Without getting too deep into the science of flight, I decided I would like to try research just a little about the physical adaptations and processes that allows birds the land. The theory that enables one to get a series of photos like the one below.
A front view of a vulture coming into land. Important things to factor in for any landing are: height, speed and wind direction. These are essential so that the bird does not hit the ground hard or topple over on landing.
Having sighted an ideal landing spot the White backed Vulture tucks its wings in and dives down. Birds skillfully use their wings and also their tails to reduce speed, and control their landing, enabling them to descend on a branch in such a way as barely to disturb it. This is quite an acrobatic feat when one considers the speed at which they approach the landing spot. Sometimes birds actually beat their wings opposite the direction of flight to slow themselves down quickly.
A white backed Vulture comes into land on a dead Leadwood tree. All birds have in common legs and feet that act as landing gear. This landing gear helps them take flight from a stationary position and cushions them during landing. The extent to which birds are able to use this landing gear, however, varies among species. For example, in the better fliers, such as hummingbirds, swifts, and swallows, the legs are weaker and less useful as a landing gear; often the larger birds have strong legs but are not especially skillful fliers. The vulture is a point in case.
He opens up his wings. The increased surface area catches the wind acting like a wind break. In landing, birds use their legs and feet both as air brakes and to grasp the perch or surface. Small birds often land by gauging a desired perch and then by flying at a speed approaching zero at or slightly above the area; the legs and feet then serve the simple function of grasping the perch. Obliged to land at high speeds, most large birds use a ballistic approach; they dive at high speed to just below the desired land site and then pull up into a steep climb, resulting in zero speed at the landing site.
And…touchdown. The legs absorb a fair amount of the inertia and are crucial in keeping the bird on the branch.
A high landing speed does not pose a problem for water birds because they can effectively hydroplane to a halt with their large feet, Most large seabirds are adapted to alight on water, but if necessary they can use their landing gear to accomplish adequate, if clumsy, ground landing. Bird’s feet do not have to be webbed to be effective air brakes. The legs of birds of prey are heavy enough to perform this function. The long legs of storks, herons, cranes, and rails are also excellent drag generators when in landing position.
One thing I have never done, but am very tempted to try, is skydiving. If you search online for how these crazy folk land so gracefully you will find a lot of talk about flare and flaring.
“Flare – The act of pulling down the brakes of the canopy in order to slow it down, resulting in an increased angle of attack and reduced descent rate”
Basically these daredevils are mimmicing that which birds have been doing for millennia.
A skydiver makes a gentle landing in an open field – Google Images
Written and photographed by Adam Bannister
Rich Laburn is filmmaker, photographer and writer who is based at Londolozi Game Reserve in South Africa. Spending his time capturing scenes of the wild and communicating the beauty of the African bushveld, he runs the Londolozi Blog as a way to entertain and engage people wishing to visit these wild lands.
