Birds are also known as Aves and found globally. They range from small to different sizes and shapes. Birds are a group of Endothermic vertebrates which means they can @@. They are basically characterized by feathers, toothless beaked jaws, hard shelled eggs laid by them. They possess a high metabolic rate and a four chambered heart along with very lightweight skeleton. Their size varies in between 5cm to 2.75m.
Nearly 10 thousand species are found in the globe. They are one of the closest relatives of Crocodiles.