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Bighorn Sheep (Ovis canadensis) Fact Sheet: Physical Characteristics

Bighorn Sheep (Ovis canadensis)

Physical Characteristics

Body measurements

AttributeMalesFemales
Weight 68-90 kg (150-200 lb) 45-57 kg (100-125 lb)
Length 127-157 cm (50-62 in)
Shoulder height 81-101 cm (32-40 in)

General Appearance

Horns

  • Both sexes have horns that grow throughout their lives:
    • Male horns are massive, curling and diverging.
    • Female horns are smaller, thin and curved.
  • Horns consist of a bony core with a permanent sheath of keratin. Sheaths grow from the base
  • Mountain bighorns have by far the biggest horns. Longest horn length recorded measured 52 inches with a basal circumference of 18 inches (horn tips are often broken, splintered or broomed)
  • Clark (1940) reports a weight of 44 lbs (upper skull and horn) for a Canadian Rocky ram
  • Growth rings (annuli) are formed in the fall and are associated with hormone and diet changes.
    • First visible annulus is 2.5 years.
    • Fourth year is the first heavy, dark ring.

Pelage

  • Smooth outer coat of brittle guard hairs and short, gray, crimped fleece underfur
  • Fur is a pale brown, paler in appearance than other bighorn sheep
  • The summer coat is a rich, glossy brown but can fade by late winter
  • Female fur is often lighter than the males
  • Whitish patch on rump
  • Molting usually occurs in June and July. Molting progresses from posterior region with chest the last to shed.

Sexual Dimorphism

Horns

  • Male horns become a full curl by 7-8 years of age and spread of up to 33 inches (up to 30-40 lbs.)
  • Female horns are smaller than the rams and never exceed half a curl.

Other Physical and Physiological Characteristics

  • Compact and muscular body
  • Climbing, cloven hooves providing amazing jumping ability
  • Acute eyesight

Male Bighorn Sheep

Bighorned Sheep

As an adult, a male bighorn sheep's horns are nearly 3 feet across.

Image credit: © San Diego Zoo Global. All rights reserved.

Adapted for Climbing Rocks

hoof of a bighorned sheep

Image credit: © San Diego Zoo Global. All rights reserved.

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