Elk range in forest and forest-edge habitat, feeding on grasses, plants, leaves and bark. Male elk have large antlers which are shed each year. Males also engage in ritualized mating behaviors during the rut, including posturing, antler wrestling (sparring), and bugling, a loud series of vocalizations which establishes dominance over other males and attracts females.
Although native to North America and eastern Asia, they have adapted well to countries where they have been introduced, including Argentina, Australia and New Zealand. Their great adaptability may threaten endemic species and ecosystems into which they have been introduced. Elk are susceptible to a number of infectious diseases, some of which can be transmitted to livestock. Efforts to eliminate infectious diseases from elk populations, largely through vaccination, have had mixed success.
Some cultures revere the elk as a spiritual force. In parts of Asia, antlers and their velvet are used in traditional medicines. Elk are hunted as a game species; the meat is leaner and higher in protein than beef or chicken. It was long believed to be a subspecies of the European red deer (Cervus elaphus), but evidence from a number of mitochondrial DNA genetic studies beginning in 1998 indicate that the two are distinct species. Key morphological differences that distinguish C. canadensis from C. elaphus are the former's wider rump patch and paler-hued antlers.
A bull (male) elk's antlers may reach 4 feet (1.2 meters) above its head, so that the animal towers 9 feet (2.7 meters) tall. Bull elk lose their antlers each March, but they begin to grow them back in May in preparation for the late-summer breeding season.
In early summer, elk migrate to high mountain grazing grounds where the cows (females) will give birth. Each cow typically has a single calf, which can stand by the time it is 20 minutes old. During the late summer breeding season the bugling of bull elk echoes through the mountains. These powerful animals strip the velvet off their new antlers using them in violent clashes that determine who gets to mate with whom. Males with the bigger antlers, typically older animals, usually win these battles and dominate small herds.
In the winter, elk reconvene into larger herds, though males and females typically remain separate. The herds return to lower valley pastures where elk spend the season pawing through snow to browse on grass or settling for shrubs that stand clear of the snow cover.
Dominant bulls follow groups of cows during the rut, from August into early winter. A bull will defend his harem of 20 cows or more from competing bulls and predators.Only mature bulls have large harems and breeding success peaks at about eight years of age. Bulls between two and four years and over 11 years of age rarely have harems, and spend most of the rut on the periphery of larger harems. Young and old bulls that do acquire a harem hold it later in the breeding season than do bulls in their prime. A bull with a harem rarely feeds and he may lose up to 20 percent of his body weight. Bulls that enter the rut in poor condition are less likely to make it through to the peak conception period or have the strength to survive the rigors of the oncoming winter.
Adult elk usually stay in single-sex groups for most of the year. During the mating period known as the rut, mature bulls compete for the attentions of the cow elk and will try to defend females in their harem. Rival bulls challenge opponents by bellowing and by paralleling each other, walking back and forth. This allows potential combatants to assess the other's antlers, body size and fighting prowess. If neither bull backs down, they engage in antler wrestling, and bulls sometimes sustain serious injuries. Bulls also dig holes in the ground, in which they urinate and roll their body. A male elk's urethra points upward so that urine is sprayed almost at a right angle to the penis. The urine soaks into their hair and gives them a distinct smell which attracts cows.
Bulls have a loud vocalization consisting of screams known as bugling, which can be heard for miles. Bugling is often associated with an adaptation to open environments such as parklands, meadows, and savannas, where sound can travel great distances. Females are attracted to the males that bugle more often and have the loudest call. Bugling is most common early and late in the day and is one of the most distinctive sounds in nature, akin to the howl of the gray wolf.