They are herbivores, feeding on grass, twigs, leaf shoots of bushes and bark. They paw with their front feet to uncover any grass or other natural foods such as brouse, clover, vetch or forbs. In winter, they make necessary adjustments to their eating habits to make use of what is available. When raised in captivity, elk should be fed a supplement of alfalfa, clover hay and any other hay with corn, as well as a balanced diet of grain supplements. Salt and mineral blocks also need to be readily available.
Elk are gregarious, with each sex forming separate herds for most of the year.
Most herds of elk are led by an older cow elk with the bull herding the group. A large bull elk will herd together several cow elk for mating. The smaller bulls will be run off by the older male, who can be quite aggressive and dangerous while in rut. They have been known to tear down deer fences and even kill other animals with their fighting. The smaller bulls will herd together and attempt to breed the cows from time to time.