The earliest birds of which we have any record were descended from reptiles and lived about a hundred and thirty million years ago. These first birds had tails like lizards and teeth in their jaws. Over a period of many millions of years, the wings developed at the expense of the tail and the teeth disappeared. Thus birds as we know the today have evolved. They now differ very much from reptiles and it is only because of the research of zoologists one hundred years ago, that they were found to belong to the same class. There are about eight thousand five hundred different species of birds, and the world can be divided up into areas or regions in which a large proportion of birds in those regions are found there and nowhere else. There are six formal regions. The Northern and Southern Hemisphere are divided into two regions each and the Far East is covered by two : -- the Oriental and the Australian. Such divisions are only very rough ones and are not as definite as the rubber producing areas of the Far East would be on a map. The oyster-catcher for example, with its long red bill and pink legs, does not belong anywhere and is as well known in New Zealand or New Guinea as it is in Britain. The house sparrow or starling, very common birds in most parts of Britain is never seen in Scotland. The line which divides the two Far Eastern 'bird regions' passes through the Indonesian Islands, and it is not by chance that it does. It is called the Wallace Lien after the great explorer and naturalist. On one side of it the birds of Bali are completely different from the birds of Lombok on the other side and only twenty miles away.
Flying birds are all physically built for an active life. Their bodies are very muscular with hollow light bones, a sharp keel and a powerful heart. They are nearly always small to reduce weight and are covered with feathers which are light and not only keep the bird warm, but also assist in flight. Feathers are usually attractive...
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