Wonder World of Birds - பறவைகளின் அதிசய உலகம் | ROUNDS TUBE
Birds are a group of warm-blooded vertebrates 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. Birds live worldwide and range in size from the 5.5 cm bee hummingbird to the 2.8 m ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. 5 Major Characteristics of Birds are as follows: Feathers. Feathers are the defining characteristic of Aves, found on every living species of bird and no other class of animal. ...Wings. All birds have wings, although not all birds fly. ...Beak. All birds have beaks, or bills, made of a bony core surrounded by a thin layer of keratin. ...Eggs. ...Skeleton. Weasels, snakes and foxes all eat birds – and so do other birds, including hawks, owls and gulls. They all have feathers, wings, and a beak, which means they are all birds. Birds share many characteristics with reptil