The Water Buffalo or domestic Asian water buffalo (Bubalus bubalis) is a large bovine animal, frequently used as livestock in Asia, and also widely in South America, southern Europe, north Africa and elsewhere. In 2000, the United Nations Food and Agriculture Organization estimated that there were approximately 158 million water buffalo in the world and that 97% of them (approximately 153 million animals) were in Asia. There are established feral populations in northern Australia but the dwindling true wild populations are thought to survive in India, Nepal, Bhutan and Thailand. All the domestic varieties and breeds descend from one common ancestor, the Wild Water Buffalo, which is now an endangered species. Buffalo are used as draft, meat and dairy animals. Their dung is used as a fertilizer and as a fuel when dried. In Chonburi, Thailand, and in South Malabar Region in Kerala, India, there are annual water buffalo races. A few have also found use as pack animals carrying loads even for special forces. American bison are known as buffalo in parts of North America, but not normally in other usages; bison are more closely related to cattle, gaur, banteng, and yaks than to Asian buffalo. The water buffalo genus includes water buffalo, tamaraw and anoasâ€”all Asian species. The ancestry of the African buffalo is unclear, but it is not believed to be closely related to the water buffalo.