Air Borne

man has probably always been fascinated by the seemingly effortless flight of birds as they move freely from place to place but since birds moved so very quickly it has been difficult to see and understand how they fly like aircraft they must be very specially designed to maneuver successfully in the air slowing down the action with a high-speed camera enables us to see more clearly some of the things which happen when a bird flies the long stiff feathers of the wings and tail are particularly important in supporting the bird in the air permitting it to land safely to take off a game and to turn or change direction whenever it wishes to do so when launching themselves gulls beat their wings against the air with deep powerful strokes on the upstroke the wings are folded so that they rise on edge otherwise they would tend to force the bird downward the bird is a nearly perfect flying machine the body is beautifully streamlined being pointed at both ends and tapering backward like a teardrop from the broad rounded breast well forward when coming in for a landing a bird must beat its wings against the air to break its forward and downward speed so that it can come to rest more gently crash landings could be very dangerous whenever the wings are pumped upwards and downwards or forwards and backwards the stiffer primary feathers at the ends of the wings move farther and faster than the feathers closer to the body it is the feathers at the ends of the wings which are largely responsible for rowing the bird forward through the air the entire wing of the bird can be very flexible powerful muscles and strong tendons can move the different parts freely when necessary feathers are amazingly flexible and elastic under pressure they can be bent and twisted but immediately returned to their former shape and position when the pressure is off when taking off the powerful downbeats of the wings must overcome the force of gravity and lift the bird into the air once it has gained some speed and begins to cruise wing beats are more shallow at times the wings may be held stiffly so that the flow of air over them keeps the bird moving steadily forward gannets usually nest on rocky islands when returning to the colony they turn into the wind allowing the strong sea breeze to whip over their long wings and tail this together with the sharply bent tail checks their forward speed before dropping to the ground brown pelicans often glide for hundreds of yards low over the sea the wings held at just the right angle to hold them in place they put on the brakes by beating heavily against the air [Applause] though very heavy birds brown pelicans fly easily once under way they often have to paddle across the surface to get up enough speed to become airborne it is truly amazing how easily these great birds maneuver when diving for fish white pelicans may glide down very steeply on stiff outstretched wings they are under perfect control Osprey or fish sharks just high in the tops of trees later in the season they will need these long well-developed wings when carrying heavy fish back to the chicks in flight the feathers on the wingtips often twist and separate allowing the air to rush through marsh Hawks hold the wings well above the body as they sail over fields in search of mice and voles this helps to keep them from being blown off balance by sudden gusts of wind flying squirrels live in open woodlands where the trees are some distance apart they'd live from tree to tree on fur colored wings which are stretched between wrist and ankle during long lives the front feet are turned sharply inward and the hind feet outward this keeps the wings fully spread for increased support the tail helps to control the direction of the glide the large eyes tell us that these animals carry on most of their activities at night Blue Jays sometimes lift off sideways writing themselves as soon as they get into the air evening grosbeaks come readily to feeding stations using the wings and tail they are able to hover circle land gently and take off again with the greatest of ease they can just about turn on a dime very little of this can be seen at normal speed hummingbirds are the smallest birds in the world some of them weighing as little as a dime they are in many ways our most exciting fires at normal speed their wings move so rapidly that they are just a blur even slowed down their wings move with fantastic speed it is hard to believe that these little elves can move their wings at 250 strokes per second the brighter males are much more colourful than their grabber mates they can move backward and forward just by changing the angle of the beating wings but more often the tale comes into play at such times [Music] by pushing the tail sharply against the air in front the Hummer is forced backwards forward motion is accomplished by pushing the tail backward against the air when the wing beats are slowed down 20 times it can be seen that hummingbirds do not always use both wings exactly together [Music] hummingbirds can fly in any direction forward backward downward upward sideways or at any angle in between it is little wonder that it is possible to see them engaged in a light-hearted aerial ballet a powerful thrust of the legs launches the Red Wing easily the broad wings and tail help him to land as easily as an airborne feather on short flights broadly spread throughout to most people pigeons are very familiar birds making their homes on farms in villages and even in large cities but their actions too are so quick that the naked eye cannot see what is actually happening again slowing them down with a high-speed camera reveals some of their secrets they launch themselves almost vertically the wings pumping powerfully forwards and backwards the wing beats are so full that the tip strike together above and below the body the stiff feathers at the ends of the wings act like helicopter blades pulling the birds into the air in steady flapping flight the wing beats level out smoothly in preparation for landing the tail is broadleaf and and ready to do its work since the bird is moving rapidly forward it is necessary to apply the brakes quickly the bird does this by switching into a vertical position and pumping its wings strongly against the air he uses both wings and tail for turning the tail is serving both as a brake and as a rudder for steering pigeons often glide on stiff set wings on approaching the target they sometimes side-slit to lose height quickly the feather is covering most of the body are well suited for the many purposes they serve they not only assist in streamlining but keep the bird warm and dry enabling numbers of them to live successfully even in regions near the North and South Poles feathers are unexpectedly strong for their weight they are so durable but they permit many birds to migrate for tens of thousands of miles before it is necessary to replace them at the end of the year unlike the propellers and airplanes the living wings of birds can change their shape dramatically whenever the need arises it is clear that in order to become airborne in order to move forward or in any other direction in order to land successfully at the end of a flight a bird must be able to push against the surrounding air it is also clear that most of this pushing is done with the marvelous wings the large muscles in the breasts provide the power the shock of landing is absorbed by the extended legs though living in the space age we still have much to learn about what it means to have the freedom of the Airways without mechanical [Music] [Applause]