Birds of a feather are still birds
October 7, 2001

Only birds have feathers. The basic kinds of wing feathers are the same in all birds. How they are shaped and arranged varies according to the species.

In general there seems to be four basic wing shapes in birds. The most common is the elliptical, found in birds that have to make their way through openings in leafy branches. This type of wing is comparatively broad in relation to its length. The shape allows the bird a high amount of lift. Most perching birds have this shape, as well as chickens, pheasants and quail that need lift for their heavier bodies.

Slots are spaces between the feathers at the ends of the wings. This characteristic resembles a Venetian blind. More than half of a catbirds' wing is given over to slots.

Another type of wing is the glider type, where the length is much greater than the width. These are the wings of the great bird gliders, such as the albatross. The wandering albatross has a wingspan of 11 feet and less than a foot wide. These birds can soar for hours with barely a wing beat, using even the smallest amount of updrafts created by wind and wave.

The third basic type of wing is the high-speed wing, long and relatively slim, often with swept back hands without slotting. These wings can be found on a variety of birds from falcons to hummingbirds. They are suited for fast level flying. Peregrine falcons are said to fly normally about 40 to 60 miles per hour, but can attain speeds of 200 miles per hour in their dives after prey.

Chimney swifts are noted for their endurance. It is believed they can fly day and night as they seek flying insects for food.

Hummingbirds are unique. They are master hoverers. They have acquired a flight pattern similar to that of helicopters, enabling them to fly directly up, sideways and even backwards at will. With wing beats at 70 per second, they can attain a speed of 30 miles per hour.

The fourth basic wing type is the slotted high-lift wing of eagles and other birds of prey. The wing ratio results in a great deal of lift. These birds are great soarers, but lift also enables them to carry fairly heavy prey while flying.

It is the manipulation of feathers, by the birds and the air that allows for the maneuvers of birds in flight. Each feather is aerodynamically structured. The forward vein is wider than the rear one. Air pressure difference allows for the twisting of the feathers.

Most birds have 10 primary feathers on each wing. These are the propeller feathers. Secondary feathers, which are the lift feathers on the arm, vary widely depending on the length of the wing. Tiers of covets on top and under the wing lend strength. In spite of their importance, the flight feathers are only a small number compared to the rest of those on the bird. Preening and caring for these endowments can keep a bird busy in between flights.

Acknowledgements: Chhapter on "Flight," Smithsonian book of Birds, "Lords of the Air"---Jake Page and Eugene S. Morton