Birds are fascinating creatures. They are capable of something man can only dream of: self-propelled, self-sustained, flight. They are reliant only on themselves and their inborn traits and skills to keep them aloft in the air. While man can fly on airplanes or wind surf, it is much different from having wings and truly flying.
While all birds (with a few notable exceptions) can fly, they are not all capable of the same type of flight. Some birds are naturally much more powerful and skilled fliers than others. For example, while both the pigeon and the falcon are both species of birds, the falcon is a far superior flier. When diving, the peregrine falcon can achieve speeds of up to two-hundred miles per hour!
Many of these differences stem from more active lifestyles. Birds like vultures, kites, and eagles do not pick and eat grain on the ground like pigeons do. Nor do they eat insects, as they would have to consume an exorbitant amount to get their daily nutritional needs. Because of this, they hunt small to medium sized game.
The key word there is hunt. Hunting by nature can be a very time-consuming process. Hunting birds need the ability to remain in the air for long periods of time. Not only does flying give them the advantage of a “bird’s eye view”, but it also allows them to pounce on their prey from the air. A falcon in search of prey may spend hours and scour miles worth of ground before finding suitable prey. A carrion bird like a vulture spends long amounts of time finding a carcass to consume. All of these precludes a need to stay in the air for long periods of time without spending an exorbitant amount of energy.
A method birds use to accomplish this is by flying without flapping their wings. This seems counter-intuitive, as without the lift generated by flapping their wings, how can a bird stay in the air? Of course, to initially get off the ground, the bird needs to flap its wings. But once in the air, it is easy to see a bird coast along, only occasionally flapping its wings.
The bird accomplishes this through two methods: gliding and soaring. While these two words may be similar, their method of execution and what they do are quite different. A gliding eagle has its wings outspread, not moving whatsoever. It expends little energy while in this position, while still moving very quickly. While gliding, the bird will lose height at a ratio of 15:1. Essentially, for every 15 feet the bird flies, it loses a foot in height. This is because it is coasting, utilizing its natural light frame optimized for flying to fall very, very slowly. A bird can maintain gliding for some time, a few flaps of its wings will sustain it for quite a while. This enables the bird to travel for miles while expending very minimal amounts of energy.
Soaring is much different from gliding. While gliding the bird merely moves forward and down, with soaring, the bird can also move up. It does this through naturally harnessed lift forces generated by the air. Air pressure changes constantly. As the temperature changes, pockets of air move back and forth, creating wind. Birds take advantage of these wind streams, utilizing them to soar up and down without flapping their wings. One limitation of this is that a bird can only use warm air pockets to soar up and down. This is because warm air pockets are created close to the ground, where it is warmer, and rise up, creating the updraft necessary needed for a bird to soar. This reason is why birds are often seen soaring in circles, they need to keep within the warm air pockets in order to remain aloft without flapping their wings.
Birds in Our World:
Do birds interest you? They are quite fascinating creatures. Some of the most beautiful, exotic animals in the world are birds. Many people make both hobbies and careers around spotting and photographing birds.