How
Does A Bird Fly?
Birds are able to fly by flapping their wings, the aerodynamics
of the wing, and by taking advantage of thermal currents. Birds fly by pushing downward with
their wings on the air. This produces an opposite force that “lifts”
the bird into the air. Since a bird's wing is in the shape of an airfoil,
it produces some lift even when the bird is just gliding. They do
this by using special feathers called primaries and secondaries which shape
the wing. When the wing is flapped downward, the primaries act like
an airplane propellor giving the bird a forward motion ; the feather is angled
so that the upper side of the feather has lower air pressure , and creates
lift as the air moves over the wing. The secondaries also help
in causing lift, especially on the upstroke of the wing beat. Some
birds take advantage of rising hot air "thermals" in places such as
shopping centers with asphalt and open
farm fields. While using the rising warm air currents, birds cannot
fly using aerodynamics, but gain altitude by riding the rising air. They
will glide from one "thermal" to another "thermal" . This
is easily observed when a bird is flying in circles and rising.
To make this work, a bird needs some serious muscle power. In addition, birds are well adapted for flight. The bones of many birds are hollow, to eliminate weight but to remain stable and strong. Another factor in how birds are able to fly is their respiratory system. Birds' respiratory systems are more efficient than ours are. Since flying is much more demanding than walking or even running, they have developed two very efficient lungs, and a four chamber heart. This helps them get as much oxygen from the air as possible. That is how birds fly!
To make this work, a bird needs some serious muscle power. In addition, birds are well adapted for flight. The bones of many birds are hollow, to eliminate weight but to remain stable and strong. Another factor in how birds are able to fly is their respiratory system. Birds' respiratory systems are more efficient than ours are. Since flying is much more demanding than walking or even running, they have developed two very efficient lungs, and a four chamber heart. This helps them get as much oxygen from the air as possible. That is how birds fly!
