why-birds-fly-in-v-formation
Kuşlar neden V Şeklinde Uçar ?Why-birds-fly-in-v-formation
Every formation has a lead bird out front who leads and sets the pace for the others. The first bird has to work the hardest since it flies through undisturbed air. When the lead bird tires, it will move out of the lead position and fall back into one of the lines of the V. Another bird will rapidly move forward to take the lead position to maintain the V formation. The two birds at the end of the V tire more rapidly and rotate frequently with the rest of the flock. The birds in the middle of the formation get the most benefit.
The lead bird breaks up the wall of air that the flocks flies into and experiences the most air drag or air resistance. The resulting swirling air or eddies caused by the lead bird's movements creates a lift or upwash for the birds behind it and so forth. The tubes of circulating air called wingtip vortices are generated as the wings generate lift. One wingtip vortex trails behind the tip of each wing. Each bird positions itself in a staggered position to the bird in front of it to get the extra lift and reduced air resistance or drag. A bird flying in formation therefore expends less energy than when it is flying solo. Another reason for flying in the V formation is that each bird can observe the position and flight direction of the other birds in the flock to avoid collisions, as well as, to keep the flock together.
This illustration shows how wingtip vortices are generated at the tip of the bird's wings. Air moves from the area of high pressure (under the wing) to the area of low pressure (top of the wing) at the tip of the wing. As the wings move through the air, this curling action causes spirals or vortices at the tips of the wings. The rising air or updraft of the vortices shedding off the bird in front will lift up the bird trailing behind it.
Migratory birds take advantage of each other's wingtip vortices by flying in a V formation so all but the leader are flying in the upwash from the wing of the bird ahead. A little upwash makes it a little easier for the bird to support its own weight. It also lowers the heart beats, increases the flying range, and conserves up to 50-70% more energy.
Producing thrust and reducing drag
In most bird species, there are 10 primary feathers along the outer edge of each wing. The primaries propel the bird through the air.
When a Canada goose flaps its wings during flight, several things happen. During the downstroke (power stroke), a wing moves downward and forward producing forward thrust. During the upstroke (recovery stroke), the tips of the primaries separate and these 'slots' allow passage of air through them which reduces friction or drag as the wing comes up.