Birds are feathered, winged, bipedal, endothermic (warm-blooded), egg-laying, vertebrate animals. With around 10,000 living species, they are the most speciose class of tetrapod vertebrates. All present species belong to the subclass Neornithes, and 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. The fossil record indicates that birds emerged within theropod dinosaurs during the Jurassic period, around 160 million years (Ma) ago. Paleontologists regard birds as the only clade of dinosaurs to have survived the Cretaceous–Paleogene extinction event 65.5 Ma ago.
Modern birds are characterised by feathers, a beak with no teeth, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a lightweight but strong skeleton. All living species of birds have wings—the now extinct flightless moa of New Zealand being the only exception. Wings are evolved forelimbs, and most bird species can fly. Flightless birds include ratites, penguins, and a number of diverse endemic island species. Birds also have unique digestive and respiratory systems that are highly adapted for flight. Some birds, especially corvids and parrots, are among the most intelligent animal species; a number of bird species have been observed manufacturing and using tools, and many social species exhibit cultural transmission of knowledge across generations.
Birds are of the class Aves.
Many species are of economic importance, mostly as sources of food acquired through hunting or farming. Some species, particularly songbirds and parrots, are popular as pets. Other uses include the harvesting of guano (droppings) for use as a fertiliser. Birds figure prominently in all aspects of human culture from religion to poetry to popular music. About 120–130 species have become extinct as a result of human activity since the 17th century, and hundreds more before then. Currently about 1,200 species of birds are threatened with extinction by human activities, though efforts are underway to protect them.
If you’re not sure what live wallpapers are, they’re a type of application that works on a mobile device using the Android operating system (like your device!). The application works as a wallpaper – providing the background image for the home screen—but also works as a conventional application since it can provide user-interaction with the touch screen (allowing the image to change dynamically, for example) and access other hardware and software features within the device (accelerometer, GPS, network access, etc.).
**Multiple backgrounds!** Switch up the background as often or as little as you like with user-configurable options.
**Power saving features!** This app uses much less power than typical live wallpapers. It will take a bit more power to operate than a normal wallpaper, but much, much less battery power than the average live wallpaper.
**Super easy to use!** Upon install the app will bring up the options menu and then immediately let you set the wallpaper. No hassle and easy to use!
**Translated to 35 languages!** Do you really, really want to learn Russian? We didn’t think so, but it’s available just in case, in any language your phone can display!
Please note that live wallpapers can’t be set automatically. We’ll bring you to the setup screen where you’ll select the live wallpaper. We’d love to do it automatically but Android doesn’t allow it. Select text from Wikipedia, which does not endorse this product. Licensed under the creative commons (creativecommons.org/licenses/by/3.0/). Text at en.wikipedia.org/wiki/Live_Wallpaper and wikipedia.org/wiki/Bird.