Birds

Birds (class Aves) are bipedal, endothermic (warm-blooded), vertebrate animals that can lay eggs. There are around 10,000 living species, making them the most diverse biped vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Birds range in size from the 5 cm (2 in) Bee Hummingbird to the 2.7 m (9 ft) Ostrich. The fossil record indicates that birds evolved from theropod dinosaurs during the Jurassic period, around 150–200 Ma (million years ago). The earliest known bird is the Late Jurassic Archaeopteryx, c 155–150 Ma. Reverse genetic engineering and the fossil record both demonstrate that birds are modern feathered dinosaurs, having evolved from earlier feathered dinosaurs within the theropod group, which are traditionally placed within the saurischian dinosaurs.

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 birds have forelimbs modified as wings and most can fly, with some exceptions including 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 undertake long distance annual migrations, and many more perform shorter irregular movements. Birds are social; they communicate using visual signals and through calls and songs and participate in social behaviours including cooperative breeding and hunting, flocking, and mobbing of predators. The vast majority of bird species are socially monogamous, usually for one breeding season at a time, sometimes for years, but rarely for life. Other species have breeding systems that are polygynous ("many females") or, rarely, polyandrous ("many males"). Eggs are usually laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching.

Many species of birds are of economic importance, mostly as sources of food acquired through hunting or farming. Some species, particularly songbirds and parrot, 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.

.The country with the most species of birds is Colombia with a record 1,871 species.While the United States ranks 11th with 1,114 species.There are many different varieties of these spectacular and beautiful creatures from all over the world.

Top 50 countries with the biggest amount of birds

 * 1) Colombia 1,821
 * 2) Peru 1,781
 * 3) Brazil 1,712
 * 4) Indonesia 1,604
 * 5) Ecuador 1,515
 * 6) Bolivia 1,414
 * 7) Venezuela 1,392
 * 8) China 1,221
 * 9) India 1,180
 * 10) Congo Dem Rep 1,148
 * 11) United States 1,114
 * 12) Kenya 1,103
 * 13) Tanzania 1,056
 * 14) Myanmar 1,047
 * 15) Argentina 1,038
 * 16) Mexico 1,026
 * 17) Uganda 1,015
 * 18) Thailand 971
 * 19) Sudan 952
 * 20) Cameroon 936
 * 21) Angola 930
 * 22) Panama 904
 * 23) Nigeria 899
 * 24) Nepal 864
 * 25) Australia 851
 * 26) Ethiopia 839
 * 27) Costa Rica 838
 * 28) Vietnam 837
 * 29) South Africa 829
 * 30) Guyana 786
 * 31) Zambia 770
 * 32) Malaysia 746
 * 33) Ghana 729
 * 34) Papua New Guinea 720
 * 35) Laos 704
 * 36) Ivory Coast 702
 * 37) Honduras 699
 * 38) Paraguay 696
 * 39) Mozambique 685
 * 40) Guatemala 684
 * 41) Suriname 674
 * 42) Rwanda 665
 * 43) Central African Republic 663
 * 44) Zimbabwe 661
 * 45) Malawi 658
 * 46) Russia 645
 * 47) French Guiana 644
 * 48) Somalia 642
 * 49) Guinea 640
 * 50) Gabon 632