Heather Lambie, age 10, of Victoria, B.C.,
How does a bird manage to fly?
The eagle soars in lazy circles and the feathery owl swoops down in silence. The sea gull glides with graceful ease and the partridge takes off with a whir of wings. Each type of bird seems to have a way of flying ‑ and each is a wonder to watch. Mankind watched and wondered, studied and envied the flight of the birds long ages before he dared to take his own flying machine off the ground. Now he can fly higher and faster than any bird.
The principles of flight are the same, whether a bird soars lazily on high or flutters with great to‑do from twig to twig. A bird uses his wings to push the air this way and that, He piles it into little cushions to lift himself aloft and pierces it to let himself through. To us the air seems a filmy nothing. To the bird, this‑filmy stuff can be used to keep him above the ground.
The body of a bird is light and streamlined. But the little pilot still has to learn how to fly and there is more to this than just beating his wings. This summer, Andy watched three young mockingbirds learning to fly. The little beauties needed weeks of practice and experience to become expert pilots.
A bird must learn how the air moves. For he uses wind direction and rising air currents to lift himself and stay aloft. Slow motion cameras show how he uses the air with each wing beat. The up beat is a quick let flack with the long wing feathers spread out like fingers to/the air through.
The down beat is slower. Now the fingery feathers are closed together and the windy air cannot get through them. The wings are bent at what would be the elbow joint to gather a scoop of air and pile it into a cushion below him.
As he pushes himself forward, he uses this cushion of denser air to hoist himself one step higher. With each down beat up he goes on the steps of his invisible ladder into the blue.
The proud eagle and the vulture, the graceful gull and the wandering albatross are soaring birds. But, like his small, twittering relatives, a soaring bird must also beat his wings to get off the ground and climb upstairs. Once aloft, he glides and glides on his outstretched wings. Actually, he is slowly, slowly falling and may have to start his climb all over again. Sometimes he finds a current of rising air to lift his light body. This fine, flying carpet may keep a soaring bird from drifting down for a long, long time.
Mother Nature has made it easy for a bird to fly. His body is light and stream‑lined. Many of his slender bones are hollow and filled with pockets of air, In his body there are other air sacs which connect with the lungs. All this air makes him light and buoyant. His soft, warm feathers add little or nothing to his weight. But with all these advantages, a young bird must still study hard and practice the skills of flight.