They flap only for liftoff or to gain altitude. When they're high enough, they glide.
ANSWER
It depends on the bird. Some birds, such as most raptors, soar on the air currents like gliders while they search the ground for prey. Some, like Hummingbirds, would drop like stones if they stopped flapping. Some will flap for awhile, then rest as the propulsion carries them forward, and then flap some more.
You really have to check each species of bird in order to find out how that particular species flies.
a bird stays in the air by flapping it's wings. also, the bones in it's body are hollow, making flying much easier for a bird.
i hope this helps :)
they kiss their kissmyass
swallows
Because of their wings and the wind speed outside.
The purpose of the air sacs in a bird is to help digest food into the gizzard, and to help it breathe, and stay in the air longer and more smoothly. Hope this helps!
Air+Lizard= Bird
An Experiment on a Bird in the Air Pump was created in 1768.
15 psi
A humming bird
Egg + air = bird
the air-y bird
Bird=Air+Lizard
air+egg=bird
A bird flies by the use of its wings. Air is pushed downward by the wings. The air then reacts by pushing the bird upward.