Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. The study of birds is called ornithology.

Feb 11, 2026 · 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

Jan 24, 2026 · 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 …

鸟类（学名：Aves）是脊椎动物亚门鸟纲的温血卵生动物，全身覆盖羽毛，前肢特化为翼，骨骼中空且胸骨具龙骨突，心脏具两心房两心室，体温恒定约42℃。现存约9000种，分为平胸总目（鸵鸟等）、 …

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The new illustrated Birds of the World Phylogeny Explorer lets users trace any bird’s lineage, compare species relationships, and explore major evolutionary milestones with a click of a button.

The smallest is the two-inch-long bee hummingbird. Everything about the anatomy of a bird reflects its ability to fly. The wings, for example, are shaped to create lift.

May 6, 2025 · With their populations constantly declining, 1,227 bird species were listed as threatened by BirdLife International and the IUCN in 2009. However, conservation efforts are being undertaken …

Oct 25, 2025 · Although all bird species have wings, some are actually flightless animals that only use their wings for balance and not for flying. Other birds, such as penguins, use their wings for swimming.