Birds have a gizzard

The idea

Birds have no teeth but have a chamber called the gizzard, whose walls contract and relax to break down food, often helped by swallowed grit (small stones).

No teeth

A hen eats whole grains, but it has no teeth.

How does a bird break up its food?

• With a chamber called the gizzard
• With its feathers
• It does not break it up

Squeeze

Turn Grit on. Then press Squeeze three times. Watch the grains.

Walls and grit

The walls of the gizzard contract and relax and break the grains. The small stones, called grit, help. (The numbers of pieces in the drawing are an example.)

Birds have no teeth but have a chamber called the gizzard. Food is broken down by the contraction and relaxation of the walls of the gizzard, often with the help of grit (small stones) that the birds swallow.

Notes

Birds have no teeth but have a chamber called the gizzard. Food is broken down by the contraction and relaxation of the walls of the gizzard, often with the help of grit (small stones) that the birds swallow.

Check yourself

What do birds have instead of teeth to break their food?

How does the gizzard break food?

What is grit?

Why do birds swallow grit?

• A tongue with teeth. Birds do not have teeth. They have a chamber called the gizzard.
• A gizzard — correct. Yes!
• A pair of lungs. Lungs are for breathing. Birds break food in the gizzard.
• It heats the food. The gizzard does not heat the food. Its walls contract and relax.
• It dissolves the food in water. The gizzard breaks food by the contraction and relaxation of its walls.
• Its walls contract and relax — correct. Yes!
• Small stones that a bird swallows — correct. Yes!
• A kind of grain. Grit is small stones, not grain.
• A juice made by the liver. Bile is the juice made by the liver. Grit is small stones that a bird swallows.
• It keeps the bird warm. Grit does not warm the bird. It often helps the gizzard break the food.
• It often helps the gizzard break the food — correct. Yes!
• It gives the bird its colour. Grit does not give colour. It often helps the gizzard break the food.