A bird is a vertebrate animal belonging to the Vertebrata subphylum of the phylum Chordata. Wings and beaks are unique features of birds. Birds come in many different forms and habits and are found throughout the world. They usually have two wings, two legs, an upright tail, and a body covered with feathers.
Birds can move by flying, swimming, or walking, and have highly developed sensory systems such as vision, hearing, and smell. Many birds also possess excellent intelligence and learning abilities. Birds such as parrots and crows can imitate human speech and solve problems.
As an important link in the biological chain, birds play an irreplaceable role in ecological balance, environmental protection, and human life.
