Big Horn Animals Tiere Natur SelMcKenzie Selzer-McKenzie

Big Horn
Author Selzer-McKenzie
Bighorn sheep (Ovis canadensis)[3] is a species of sheep in North America and Siberia with large horns which can weigh up to 30 pounds (14 kg). Recent genetic testing indicates that there are three distinct subspecies of Ovis canadensis, one of which is endangered: Ovis canadensis sierrae.

The bighorn sheep originally crossed over the Bering land bridge from Siberia: the population in North America peaked in the millions, and the bighorn sheep entered into the mythology of Native Americans. However, the population crashed by 1900 down to several thousand. Conservation efforts (in part, by the Boy Scouts) have restored the population.
Ovis canadensis is one of three species of mountain sheep in North America and Siberia; the other two species being Ovis dalli, that includes Dall Sheep and Stone's Sheep, and the Siberian Snow sheep Ovis nivicola.

The taxononomy of Ovis canadensis continues to be modified as new genetic and morphologic data becomes available but most scientists currently recognize the following subspecies of bighorn:[4][5]

Rocky Mountain Bighorn Sheep (Ovis canadensis canadensis)
Sierra Nevada Bighorn Sheep (Ovis canadensis sierrae), formerly California Bighorn Sheep,[5]
Desert Bighorn Sheep (Ovis canadensis nelsoni)

In addition, there are currently two federally endangered populations:[6]

Sierra Nevada Bighorn Sheep (Ovis canadensis sierrae), recognized as a unique subspecies
Peninsular Bighorn Sheep, a distinct population segment of Desert Bighorn Sheep (Ovis canadensis nelsoni)
Wild sheep crossed the Bering land bridge from Siberia during the Pleistocene (~750,000 years ago) and, subsequently, spread through western North America as far south as Baja California and northern mainland Mexico.[7] Divergence from their closest Asian ancestor (Snow sheep) occurred about 600,000 years ago.[8] In North America, wild sheep have diverged into two extant species -- Dall Sheep that occupy Alaska and northwestern Canada, and Bighorn Sheep that range from southern Canada to Mexico. However, the status of these species is questionable given that hybridization has occurred between them in their recent evolutionary history.
Bighorn Sheep are named for the large, curved horns borne by the males, or rams. Females, or ewes, also have horns, but they are short with only a slight curvature. They range in color from light brown to grayish or dark, chocolate brown, with a white rump and lining on the back of all four legs. Rocky Mountains Bighorn females weigh up to 200 lb (90 kg), and males occasionally exceed 500 lb (230 kg). In contrast, Sierra Nevada Bighorn females weigh about 140 lb (60 kg) with males weighing around 200 lb (90 kg). Males' horns can weigh up to 30 lb (14 kg), as much as the rest of the bones in the male's body.[12]

Bighorn sheep graze on grasses and browse shrubs, particularly in fall and winter, and seek minerals at natural salt licks. Bighorns are well adapted to climbing steep terrain where they seek cover from predators such as coyotes, eagles, and cougars. They live in large herds, but do not have the strict dominance hierarchy of the mouflon: that is, they do not automatically follow a single leader ram, unlike the Asiatic ancestors of the domestic sheep.

Prior to the mating season or "rut", the rams attempt to establish a dominance hierarchy that determines access to ewes for mating. It is during the prerut period that most of the characteristic horn clashing occurs between rams, although this behavior may occur to a limited extent throughout the year.[13] Ram's horns can frequently exhibit damage from repeated clashes. Bighorn ewes exhibit a six-month gestation. In temperate climates, the peak of the rut occurs in November with one, or rarely two, lambs being born in May. The lambs are then weaned when they reach 4-6 months.

Bighorn Sheep are highly susceptible to certain diseases carried by domestic sheep such as scabies and pneumonia; additional mortality occurs as a result of accidents involving rock fall or falling off cliffs (a hazard of living in steep, rugged terrain).
Bighorn Sheep were amongst the most admired animals of the Apsaalooka, or Crow, people, and what is today called the Bighorn Mountain Range was central to the Apsaalooka tribal lands. In the Bighorn Canyon National Recreation Area book, storyteller Old Coyote describes a legend related to the Bighorn Sheep. A man possessed by evil spirits attempts to kill his heir by pushing the young man over a cliff, but the victim is saved by getting caught in trees. Rescued by Bighorn sheep, the man takes the name of their leader, Big Metal. The other sheep grant him power, wisdom, sharp eyes, sure footedness, keen ears, great strength, and a strong heart. Big Metal returns to his people with the message that the Apsaalooka people will survive only so long as the river winding out of the mountains is known as the Bighorn River.[15]

Bighorn Sheep are hunted for their meat and horns, which are used in ceremonies, as food, and as hunting trophies. They also serve as a source of eco-tourism, as tourists come to see the famed Bighorn Sheep in their native habitat.[citation needed]

The Rocky Mountain Bighorn Sheep is the provincial mammal of Alberta and the state animal of Colorado and as such is incorporated into the symbol for the Colorado Division of Wildlife.[16]

Bighorn Sheep were once known by the scientific identification argali or argalia due to assumption that they were the same animal as the Asiatic Argali (Ovis ammon).[17] Lewis and Clark recorded numerous sightings of Ovis canadensis in the journals of their exploration--sometimes using the name Argalia. In addition, they recorded the use of bighorn sheep by the Shoshone in making bows.[18] William Clark's Track Map produced after the expedition in 1814 indicates a tributary of the Yellowstone River named Argalia Creek and a tributary of the Missouri River named Argalia River, both in what is today Montana. Neither of these tributaries retained these names however. The Bighorn River another tributary of the Yellowstone, and its tributary stream the Little Bighorn River indicated on Clark's map did retain their names, the latter being the namesake of the Battle of the Little Bighorn