Bird is a vertebrate animal, belonging to the phylum Chordata, the subphylum Vertebrata, and the class Aves. They have special characteristics, such as forelimbs turning into wings, bodies covered with feathers, highly developed heart and respiratory systems, and special structures adapted to flying and inhabiting different environments. Unlike mammals and reptiles, birds lay eggs and the chicks need to be cared for and fed by their parents after they hatch. All in all, birds are incredibly diverse, unique, and beautiful animals.
