Birds

 Birds are feathered, winged, bipedal, endothermic, egg-laying, vertebrate animals. With around 10,000 living species, they are the most speciose class of tetrapod vertebrates. 

Scientific name: Aves Higher classification: Tetrapod Rank: Class Lower classifications: Falconiformes, Owl, Bucerotiformes, Upupiformes, More...    Birds are warm-blooded vertebrate animals that have wings, feathers, a beak, no teeth a skeleton in which many bones are fused together or are absent, and an extremely efficient,, one-way breathing system. Flying birds have strong, hollow bones and powerful flight muscles.   Most birds can fly. Birds have a very strong heart and an efficient way of breathing - these are necessary for birds to fly. Birds also use a lot of energy while flying and need to eat a lot of food to power their flight. Not all flying animals are birds; and not all birds can fly. The ability to fly has developed independently many times throughout the history of the Earth. Bats (flying mammals), pterosaurs (flying reptiles from the time of the dinosaurs), and flying insects are not birds.  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 were 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.   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.   Birds can often safely perch on a power line without being electrocuted. For the bird (or other animal) to be electrocuted, a potential difference must exist across two points of the bird's body (its feet in the case of a bird on a power line). When perching on a single power line, there is no potential difference between the bird's feet, so it is safe. If the bird (or other animal) touches two power lines at a time, or one power line and a ground (like a ground wire or the earth itself), the animal would be electrocuted and die. Many large birds (like eagles and vultures) are electrocuted when their wide wings touch a power line and a ground wire at the same time (often while flying in to land on a power line). Amazon birds    More than 1500 bird species are found in the Amazon Basin, while South America as a whole is home to roughly one-third the world's birds. Many birds found in the Amazon are northern or southern migrants, wintering in or passing though the rainforest at certain times of the year. Macaws are famous for gathering by the hundreds, even thousands, along the clay cliffs of the Amazon river where they feed on minerals which help the birds process toxins found in the seeds they eat. The world's rarest bird is Spix's macaw, a beautiful bird with a dark blue head, a blue body, and a greenish belly with a black mask and bright yellow eye. It has always been rare, limited to palm groves and river edges in small area near the center of Brazil, but recent deforestation, importation of Africaniz ed bees-which took their tree hollows, and over collection for the hobbyists caused this species' demise.