Gaur

The gaur, or Indian bison, is the largest wild cattle species in the world. It is massively built, with a high ridge on the back behind the shoulders, a deep dewlap and a bony ridge between the horns that gives the head a dished profile. Adult bulls are dark brown, becoming almost black with age, while cows and young are paler and sometimes reddish. Both sexes have an ash-grey or dirty-white forehead, a pale muzzle and white or tan 'stockings' on the lower legs. The horns are pale green or yellow with black tips and curve upwards and inwards (Wikipedia, general species account).

Gaur live in herds led by an old female, usually of about eight to eleven animals with a single bull, though herds sometimes merge into groups of 50 or more. Bulls wander between herds in the breeding season, when their resonant mating call carries more than 1.6 km, and otherwise live alone or in bachelor groups. Herds walk a few kilometres a day and gather near water in the dry season. Where they are disturbed they become largely nocturnal (Wikipedia, general species account).