Elk

Elk are the largest members of the red deer group of the Artiodactyla. This order has more than two hundred other species including pigs, peccaries, wild boars, warthogs, hippos, cows, goats, sheep, moose, caribou, giraffes, camels, pronghorns, llamas, and deer. Antarctica and Australia are the only continents without any members of Artiodactyla. The fossil record of Artiodactyla dates back at least fifty million years. Female elk (cows) weigh about 360 kilograms at maturity, while males (bulls) weigh about 450 kilograms. Elk calves weigh about 15 kilograms at birth and add 30 kilograms within the next two weeks. Calf survival is highly variable; researchers have reported a range of eighteen to seventy calves at six months for every one hundred cows. The environment and the available nutrition influence all of the average weights above. Physical Characteristics As in many of the deer species, calves have creamy colored spots on their reddish-brown pelage. Bulls are distinctly different from cows in their winter coat color. During the winter, bulls have a dark colored mane, in vivid contrast to their cream colored coats, whereas cows are somewhat darker and lack the mane. Bull elk begin growing antlers in mid to late May, with full antler development finished by August, when velvet rubbing begins. Rubbing the velvet from the antlers, gives an elk a highly polished rack. In aspen trees stands, elk leave scars on the tree trunks at about head height during the removal of the velvet. Antler lengths have been recorded at as much as 150 centimeters. Elk antlers are branched and have tines (points) at their ends. March is the usual month for shedding of the antlers. No good correlation exists between age of the bull and number of tines. After copulation, which usually occurs in September and October, a cow delivers one calf seven months later. Although twins are produced, it is uncommon. Mature cows have an extremely high pregnancy rate, averaging 90 percent in some cases, although older cows (more than eight years old) appear to be less fertile. The decline in fertility may be related to nutritional status. First-year bulls can be fertile but it is more common for bulls in their third year to be the ones participating most in mating events. Bulls mate with more than one cow in their harems, which they defend from other bulls during the rutting season. Presently there is insufficient evidence to support declining bull fertility with increasing age.

Lifestyle
Foraging habits of elk are similar to those of other ungulates. Elk adapt their diet according to the seasons. Some elk populations migrate between spring and winter habitats in search of a better environment and food resources. Other populations do not migrate, remaining in their selected habitat year around because there is adequate forage and cover. During the winter season, dried grasses and shrub branches and shoots are eaten. In the spring and summer, new shoots of grasses and other plants, such as aspens, oaks, and willows are selected. In certain areas of national forests in the southwest, areas are fenced off to prevent elk from grazing on young aspens. Although wildlife experts have reported that elk can live more than twenty years, most do not. At birth the sex ratios are reported to be one male for every female, but this changes dramatically as elk attain adult status (thirty males per one hundred females).Wolves and mountain lions are the primary predators of elk. Elk are social animals, tending to form loose congregations that are segregated by sex most of the year. Herds of elk are not constant; individuals tend to move about, leaving one herd and joining another. During the rutting season, bugling by the bull elk can be heard. In addition to bugling, other behaviors used by males during the rutting season to establish harems and territory include antler rubbing, digging with the forelimbs, posturing with head and neck, and lowering of the ears.