Facts about birds

                                    FACTS ABOUT BIRDS
 
Birds are one of the six basic animal groups. Birds, best known for their ability to fly, are unmatched in their command of the skies. Albatrosses glide long distances over the open sea, hummingbirds hover motionless in mid-air, and eagles swoop down to capture prey with pinpoint accuracy. But not all birds are aerobatic experts. 


Of the 9,865 bird species, 1,227 species are considered threatened with extinction, 838 species are near threatened, 7,735 species are considered to be of least concern, and 65 species lack the data to determine their status. There are also four species of birds that are classified as extinct in the wild. The last living members of those species survive only in captivity.


Feathers are a defining characteristic of the group, meaning simply that if an animal has feathers, then it is a bird. Feathers serve many functions in birds but most notable is the critical role feathers play in enabling birds to fly. In addition to helping to enable flight, feathers also provide protection from the elements. Feathers provide birds with waterproofing and insulation and even block harmful rays from reaching birds' skin.


Eggs vary in size and color depending on species. Although there is a wide range of egg colors, only two pigments contribute to the color of the shell. The first pigment is derived from hemoglobin and the second from bile. Most species lay their eggs in a nest. Nests may vary in size, shape, and construction material, but the most common nest shape is cup-shaped.


Many species of birds migrate to high latitudes to breed during the spring and summer. Then during the fall and winter months they migrate to regions of lower latitude. Many species follow similar routes each year when migrating. These routes are referred to as migratory flyways.


Instead they have bills that are made of the protein keratin. Bird bills come in a variety of shapes and sizes and are adapted to the particular diet of each species. Herons, for example, have a sharp, pointed bill that enable them to capture fish. Finches on the other hand have a short, conical bill that is well-suited for cracking open seeds.


The largest bird is a ostrich.
Ostriches are flightless birds that have a large body, small head, long legs, and a long neck. Although they cannot fly, they are remarkable runners, able to run at speeds of up to 45 mph for half an hour. Adult ostriches weigh between 220 and 350 pounds and measure between 7 and 9 1/4 feet in height.




Written By Laura Klappenbach, About.com Guide (the Arthur of this blog, Mabry Boyle,  took out all the information corresponding to evolution)