Cite this page
Edu-Center | Zoology | Birds

What is a bird?

Birds are warm-blooded vertebrates, characterised by having feathers, toothless beaks, the laying of eggs with hard shells, a heart with four chambers, and a lightweight skeleton. Birds are also known as Aves or avian dinosaurs, which isn't just a coincidence--birds are the closest living descendants of dinosaurs! Birds can be found almost anywhere on the earth and include species that range in size from 5 cm tall hummingbird all the way to the 2.75 m tall ostrich.


  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Aves

Cool bird facts

  • It's estimated that there are between 9,000 and 10,000 species of birds, with about 95% of them having been classified and described.
  • Ostriches are the largest bird in the world and have the largest eyes of any land animal. They also lay the largest eggs of any bird and can run up to 97 kph
  • It's estimated that about 20% of bird species migrate every year.
  • Hummingbirds are the only bird that can both hover in place and fly backwards. They also weigh less than a US nickel.
  • Birds' skeletons are made up of ultra-light, hollow bones.
  • Ravens are some of the most intelligent animals in the world, on par with chimpanzees and even toddlers.

Bird sounds in different languages

  • Dutch: Tjiep
  • English: Tweet
  • French: Cui-cui
  • Greek: Tsiou-tsiou
  • Italian: Chip
  • Japanese: Chun-chun
  • Turkish: Jick-jick
  • Spanish: Pio-pio
  • Swedish: Pip-pip

See something this page is missing?

Click here to fill us in.