Question

Essay on world of birds

Answer 1

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.

Answer 2

Answer:

Birds are a group of warm-blooded vertebrates constituting the class Aves, characterized by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton.