This document discusses the characteristics of birds. Birds have two legs, are warm-blooded, covered in feathers, have hollow bones, wings, come in over 9,000 species, have beaks, and lay eggs. It also mentions specific parts of birds like their beaks, wings, feet, and feathers. Different types of birds are discussed like small and big flying birds, as well as birds that cannot fly and specific birds and their traits like crows, ostriches, eagles, and parrots.