Bird wiki:
>For other uses, see Bird (disambiguation). Many - see section below. Birds are bipedal, warm-blooded, egg-laying vertebrates characterized primarily by feathers, forelimbs modified as wings, and hollow bones. Birds range in size from the tiny hummingbirds to the huge Ostrich and Emu. Depending on taxonomic viewpoint, there are about 8,800â10,200 living bird species (plus about 120â130 that have become extinct in the span of human history) in the world, making them the most diverse class of terrestrial vertebrates.
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Head wiki:
>For other uses of the word head, see head (disambiguation). In anatomy, the head of an animal is the anterior part (from anatomical position) that comprises the mouth, the brain and various sensory organs (e.g. organs of sight, hearing, smell and taste).
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