The secret behind the outstanding flight flair of birds is the phenomenal development and structure of their skeletons, which are light yet strong. Most of the bones that form the skeleton are hollow, their interiors webbed or honeycombed across by fine girders of bone to equip some extra strength in the bones. These bones are referred to as 'pneumatic' or air-filled bones.

The bones constituting a bird's skull are light and thin in stark contrast to the solid and heavy structure of the mammals. Even a bird's spine bones are flexible and delicate, the interiors of these bones honeycombed. To maintain the quality of flight that is required from birds to survive, nature has structured their skeleton that way, making them more intricate and meticulous than the structure of an aeroplane. As a result, the flight of a bird is much more adaptable and adroit than the flight of an aeroplane.