Crop (anatomy)
In a bird's digestive system, the crop is an expanded, muscular pouch near the gullet or throat.  It is a part of the digestive tract, essentially an enlarged part of the oesophagus.  As with most other organisms that have a crop, the crop is used to temporarily store food.  Not all birds have a crop.  In adult doves and pigeons, the crop can produce crop milk to feed newly hatched birds.