Birds, also known as Aves, are a group of endothermic vertebrates, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the 5 cm (2 in) bee hummingbird to the 2.75 m (9 ft) ostrich. They rank as the world’s most numerically-successful class of tetrapods, with approximately ten thousand living species, more than half of these being passerines, sometimes known as perching birds. Birds have wings which are more or less developed depending on the species; the only known groups without wings are the extinct moa and elephant birds. Wings, which evolved from forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in flightless birds, including ratites, penguins, and diverse endemic island species of birds. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming.
GReePX is the best spot for beautiful pictures of quotes, love quotes, love images, crafts, diy, and much more. GReePX is an amazing site fo find the best Birds Wallpapers pictures, images, and many other types of blogs and pics. We are dedicated to bringing you only the best images for you to share anywhere you would like including Facebook, Pinterest, Tumblr, Twitter, or even your personal website or blog. We hope you enjoy our large selection of Birds Wallpapers photos, and we encourage you to sign up so you can save all of your favorite pictures and images to your user profile. It's simple! Once signed up just heart your favorite Birds Wallpapers images and they will be automatically stored in your profile.
If this is your first time here don't forget to check back daily because we frequently update the Birds Wallpapers images for Facebook, Pinterest, Tumblr, Twitter.
Birds Wallpapers incoming search terms:
Pictures of Birds Wallpapers, Birds Wallpapers Pinterest Pictures, Birds Wallpapers Facebook Images, Birds Wallpapers Photos for Tumblr. Download free pictures about Birds Wallpapers from GReePX's library of over 99000 public domain photos, illustrations and vectors.