There are two species of anoa: the Mountain Anoa (Bubalus quarlesi) and the Lowland Anoa (Bubalus depressicornis). Both live in undisturbed forest, and although they are essentially miniature Water Buffalo, are similar in appearance to a deer, weighing 150–300 kg (330–660 lb).

Both are found on the island of Sulawesi in Indonesia; the Mountain Anoa is also found on the nearby island of Butung. They apparently live singly or in pairs, rather than herds, except when the cows are about to give birth. One young is born per year.

Both species of anoa have been classified as endangered since the 1960s and the population continues to decrease. It is believed unlikely that there are more than 5000 animals of each species remaining. Reasons for the decline of the anoa include hunting for hide, horns and meat by the natives (though they were rarely hunted by natives before the introduction of modern firearms); shooting by the military; and loss of habitat due to the advancement of settlement. Currently, hunting is the more serious factor in most areas. The anoa do not appear to be adaptable to humans.

Mountain Anoa are also known as Anoa de Montana, Anoa de Quarle, Anoa des Montagnes, Anoa Pegunungan, and Quarle's Anoa. Lowland Anoa are also known as Anoa de Ilanura or Anoa des Plaines.