Further down in the digestive system is the gizzard, an organ which helps to grind down food into small chunks. Although a great deal of muscle is used to accomplish this objective, much of the fragmentation occurs as a result of small stones, or grit, that the bird has eaten. Birds must regularly ingest small amounts of pebbles or coarse sand to keep the gizzard working properly.
The lower part of the bird's two-part stomach. It grinds and softens foods. Seed-eating birds may eat grit or small stones to help with grinding. In birds that eat fish or other meat, the gizzard molds indigestible material, such as bones and feathers, into compact balls (pellets) that are then ejected through the mouth.
A specialised part of the digestive tract with well muscled walls that is used to help break down tough materials such as plants. Most birds have a gizzard which helps to grind up seeds for example. They often supplement the action of the gizzard by swallowing gravel; when the gizzard walls contract, the stones are ground against the seeds and crush them. Many of the large herbivorous dinosaurs are thought to have had gizzards too.
The highly muscular, second enlargement in a bird's digestive tract that, together with the first enlargement, functions like the human stomach. If you dissect the dried, mummified remains of any nestling martin you find in the nests at season's end, you will invariably find the black, grape-sized gizzard completely impacted with broken glass, metal fragments, shells, and white quartz pebbles that the parents characteristically feed their nestlings for grit.
The gizzard (also called the gastric mill) is the part of the stomach that grinds up food (usually tough plant material), often aided by gizzard rocks. Many birds have a gizzard, as did some dinosaurs.
The gizzard grinds food one more time before it enters the stomach. Other animals (including birds and some dinosaurs) have been known to swallow stones to grind things up in their gizzards. But cockroaches have another set of little teeth in there to do the job (those would be tough teeth for a dentist to examine, huh?).
A gizzard is a specialized stomach with a thick, muscular wall used for grinding up food. It is found in birds, reptiles, earthworms, some fish, insects, mollusks, and other creatures. In certain insects and mollusks, the gizzard features chitinous plates or teeth.