Portal:Birds/Intro
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| A Striated Pardalote (Pardalotus striatus) collecting nesting material in its beak. |
Welcome to the Birds Portal! Birds (class Aves) are bipedal, warm-blooded, oviparous vertebrate animals. Most scientists believe that birds evolved from theropod dinosaurs. Ranging in size from tiny hummingbirds to the huge Ostrich and Emu, there are between 9,000 and 10,000 known living bird species in the world, making Aves the most diverse class of terrestrial vertebrate.
A bird is characterized by feathers, a beak with no teeth, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a light but strong skeleton. Most birds have forelimbs modified as wings and can fly.
Birds are important sources of food, acquired either through farming or hunting. Numerous species of birds are also used commercially, and some species, particularly songbirds and parrots, are popular pets. Birds figure prominently in all aspects of human culture from religion to poetry and popular music. Numerous species of birds are threatened with extinction by human activities and efforts are underway to protect them.
