The Water Buffalo (Bubalus bubalis), also called domestic water buffalo or Asian water buffalo, is a large bovine native to the Indian Subcontinent and Southeast Asia. It is a large bovid originating in the Indian subcontinent, Southeast Asia, and China. Today, it is also found in Europe, Australia, North America, South America and some African countries. Two extant types of water buffalo are recognized, based on morphological and behavioural criteria – the river buffalo of the Indian subcontinent and further west to the Balkans, Egypt, and Italy, and the swamp buffalo, found from Assam in the west through Southeast Asia to the Yangtze valley of China in the east.
The wild water buffalo (Bubalus arnee) most likely represents the ancestor of the domestic water buffalo. Results of a phylogenetic study indicate that the river-type water buffalo probably originated in India and was domesticated about 5,000 years ago, whereas the swamp-type originated in China and was domesticated about 4,000 years ago. The swamp buffalo dispersed up to the Yangtze River valley between 3,000 and 7,000 years ago.
Water buffaloes thrive on many aquatic plants. During floods, they graze submerged, raising their heads above the water and carrying quantities of edible plants. Water buffaloes eat reeds, Arundo donax, a kind of Cyperaceae, Eichhornia crassipes, and Juncaceae. Some of these plants are of great value to local peoples. Others, such as E. crassipes and A. donax, are a major problem in some tropical valleys and by eating them, the water buffaloes may help control these invasive plants.