{"fact":"Crows don't have a crop, a food storage pouch that pigeons have. So crows eat less in one sitting but need more frequent meals.","context":"The most obvious basis for this difference is that pigeons have a crop, while crows do not...Adjustments in food presentation time, session duration, or both must be made to aviod satiation effects.","source":"Robert W. Powell, Operant responding in the common crow (Corvus brachyrhynchos), 10.3758/bf03334384","index":683}