Birds live worldwide and range in size from the 5.5 cm (2.2 in) bee hummingbird to the 2.8 m (9 ft 2 in) common ostrich. There are over 11,000 living species and they are split into 44 orders. More than …

3 days ago · Bird, any of the approximately 11,200 living species unique in having feathers, the major characteristic that distinguishes them from other animals. They are warm-blooded vertebrates more …

eBird transforms your bird sightings into science and conservation. Plan trips, find birds, track your lists, explore range maps and bird migration—all free.

Use our Bird Guide to identify birds, learn about the life history, listen to the sounds, and watch bird behavior on video--the most comprehensive guide to Nort

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Birds are found worldwide and in all habitats. The largest is the nine-foot-tall ostrich. The smallest is the two-inch-long bee hummingbird. Everything about the anatomy of a bird reflects its...

May 6, 2025 · Birds are warm-blooded vertebrates characterized by feathers on their bodies, toothless beaked jaws, hard-shelled calcareous eggs, and a four-chambered heart with a high rate of metabolism.