Evolutionarily derived from dinosaurs, birds are in the class Aves. They have feathers, nearly hollow bones, and no teeth to support a life spent in the air.  Birds are incredibly intelligent and diverse, and are some of my favorite subjects.
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Northern Harrier (Circus hudsonius); Pinnacles National Park, San Benito County, CA
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Yellow-rumped warbler (Setophaga coronata); Santa Cruz, CA
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Varied thrush (Ixoreus naevius); Boulder Creek, CA
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Gadwall (Mareca strepera); Merced National Wildlife Refuge, CA
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Black oystercatcher (Haematopus bachmani); Corcoran Beach, Santa Cruz, CA
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Snowy egret (Egretta thula); Corcoran Lagoon, Santa Cruz, CA