Vertebrate is a general term for birds.
Oviposition, constant body temperature, covered with feathers.
The front legs become wings and can fly. The hind limb is the foot, which is used for walking or standing. There are no teeth in your mouth. Breathe with your lungs.
Most birds can fly, but some can't, such as chickens, ducks, geese and ostriches. There are many kinds, all over the world.
Birds make our world beautiful with their hard work. It is it, an insignificant role, that makes the world full of vitality.