Bighorn Sheep

Bighorn Sheep

Kingdom
Phylum
Subphylum
Class
Order
Family
Subfamily
Genus
SPECIES
Ovis canadensis
Population size
70,000
Life Span
9-14 years
Top speed
30
19
km/hmph
km/h mph 
Weight
34-143
74.8-314.6
kglbs
kg lbs 
Height
76-104
29.9-40.9
cminch
cm inch 
Length
140-200
55.1-78.7
cminch
cm inch 

The Bighorn sheep (Ovis canadensis) is a species of sheep native to North America. Sheep originally crossed to North America 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.

Di

Diurnal

He

Herbivore

Fo

Folivore

Gr

Graminivore

Te

Terrestrial

Cu

Cursorial

Al

Altricial

Co

Congregatory

Vi

Viviparous

Gr

Grazing

Br

Browsing

Po

Polygyny

So

Social

He

Herding

Do

Dominance hierarchy

Mi

Migrating

B

starts with

U.

U.S. States Animals
(collection)

Be

Best Horns
(collection)

Appearance

Bighorn sheep are named for the large, curved horns borne by the rams (males). A pair of horns might weigh up to 14 kg (30 lb), while the sheep typically weigh up to 143 kg (315 lb). Ewes (females) also have horns, but they are shorter with less curvature. They range in color from light brown to grayish or dark, chocolate brown, with a white rump and lining on the backs of all four legs. Male bighorn sheep have large horn cores, enlarged cornual and frontal sinuses, and internal bony septa. These adaptations serve to protect the brain by absorbing the impact of clashes. Bighorn sheep have preorbital glands on the anterior corner of each eye, inguinal glands in the groin, and pedal glands on each foot. Secretions from these glands may support dominance behaviors.

Distribution

Geography

Bighorn sheep live in North America in the western mountainous areas, from southern Canada to Mexico. Their habitat consists of grassy mountain slopes, alpine meadows, and foothill country near rocky, rugged cliffs and bluffs. Bighorn sheep need drier slopes where the snowfall is no more than about sixty inches annually, as they cannot walk in deep snow to feed.

Bighorn Sheep habitat map

Climate zones

Bighorn Sheep habitat map
Bighorn Sheep

Habits and Lifestyle

Bighorn sheep are diurnal. They are very social creatures, sometimes forming herds of up to 100, although more common are small groups of 8 to 10. Mature males keep away from young and females in separate flocks for most of the year. Young females remain with their mother's group, which is led by an older ewe. These sheep are very alert and their excellent eyesight enables them to accurately judge distances when jumping and finding footholds. In the autumn, the rams compete for ewes with butting contests, charging at each other faster than 20 miles per hour, their foreheads crashing together with a loud crack that one can hear a mile away. Such battles may go on for as long as 24 hours.

Seasonal behavior

Diet and Nutrition

The diet of Bighorn sheep varies according to the season. They are herbivorous (folivorous, graminivorous) animals and in summer they eat grasses or sedges. In winter they eat plants that are more woody, like shrubs, and willow. They also seek minerals at natural salt licks.

Mating Habits

MATING BEHAVIOR
REPRODUCTION SEASON
November-December
PREGNANCY DURATION
150-180 days
BABY CARRYING
1-2 lambs
INDEPENDENT AGE
4-6 months
FEMALE NAME
ewe, dam
MALE NAME
buck, ram
BABY NAME
lamb, lambkin

The breeding season is from November to December, and the young are born in the spring. Ewes will mate with several rams. After a gestation period of 150-180 days, one, and very occasionally two young are born. After only a week, lambs can follow their mothers confidently over the rocky terrain. Several few weeks after birth, lambs form groups of their own, going to their mothers only to drink milk now and again. By 4 to 6 months they are completely weaned. Females in captivity have been mated at 10 to 11 months, but they usually do not breed in the wild until in their second or third year. Due to fierce competition for females between males, and a hierarchy that is based on age and size (horn size as well), males are usually 7 years old before they mate. If dominant rams are killed, younger males in their group will mate sooner.

Population

Population threats

Unregulated or illegal hunting is the main threat, as well as competition from livestock, introduced diseases, and ongoing human encroachment where they live. Accidental deaths sometimes occur from falls, fighting, highway traffic, and avalanches. Predators include coyotes, wolves, mountain lions, and bobcats.

Population number

It is thought that at the beginning of the 19th century, Bighorns in North America numbered up to two million, but there are about only 70,000 today, including 15,700 sheep in Canada, 42,700 in the U.S., and 4,500 in Mexico. Overall, Bighorn sheep are currently classified as Least Concern (LC) on the IUCN Red List, and their numbers today remain stable.

Ecological niche

These sheep are important predators of shrubs and grasses in their native landscapes. Bighorn sheep are also important prey for large predators.

Fun Facts for Kids

  • The female is called a "ewe" and the male is called a "ram".
  • Desert bighorn do not need water to drink during winter when green vegetation is present. During summer they drink at waterholes at least once every three days.
  • The hooves of these sheep have a strong grip when they are walking on rocky surfaces.
  • In winter, Bighorns move to areas where there is less snow, as they find it hard to walk in the snow.
  • Desert bighorn sheep use two unusual techniques for cooling their bodies during hot summers: panting and perspiring. Only during rainy seasons do desert bighorn exhibit the usual behavior of their species.
  • Bighorn sheep have the unique ability to be able to jump 6 meters from ledge to ledge.

References

1. Bighorn Sheep Wikipedia article - https://en.wikipedia.org/wiki/Bighorn_sheep
2. Bighorn Sheep on The IUCN Red List site - http://www.iucnredlist.org/details/15735/0

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