The crop (also the croup, the craw, the ingluvies, and the sublingual pouch) is a thin-walled, expanded portion of the alimentary tract, which is used for the storage of food before digestion.
[6] In a bird's digestive system, the crop is an expanded, muscular pouch near the gullet or throat.
In adult doves and pigeons, it can produce crop milk to feed newly hatched birds.
[7] Scavenging birds, such as vultures, will gorge themselves when prey is abundant, causing their crop to bulge.
[11] In the Sherlock Holmes story "The Adventure of the Blue Carbuncle" (1892), a valuable gem is hidden inside a bird's crop.