Question
How do tthe air sacs of birds help make the body lighter?
air in the bones lighten the wholww skeleton:
http://www.backyardnature.net/birdbone.htm
But the 9 breathing air sacs do not really lighten the bird except to possibly allow smaller lungs:
http://www.people.eku.edu/ritchisong/birdrespiration.html
air in the bones lighten the wholww skeleton:
http://www.backyardnature.net/birdbone.htm
But the 9 breathing air sacs do not really lighten the bird except to possibly allow smaller lungs:
http://www.people.eku.edu/ritchisong/birdrespiration.html