Our Animals - Rocky Mountain Elk
Our Animals > Rocky Mountain Elk
The elk, or wapiti (Cervus canadensis), is one of the largest species of deer in the world and one of the largest mammals in North America and eastern Asia. In the deer family (Cervidae), only the moose, Alces alces (called an "elk" in Europe), is larger, and Cervus unicolor (the sambar deer) can rival the C. canadensis elk in size. Elk are almost identical to red deer found in Europe, of which they were long believed to be a subspecies; however, mitochondrial DNA evidence from 2004 strongly suggests they are a distinct species.
Elk range in forest and forest-edge habitat, feeding on grasses, plants, leaves, and bark. Although native to North America and eastern Asia, they have adapted well to countries where they have been introduced, including New Zealand, Australia and Argentina. Their great adaptability may threaten endemic species and ecosystems into which they have been introduced.
Male elk have large antlers which are shed each year. Males 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.
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.
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 to 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.
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.
Reproduction and life cycle
Female nursing young. Female elk have a short estrus cycle of only a day or two and matings usually involve a dozen or more attempts. By the fall of their second year, females can produce one and, very rarely, two offspring, though reproduction is most common when cows weigh at least 200 kg (450 lb). The gestation period is 240 to 262 days and the offspring weigh between 15 and 16 kg (33 to 35 lb). When the females are near to giving birth, they tend to isolate themselves from the main herd, and will remain isolated until the calf is large enough to escape predators. Calves are born spotted, as is common with many deer species, and they lose their spots by the end of summer. Manchurian wapiti may retain a few orange spots on the back of their summer coats until they are older. After two weeks, calves are able to join the herd and are fully weaned at two months of age. Elk calves weigh as much as an adult white-tailed deer by the time they are six months old. The offspring will remain with their mothers for almost a year, leaving about the time that the next season's offspring are produced. The gestation period is the same for all subspecies.
Elk live 20 years or more in captivity but average 10 to 13 years in the wild. In some subspecies that suffer less predation, they may live an average of 15 years in the wild.
Protection from predators
Male elk retain their antlers for more than half the year and are less likely to group with other males when they have antlers. Antlers provide a means of defense, as does a strong front-leg kick, which is performed by either sex if provoked. Once the antlers have been shed, bulls tend to form bachelor groups which allow them to work cooperatively at fending off predators. Herds tend to employ one or more scouts while the remaining members eat and rest.
After the rut, females form large herds of up to 50 individuals. Newborn calves are kept close by a series of vocalizations; larger nurseries have an ongoing and constant chatter during the daytime hours. When approached by predators, the largest and most robust females may make a stand, using their front legs to kick at their attackers. Guttural grunts and posturing effectively deter all but the most determined predators. Wolf and coyote packs and the solitary cougar are the most likely predators, although brown and black bears also prey on elk. Coyote packs mostly prey on elk calves, though can sometimes take a winter-weakened adult. In the Greater Yellowstone Ecosystem which includes Yellowstone National Park, bears are the most significant predators of calves. Major predators in Asia include the wolf, dhole, brown bear, Siberian tiger, Amur leopard, and snow leopard. Eurasian lynx and wild boar sometimes prey on Asian elk calves. Historically, tigers in Baikal fed on Manchurian wapiti, and continue to do so in the Amur region.
As is true for many species of deer, especially those in mountainous regions, elk migrate into areas of higher altitude in the spring, following the retreating snows, and the opposite direction in the fall. Hunting pressure also impacts migration and movements. During the winter, they favor wooded areas and sheltered valleys for protection from the wind and availability of tree bark to eat. Roosevelt elk are generally non-migratory due to less seasonal variability of food sources.
Elk are ruminants and therefore have four chambered stomachs. Unlike white-tailed deer and moose which are primarily browsers, elk have a similarity to cattle as they are primarily grazers, but like other deer, they also browse. Elk have a tendency to do most of their feeding in the mornings and evenings, seeking sheltered areas in between feeding to digest. Their diets vary somewhat depending on the season with native grasses being a year round supplement, tree bark being consumed in winter and forbs and tree sprouts during the summer. Elk consume an average of 20 pounds (9.1 kg) of various foodstuffs daily. Particularly fond of Aspen sprouts which rise in the Spring, elk have had some impact on Aspen groves which have been declining in some regions where elk exist.