How Do Birds Chew Their Food?
Birds have a unique way of chewing their food. They must swallow their food whole because they have no teeth. In the place of teeth, there is a light bill for grasping food. The work of chewing is done by the gizzard, a muscular part of the bird’s stomach.
When the food that the bird has swallowed passes into the gizzard, the food is crushed by the strong grinding movements of the tough gizzard lining. Birds that eat seeds and other very hard food sometimes swallow gravel and small grit along with the food, to aid the gizzard’s grinding process.
If the food is particularly tough, it may move between the proventriculous and the gizzard several times for more efficient digestion. Once the food is sufficiently broken down, it moves into the small intestine, where the liver and pancreas help with absorbing nutrients.
Next is the large intestine, which is very short for most birds. Where the small and large intestines join are the ceca, two pouches that help absorb any remaining water from the food and finish the digestive process.
After digestion, any remaining material, both liquid and solid, food passes through the cloaca to be expelled from the bird’s body. For many birds, waste products can also be expelled from the gizzard in the form of pellets – fur, bones, tough husks and other materials that cannot pass through the bird’s intestines are compacted into a small ball of material and regurgitated through the bill.
The time it takes a bird to digest a meal depends on several factors, including the type of food and the bird species eating it. While the general digestive tract is the same for all birds, the size and shape of different organs, particularly the crop and gizzard, will also vary for different bird species.