Birds belong to the group of the land vertebrates. The science of birds is called ornithology. Birds live on all continents and there are about 9000 different living bird species.
Feathers: Body is covered by feathers
Beak: without teeth
Flight capability: almost all birds a able to fly
Skeleton: hollow bones
Heart rate: very high
Sense organ: The eye is the best developed organ.
Voice: lower part of the larynx
Lung: air sacs
