Question

Using basic principles of animal form and function, explain why it is not surprising that flightlessness is strongly associated with large body size in birds.

Answer 1

Flightlessness is strongly associated with large body size in birds:

An animal’s size and shape, features often called “body plans” or “designs,” are fundamental aspects of form and function that significantly affect the way an animal interacts with its environment.Bird flight is the primary mode of locomotion used by most bird species. Flight assists birds while feeding, breeding, avoiding predators, and migrating. Bird flight is one of the most complex forms of locomotion in the animal kingdom.

It is thus concluded that the flightlessness is associated with the larger size of the body,although there are a few flightless birds that are smaller.But most of the flightless birds are larger and heavier and thus they can not fly.The bird's physical size and the leg bone and toe structure are interrelated characteristics. Flying birds have light skeletons with many hollow bones. Because ratites do not have to lift their bodies off the ground for flying, however, they have large bodies supported by heavy leg bones and thick strong feet adapted for walking on land.