Gaur are said to look like water buffalo at the front and domestic cattle at the back due to their heavily muscled and enlarged forequarters compared to their relatively small hindquarters. They are the heaviest and the most powerful of all wild cattle, and are among the largest living land animals. Only elephants, rhinos and hippos consistently grow larger, and the weight of the largest subspecies of gaur roughly matches that of the giraffe.
Gaur herds are led by an old adult female (the matriarch). Adult males may be solitary. During the peak of the breeding season, unattached males wander widely in search of receptive females. No serious fighting between males has been recorded, with size being the major factor in determining dominance. Males make a mating call of clear, resonant tones which may carry for more than 1.6 km (0.99 mi). Gaur have also been known to make a whistling snort as an alarm call, and a low, cow-like moo.
Due to their formidable size and power, gaur have few natural enemies. Leopards and dhole (Indian wild dog) packs occasionally attack unguarded calves or unhealthy animals, but only the tiger and the saltwater crocodile have been reported to kill a full-grown adult. When confronted by a tiger, the adult members of a gaur herd often form a circle surrounding the vulnerable young and calves, shielding them from the big cat.
There are several cases of tigers being killed by gaur. In one instance, a tiger was repeatedly gored and trampled to death by a gaur during a prolonged battle.