How do birds fly?

Since I have always wondered "How do birds fly?" I decided to do some research and this is what I found out:

• Birds have hollow bones that are very light and strong.

• Their feathers are light and the shape of their wings is perfect for catching the air.

• Their lungs are great at getting oxygen and they are very efficient for flying over very long distances without getting tired.

• They eat lots of high-energy food.

• When a bird is flying, their wings are flat so that the air flows easily around it in the direction the bird flies (like your hand cutting through the water or air). However as the air flows over the wing, the air flows faster over the top than the bottom because the wing is slightly curved on top. This means there will be more air on the bottom side, because the air is moving more slowly. When there is more air on the bottom that leads to a push and since the push happens against that wide flat part of the wing, this push lifts the bird. So that means a bird's wing slices in the air in the forward direction and gets pushed up from below the result is a flying bird!

Here is a diagram of a birds wing.