007), which was published by Cornell University Press. Previous editions were published by the author's own imprint,