Birds are members of the class Aves, which boasts over 10,000 species. Most birds are able to fly, but some, like ostriches, kiwis, penguins, and emus, have wings but cannot fly, and other birds are far better at swimming than they are at flying.
Birds are members of the class Aves, which boasts over 10,000 species. Most birds are able to fly, but some, like ostriches, kiwis, penguins, and emus, have wings but cannot fly, and other birds are far better at swimming than they are at flying.