national aviary >> wings to fly

As a bird flaps its wings, the primary flight feathers act like an airplane propeller. These feathers
are angled so the low-pressure area of the feather is towards the front of the bird, pulling the bird
forward. The main lift and propulsion comes on the down stroke of the wings. Lift is also obtained
from the secondary flight feathers as the wings are pulled back up.

LIFT OFF!
How do birds do it? You can figure it out by building different bird models, with different features that may or may not help it fly.

A BIG ENOUGH WING
Hummingbirds beat their tiny wings hundreds of times a second. Condors glide for hours without flapping once. Compare the biggest and smallest wings..

MIGRATION HOPSCOTCH
Think flying is hard? How about flying thousands of miles every spring and fall, navigating to the same spot year after year. Play this game to try to make the journey.

SHAPES AND SIZES
A bird's wings and an airplane's wings both have to keep it aloft. Both are also designed to fly specific ways. See how different wing types are good for different kinds of flight.

Secondary flight feathers make up the "arm" part of the bird's wing. This part of the wing is shaped to offer lift for gliding flight. Not much thrust is generated from flapping.

Compare the albatross and hummingbird wings, below. An albatross flies by gliding, so it has a great number of secondary feathers which forms more surface area to create more lift. On the hummingbird, which has to flap at incredible speeds, the "hand" part makes up most of the wing.

This part of the wing keeps the bird flying efficiently. Other feathers do the work of keeping the bird in the air. Covert feathers are softer than flight feathers.

They create a smooth area for the air to flow over the wing providing lift.

The alula is a special part of the wing that can be hard to notice. It has a separate phalanx (finger bone) and muscles that allow the bird to use their alula to help them control their flight. Like the flaps on airplane wings, the alula helps keep the birds from stalling, and is useful in slow manoeuvers.

Birds control their flight by changing the shape of their wings.

Primary flight feathers make up the "hand" part of the wing. This part of the wing provides thrust from flapping. The hummingbird's wing, seen below, is adapted for flapping flight, with shrunken arm bones and very developed hand bones.

Compared to a human, the bones in the hand and wrist have mostly fused together.