Birds are warm-blooded vertebrate animals whose bodies are covered with feathers and whose forelimbs are modified into wings. The Legs of large birds are covered ith scales. Birds can move in other ways to get food or to flee from danger. Some walk or jump, others run and some swim. Although all birds have wings, not all can fly.
How do birds Fly ?
Birds flap their wings to fly. They have powerful pectoral muscles. By pushing the air towards the ground, a bird rises up, move forward by pushing the air behind it. The wings lift it up, with the feathers open to cut through the air, and bring the bird down with the feathers closed to push it towards the ground. Wings are shaped differently, according to different forms of flying. With their large and wide wings, eagles and vultures can reach great heights and glide with currents of air.
Some birds, such as Dove, have to move their wings almost continuously to support the weight of the body. Instead of the usual vibrating movement of the wings, a Hummingbird keeps its wings rigid, but flapping them very, very rapidly. This enables it to remain quite still in the air and even to fly backwards.
What is Feather made of ?
A feather is made of Keratin, a flexible substance which is also present in our fingernails, in skins and animal horns. Hundreds of barbs are joined to the central shaft of the feather and these form a compact surface. The barbs are kept together by tiny hooks, called barbules. The long quill feathers are at the edge of the wing. The covert feathers, on top, give the wing its shape and make it waterproof. The down feathers, short and soft, are next to bird’s flesh and keep the body warm.
Barb:The branches of a feather that grow out of the quill and are held together by barbules in flying birds.
Bill:The jaws of a bird and their horny covering.
Keel:The ridge on the breastbone of a flying bird to which the flying musceles are attached.
Barbules:Hooks that hold the barbs of a feather together in flying birds.
Feathers:Light outgrowths of the skin of birds that cover and protect the body, provide coloration, and aid in flight.
Quill:The hollow central shaft of a feather from which the barbs grow.
Although all birds have wings, not all can fly. The Ostrich can flee from enemies at speed of upto 65km per hour. A Penguin uses its wings as flippers, making it a great swimmer. The flightless kiwi has only tiny, poorly developed wings hidden among its feathers. A chicken can just about manage to rise up from the ground.
Some facts about birds!
- The first chicken came from an egg laid by a bird that was not quite a chicken. Therefore, the egg came first.
- Chickens have over 200 distinct noises they make for communicating.
- Crows have the largest cerebral hemispheres, relative to body size, of any aves family.
- Mockingbirds can imitate many sounds, from a squeaking door to a cat meowing.
- When it comes to birds, the males tend to have the more glamorous feather shape, coloration, songs, and dances. Female birds choose their mate based on this!
- The chicken is the closest living relative to the Tyrannosaurus Rex.
- The penguin is the only bird that can swim, but not fly. It is also the only bird that walks upright.
- Owls turn their heads almost 360° a complete circle but they cannot move their eyes.