Animal genetic resources for food and agriculture crop and livestock species in the early neolithic time period changed our human evolution and lifestyles. This ability to control food production led to major demographic, technological, political and military changes. Consecutively, thousands of years of natural and human selection, genetic drift, inbreeding, and crossbreeding have contributed to the diversification of animal genetic resources and increased the variety of environments and production systems that livestock keeping takes place. Relatively few species have been domesticated; out of the world's 148 non-carnivorous species weighing more than 45 kg, only 15 have been successfully domesticated. The proportion of domesticated birds used for food
Human uses of birds to mimic speech. Among reasons for their popularity is that they can be kept in homes too small or otherwise unsuitable for dogs or cats. The cagebird trade in some parts of the world threatens certain species with extinction, when birds are illegally captured in the wild. For example, in Indonesia, at least 13 species are close to extinction including the Indonesian national bird, the Javan hawk-eagle, while five subspecies including the scarlet-breasted lorikeet may have become extinct in the wild. Pet birds are kept in their millions, as are domestic fowls, bantams, and pigeons. These last had an important