Birds have been around for millions of years , long before there were any human beings .They are believed to have developed from flying reptiles and the Archaeopteryx is the earliest known bird.
Birds are the only animals in the world to have feathers .A bird's feathers is also known as its plumage. Its plumage is made up of two main types of feathers; contour feathers and down. Contour feathers cover the bird. The feathers overlap each other and help t waterproof it. The down is usually found under the contour feathers and it helps to keep the bird warm.
Adult birds moult regularly. This means that they shed their old feathers and grow new ones . Some birds grow feathers of a different colour specially for the breeding season .Birds spend a lot of time keeping their feathers clean. They nibble at each feather and pull each one through its beak.
Most birds take off by jumping into the air but larger birds like swans, geese, and ducks need long runways to gather enough speed to take off . Some birds like penguins and ostriches cannot fly at all. Once n the air, the smaller birds like the sparrow flap their wings fast. Larger birds such as the eagle glides and soars.
