Elk

The elk, or wapiti (Cervus canadensis), is the second largest species of deer in the world, after the moose, which is, confusingly, often also called elk in Europe. Elk are one of the largest mammals in North America and eastern Asia. Until recently, elk and red deer were considered the same species, however DNA research has indicated that they are different.

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 and Argentina. Their high level of adaptability poses a threat to endemic species and ecosystems where 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 and bugling, a loud series of screams which establishes dominance over other males and attracts females. The bugle call is one of the most distinctive calls in nature.

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.

Early European explorers to North America, who were familiar with the smaller red deer of Europe, believed that the much larger North American animal looked more like a moose, hence they used the common European name for the moose, which is often called an elk. The name elk is from the German word for moose, which is elch. The name wapiti is from the Native American word waapiti, meaning white rump and is of Shawnee Native American origin. The elk is also referred to as the maral in Asia, though this is due to confusion with the central Asian red deer, which is a very similar species.

Cervus genus ancestors of elk first appear in the fossil record 12 million years ago, during the Pliocene in Eurasia, but do not appear in the North American fossil record until the later Pleistocene ice ages when they crossed the Bering land bridge. The extinct Irish Elk (Megaloceros) was not a member of the genus Cervus, but rather the largest member of the wider deer family (Cervidae) known from the fossil record.

There are numerous subspecies of elk: six from North America and five from Asia, although some taxonomists consider them different ecotypes or races of the same species (adapted to local environments through minor changes in appearance and behavior). Populations vary as to antler shape and size, body size, coloration and mating behavior. DNA investigations of the Eurasian subspecies revealed that phenotypic variation in antlers, mane and rump patch development are based on "climatic-related lifestyle factors".

Of the six subspecies of elk known to have inhabited North America in historical times, four remain, including the Roosevelt (C. canadensis roosevelti), Tule (C. canadensis nannodes), Manitoban (C. canadensis manitobensis) and Rocky Mountain (C. canadensis nelsoni). The Eastern elk (C. canadensis canadensis) and Merriam's elk (C. canadensis merriami) subspecies have been extinct for at least a century. Classification of the four surviving North American groups as subspecies is maintained, at least partly, for political purposes to permit individualized conservation and protective measures for each of the surviving populations.

Five subspecies found in Asia include the Altai (C. canadensis sibiricus), the Tianshan (C. canadensis songaricus) and the Asian wapitis (C. canadensis asiaticus), also known as the Siberian elk. Two distinctive subspecies found in China and Korea are the Manchurian (C. canadensis xanthopygus) and the Alashan wapitis (C. canadensis alashanicus). The Manchurian wapiti is darker and more reddish in coloration than the other populations. The Alashan wapiti of north central China is the smallest of all subspecies, has the lightest coloration and is the least studied. Valerius Geist, who has written on the world's various deer species, holds that there are only three subspecies of elk. Geist maintains the Manchurian and Alashan wapiti but places all other elk into C. canadensis canadensis.

Until 2004, red deer and elk were considered to be one species, Cervus elaphus, based on fertile hybrids that have been produced in captivity. Recent DNA studies, conducted on hundreds of samples from red deer and elk subspecies as well as other species of the Cervus deer family, showed that there are three distinct species, dividing them into the east Asian and North American elk (wapiti) (C. canadensis), the central Asian red deer (C. affinis) and the European red deer (C. elaphus).

The previous classification had over a dozen subspecies under the C. elaphus species designation; DNA evidence concludes that elk are more closely related to central Asian red deer and even sika deer than they are to the red deer. Though elk and red deer can produce fertile offspring in captivity, geographic isolation between the species in the wild and differences in mating behaviors indicate that reproduction between them outside a controlled environment would be unlikely.

The elk is a large animal of the artiodactyle ungulate order, possessing an even number of toes on each foot, similar to those of camels, goats and cattle. It is a ruminant species, with a four-chambered stomach, and feeds on grasses, plants, leaves and bark. During the summer, elk eat almost constantly, consuming between 4.5 and 6.8 kg (10 to 15 lb) daily. In North America, males are called bulls, and females are called cows. In Asia, stag and hind, respectively, are sometimes used instead.

Elk are more than twice as heavy as mule deer and have a more reddish hue to their hair coloring, as well as large, buff colored rump patches and smaller tails. Moose are larger and darker than elk, bulls have distinctively different antlers and moose do not herd. Elk cows average 225 kg (500 lb), stand 1.3 m (4-1/2 ft) at the shoulder, and are 2 m (6-1/2 ft) from nose to tail. Bulls are some 25% larger than cows at maturity, weighing an average of 315 kg (650 lb), standing 1.5 m (5 ft) at the shoulder and averaging 2.4 m (8 ft) in length. The largest of the subspecies is the Roosevelt elk, found west of the Cascade Range in the U.S. states of California, Oregon and Washington, and in the Canadian province of British Columbia. Roosevelt elk have been reintroduced into Alaska, where males have been recorded as weighing up to 590 kg (1,300 lb).

Only the males have antlers, which start growing in the spring and are shed each winter. The largest antlers may be 1.2 m (4 ft) long and weigh 18 kg (40 lb). Antlers are made of bone which can grow at a rate of 2.5 cm (1 inch) per day. While actively growing, the antlers are covered with and protected by a soft layer of highly vascularised skin known as velvet. The velvet is shed in the summer when the antlers have fully developed. Bull elk may have six or more tines on each antler, however the number of tines has little to do with the age or maturity of a particular animal. The Siberian and North American elk carry the largest antlers while the Altai wapiti have the smallest. The formation and retention of antlers is testosterone-driven. After the breeding season in late fall, the level of pheromones released during estrus declines in the environment and the testosterone levels of males drop as a consequence. This drop in testosterone leads to the shedding of antlers, usually in the early winter.

During the fall, elk grow a thicker coat of hair, which helps to insulate them during the winter. Males, females and calves of Siberian and North American elk all grow thick neck manes; female and young Manchurian and Alashan wapitis do not. By early summer, the heavy winter coat has been shed, and elk are known to rub against trees and other objects to help remove hair from their bodies. All elk have large and clearly defined rump patches with short tails. They have different coloration based on the seasons and types of habitats, with gray or lighter coloration prevalent in the winter and a more reddish, darker coat in the summer. Subspecies living in arid climates tend to have lighter colored coats than do those living in forests. Most have lighter yellow-brown to orange-brown coats in contrast to dark brown hair on the head, neck, and legs during the summer. Forest adapted Manchurian and Alashan wapitis have darker reddish-brown coats with less contrast between the body coat and the rest of the body during the summer months. Calves are born spotted, as is common with many deer species, and they lose their spots by the end of summer. Manchurian wapiti calves may retain a few orange spots on the back of their summer coats until they are older.

Modern subspecies are descended from elk that once inhabited Beringia, a steppe region between Asia and North America that connected the two continents during the Pleistocene. Beringia provided a migratory route for numerous mammal species, including brown bear, caribou, and moose, as well as humans. As the Pleistocene came to an end, ocean levels began to rise; elk migrated southwards into Asia and North America. In North America they adapted to almost all ecosystems except for tundra, true deserts, and the gulf coast of the U.S. The elk of southern Siberia and central Asia were once more widespread but today are restricted to the mountain ranges west of Lake Baikal including the Sayan and Altai Mountains of Mongolia and the Tianshan region that borders Kyrgyzstan, Kazakhstan, and China's Xinjiang Province. The habitat of Siberian elk in Asia is similar to that of the Rocky Mountain subspecies in North America.

Throughout their range, they live in forest and in forest edge habitat, similar to other deer species. In mountainous regions, they often dwell at higher elevations in summer, migrating down slope for winter. The highly adaptable elk also inhabit semi-deserts in North America, such as the Great Basin. Manchurian and Alashan wapiti are primarily forest dwellers and their smaller antler sizes is a likely adaptation to a forest environment.

Bull elk on a captive range in Nebraska. These elk, originally from Rocky Mountain herds, exhibit modified behavior due to having been held in captivity, under less selective pressureThe Rocky Mountain elk subspecies has been reintroduced by hunter-conservation organizations in the Appalachian region of the eastern U.S., where the now extinct Eastern elk once lived After elk were reintroduced in the states of Kentucky, North Carolina and Tennessee, they migrated into the neighboring states of Virginia and West Virginia, and have established permanent populations there. Elk have also been reintroduced to a number of other states, including Pennsylvania, Michigan and Wisconsin. As of 1989, population figures for the Rocky Mountain subspecies were 782,500, and estimated numbers for all North American subspecies exceeded 1 million. Prior to the European colonization of North America, there were an estimated 10 million elk on the continent. Worldwide population of elk, counting those on farms and in the wild, is approximately 2 million.

Outside their native habitat, elk and other deer species were introduced in areas that previously had few if any large native ungulates. Brought to these countries for hunting and ranching for meat, hides and antler velvet, they have proven highly adaptable and have often had an adverse impact on local ecosystems. Elk and red deer were introduced to Argentina and Chile in the early 20th century. There they are now considered an invasive species, encroaching on Argentinian ecosystems where they compete for food with the indigenous Chilean Huemul and other herbivores. This negative impact on native animal species has led the IUCN to identify the elk as one of the world's 100 worst invaders. Both elk and red deer have also been introduced to Ireland and Australia.

The introduction of deer to New Zealand began in the middle of the 19th century, and current populations are primarily European red deer, with only 15 percent being elk. These deer have had an adverse impact on forest regeneration of some plant species, as they consume more palatable species which are replaced with those that are less favored by the elk. The long term impact will be an alteration of the types of plants and trees found, and in other animal and plant species dependent upon them. As in Chile and Argentina, the IUCN has declared that red deer and elk populations in New Zealand are an invasive species.

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 cows 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 others 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. The urine soaks into their hair and gives them a distinct smell which attracts cows.

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.
 

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.

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 are used with great effectiveness with all but the most determined of predators. Aside from man, wolf and coyote packs and the solitary cougar, are the most likely predators, although brown, grizzly and black bears also prey on elk. 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 the Asian wapiti.

Elk wintering in Jackson Hole, Wyoming after migrating there during the fallThe Greater Yellowstone Ecosystem elk herd numbers over 200,000 individuals and during the spring and fall, they take part in the longest elk migration in the continental U.S. Elk in the southern regions of Yellowstone National Park and in the surrounding National Forests migrate south towards the town of Jackson, Wyoming where they winter for up to six months on the National Elk Refuge. Conservationists there ensure the herd is well fed during the harsh winters. Many of the elk that reside in the northern sections of the Greater Yellowstone Ecosystem migrate to lower altitudes in Montana, mainly to the north and west.

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.

Brainworm (Parelaphostrongylus tenuis) is a parasitic nematode that has been known to affect the spinal cord and brain tissue of elk, leading to death. The nematode has a carrier in the white-tailed deer in which it normally has no ill effects. Nonetheless, it is carried by snails which can be inadvertently consumed by elk during grazing.

Chronic Wasting Disease affects the brain tissue in elk, and has been detected throughout their range in North America. First documented in the late 1960s in mule deer, the disease has affected elk on game farms and in the wild in a number of regions. Elk that have contracted the disease begin to show weight loss, increased watering needs, disorientation and listlessness, and at an advanced stage the disease leads to death. The disease is similar to but not the same as Mad Cow Disease, and no dangers to humans have been documented, nor has the disease been demonstrated to pose a threat to domesticated cattle. In 2002, South Korea banned the importation of elk antler velvet due to concerns about chronic wasting disease.

Brucellosis occasionally affect elk in the Greater Yellowstone Ecosystem, the only place in the U.S. where the disease is still known to exist. In domesticated cattle, brucellosis causes infertility, abortions and reduced milk production. It is transmitted to humans as undulant fever, producing flu-like symptoms which may last for years. Though bison are more likely to transmit the disease to other animals, elk inadvertently transmitted brucellosis to horses in Wyoming and cattle in Idaho. Researchers are attempting to eradicate the disease through vaccinations and herd management measures, which are expected to be successful.