Do all birds have gizzards?

The gizzard is very thick and muscular in some species, such as ducks, gallinaceous birds (those related to chickens such as grouse, quail, and turkeys), emus, and doves. Most of these birds eat hard items such as seeds and nuts. Birds with thick gizzards frequently pick up grit—little stones, sand, and small shells. read more

What we call a gizzard is the muscular part of a bird’s stomach. When a bird swallows food, it goes from the throat to the esophagus. Some species have an expanded, thin-walled offshoot or pouch in the esophagus called the crop where they can store food before it’s sent the rest of the way through the esophagus to the stomach. read more

In layman's terms, the gizzard 'chews' the food for the bird as it does not have teeth to chew food the way humans do. Bird gizzards are lined with a tough layer made of the carbohydrate-protein complex koilin, to protect the muscles in the gizzard. read more

All birds do have a gizzard, but those species that eat very easily digested foods such as soft-bodied insects, soft fruits, or nectar may have a very small and thin-walled gizzard. read more