Origin of birds
Flight Adaptation
Mechanism of Flight
Perching Mechanism
Reproduction
Migration
Economic Importance
FAQ'S
PROFILE
Modes Of Flight
There are three or four chief kinds of flight in birds, and all the kinds may be used at different times by the same bird. Also, in all types of flight, the tail helps to support and balance the body, serving as a rudder.
1.Gliding Or Skimming
The simplest and probably the most primitive mode of flight is gliding. Birds hold their wings spread motionless and glide for a considerable distance without flapping them, although it may alter the curvature of their surface. Gliding depends for its movement on the velocity acquired by previous strokes, or by descending from a higher to a lower level or by making use of air-currents. The gliding flight can only be exhibited for a short time; bird soon loses velocity or height. Gliding can be readily observed in shore-birds coming in for a landing; in ducks, gulls, and herons over water; in swallows and swifts in the air; in pigeons gliding from there loft to the ground; or in a falcon swooping upon its quarry.
2.Soaring Or Sailing
It is the most remarkable and highly specialized mode of flight, illustrated by birds with a large wing-span, such as albatross, vulture, falcon, stork, crow etc. The bird, usually at a high level, describes great circles without any movement of the wings, without losing its velocity or vertical position as is the case in gliding. It is possible only because the weight of the bird is supported upon upward currents of air. The bird rises without loss of kinetic energy.
3.Flapping
It is the most common or ordinary mode of flight. All birds fly by flapping their wings up and down. Each flapping includes an effective downstroke and a recovery upstroke of the wings. To start with, the wings are held vertically and fully spread. In the downstroke, they move obliquely forward downward and backward, their distal portions tilted upwards. Thus, there is both lift and thrust. In the upstroke, the wings are partly folded and their primary feathers spread out for the air to slip through, thus making it easier to lift them. They move up and backwards. As a net result, the bird will be propelled forwards and sustained in the air. Pigeons can beat their wings at least eight times in one second.
4.Hovering
It is a peculiar variant of flapping flight. In hovering, found in humming birds, the body is kept vertical, while the bird remains poised in the air before a flower or above an object upon the ground, the tips of its wings apparently describing a figure of eight.
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