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Bighorn Sheep

Genus: Ovis
Species: canadensis

bighorn sheep



By 1900, encroachment from human settlers diminished the population to several thousand. Bighorn sheep have made a comeback thanks to a conservation movement supported by President Theodore Roosevelt, reintroductions, national parks, and managed hunting. Unfortunately, some subspecies, such as Ovis canadensis auduboni of the Black Hills, were driven into extinction.



Today and in the past, the efforts of conservation groups have also served to increase awareness and "petition" to place certain sub-species like the Sierra Nevada bighorn sheep on the Endangered Species List.


Big Horn Ram


Its compact body is muscular, with chocolate brown fur trimmed in white on the muzzle, rump and belly. Most weigh 160-250 pounds, but rams may weigh over 350 pounds and stand around 40 inches at the shoulder.


The latest science shows that "bighorn sheep" is one species, with 3 living subspecies:

  1. Rocky Mountain Bighorn Sheep (Ovis canadensis canadensis)
  2. Sierra Nevada Bighorn Sheep (Ovis canadensis sierrae), formerly California Bighorn Sheep
  3. Desert Bighorn Sheep (Ovis canadensis nelsoni)


Horns & Hooves: Large, curved horns, borne by the males, or rams, can weigh up to 30 lb (14 kg) - as much as the rest of the bones in the male's body. Older rams have massive horns that can grow over 3 feet long with more than one foot in circumference at the base.




Habitat and Range: Bighorn sheep live in the western mountainous regions of North America, ranging from southern Canada to Mexico.

Their steep mountainous habitat, with ledges sometimes only 2 inches wide, provides cover from predators such as coyotes, golden eagles, mountain lions, bears, and Canada lynx. The sheep are important food sources for these large predators.



bighorn sheep


Males depart their mother's group around 2 to 4 years of age and join a group of rams. This is sometimes a tough time of wandering until the young rams find a male group and they will sometimes take up with other species out of loneliness.



Diet: As ruminants, grass-eating bighorn sheep have a complex four-part stomach that enables them to eat large portions rapidly before retreating to cliffs or ledges where they can thoroughly re-chew and digest their food, safe from predators. Then bacteria takes over, breaking down plant fibers for digestion. The sheep also absorb moisture during this digestive process, enabling them to go for long periods without water.


Lifespan: Longevity depends on population status. In declining or stable populations, most sheep live over 10 years. Even in areas where no hunting occurs, females rarely make it past 15 and males rarely live beyond 12. Juvenile mortality is variable and can be quite high, ranging from 5 to 30%. Sheep between 2 and 6 years old have low mortality.



Mating competition involves two rams running toward one another, at speeds around 40 mph, and clashing their curled horns, which produces a sound that can be heard a mile away. Most of the characteristic horn clashing between rams occurs during the pre-rut period, although this behavior may occur to a limited extent throughout the year.


Featured Video: Peak to Peak

Researcher Jack Hogg discusses bighorn sheep behavior and how future generations could be affected by climate change.

Peak to Peak from Conservation Media on Vimeo.


  • Predators
    Mountain lions, coyotes, wolves and bears will all kill mountain sheep if given the opportunity, but chasing the sheep in the cliffs is rarely successful.

  • Disease
    Disease usually takes a far higher toll among bighorns than predators.

  • Accidents
    As sure-footed as they are, bighorn sheep sometimes slip and fall from the cliffs or are struck by falling rocks.

  • Poaching of large, trophy males.


National Wildlife Magazine Articles

Battle for Bighorns

Counting Sheep
Conservation efforts seem to be paying off for bighorns in the West

Giving Sheep a Personality Test
Scientists discover distinct temperaments in Rocky Mountain bighorns


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