Question

Why do birds possess hollow bones answer in simple words?

Answer 1

hollow bones make birds bodies lighter.
In some bones, the hollow cavities contain extensions of the air sacs from the lungs. These air sacs help the bird to get the oxygen it needs to fly quickly and easily.

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Answer 2

Birds possess hollow bones to make their weight light so that they can fly easily without wasting so much energy in flipping their wings.

Explanation:

All the birds have bones just like every creature with bones. Their structure is same from outside. It is hard and rigid but unlike human bones which are filled with bone marrow, the bird’s bones have an air cavity.

Some bones have air sacs which are attached to the bird’s lungs and provide more area to store more oxygen and help the bird to fly quickly.