Outline of birds

The following outline is provided as an overview of and topical guide to birds:

Contents

• What type of thing is a bird
• Biological classification
• Nature of birds
• Bird anatomy
• Bird behavior
• History of birds
• Study of birds
• Aviculture
• Threats and conservation
• Artists
• Ornithologists
• Writers
• Birds in culture
• References

Birds (class Aves) – winged, bipedal, endothermic (warm-blooded), egg-laying, vertebrate animals. There are around 10,000 living species, making them the most varied of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from the 5 cm (2 in) bee hummingbird to the 2.75 m (9 ft) ostrich.