Thursday, 13 November 2014

Birds

Birds (class Aves or clade Avialae) are featheredwingedtwo-leggedwarm-bloodedegg-laying vertebratesModern birdsare characterised by feathers, a beak with no teeth, the laying of hard-shelled eggs, a high metabolic rate, a four-chamberedheart, and a lightweight but strong skeleton. Extant birds have more or less developed wings; the most recent species without wings was the moa, which is generally considered to have become extinct in the 16th century. Wings are evolved forelimbs, and most bird species can flyFlightless birds include ratitespenguins, and diverse endemic island species. Some species of birds, particularly penguins and members of the Anatidae family, are adapted to swim. Birds also have digestive andrespiratory systems that are uniquely adapted for flight. Some birds, especially corvids and parrots, are among the mostintelligent animal species; several bird species make and use tools, and many social species culturally transmit knowledge across generations.Bird Diversity 2013.png

Wednesday, 5 November 2014








I have ever seen this plant but now I have this