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 …

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

Dec 17, 2025 · 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 …

Explore more than 800 North American bird species, learn about their lives and habitats, and how climate change is impacting their ability to survive.

We believe in the power of birds to ignite discovery and inspire action. Join us on a lifelong journey to enjoy, understand, and protect birds and the natural world.

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

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.

Detailed information for more than 600 North American bird species, including ID help, browse by shape and taxonomy, and deeper articles.

Discover them all with Birds of the World. Species accounts for all the birds of the world.