Today's science lesson: because birds are small and have a high need for energy they can digest food rapidly. This is one reason young birds mature quickly and migrating birds are able to store fat which enables long flights. There are species of birds that are known to increase their weight 40% in 10 days.
Birds may break up their food or crush it with their bill, they don't chew it. Parrots, birds of prey, and finches have short, thick, fleshy tongues which allow them to manipulate their food. Where humans swallow with our soft palates, birds have to tilt their heads back to get the food from inside their mouth (buccal cavity) to the first part of their throat (Oesophagus). The oesophagus continues to draw the bird's food down into it's body - where it stands at the Crop.
Parrots use the crop to store food eaten in a hurry so they don't get caught by preditors. From the crop food goes into the stomach where it finally begins to get digested. The stomach has two sections one of which produces the necessary digestive juices and enzymes which soak the food which is then passed to the gizzard. The gizzard has a lot of muscles that grind up the food - what we do with our teeth.
Digested food now moves to the first part of the small intestine which is divided into two parts and where most of the digestion and absorption of the food now occurs in the parrot's gut. A bird's pancreas is actually better developed than a mammal's pancreas. This is probably to compensate for a lack of some saliva and chewing. It produces proteins, digesting enzymes, carbohydrates and fat which are delivered into the small intestine.