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COMMON NAME |
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Desert Bighorn Sheep
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SCIENTIFIC NAME: |
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Ovis canadensis
nelsoni |
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CLASSIFICATION: |
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Mammal |
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SIZE: |
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Length: 5 feet
Height: 2 ½ – 3 ¼ (at shoulders)
Weight: Male 140 – 180 pounds
Female 90 – 150 pounds |
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DESCRIPTION: |
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The most
conspicuous feature of the desert bighorn sheep is the large
brown horns that continue to grow. Both rams (males) and ewes
(females) have horns, though the horns of rams are much bigger
and more curved. Each horn is in a “C” shape known as a “curl”.
The horns are permanent and consist of a sheath of keratin (a
hard protein found in fingernails and hair) covering a boney
core. |
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LIFE SPAN : |
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6 – 8 years
A ram in the River Mountains lived at least 18 years
A ewe in the Last Chance Range lived at least 19 years |
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HABITAT: |
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Typical desert
bighorn terrain is rough, rocky and steep, broken up by canyons
and washes. This type of terrain affords them the advantage in
coping with predation. Desert bighorns live in regions of the
state marked by hot summers and little annual precipitation.
Bighorn sheep require access to freestanding water during summer
months, and in drought conditions they may water throughout the
year. |
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RANGE: |
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Desert
bighorns are located in mountain ranges throughout the
southwest. Besides the southern region of Nevada, populations
exist in Arizona, southeast California, Colorado, New Mexico,
Utah, Texas and Mexico. |
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NATURAL HISTORY: |
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The number of
desert bighorn sheep in North America in pristine times is
unknown, but most likely in the tens of thousands. By 1960, the
overall population in the United States had dwindled to 6,700 –
8,100. These declines were attributed to excessive hunting,
competition and diseases from domestic livestock, particularly
domestic sheep; usurpation of watering areas and critical range
by human activities; and human-induced habitat changes. Since
1960, after the adoption of conservation measures, the
population trends have been upwards. In 1993 the population
estimate was 18,956 – 19, 040. |
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FOOD HABITS: |
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Desert Bighorns
are herbivores. Their diet varies with habitat and seasons, but
they prefer to eat grasses, forbs, when available, and shrubs.
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BREEDING: |
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The breeding
season or rut generally extends from July through September. In
each band of rams there is a dominance order. This order is
determined in several ways which could include the rams clashing
heads in a fight. The dominant males do most of the breeding.
Bighorn sheep have an approximate 6 month gestation period with
most ewes giving birth to one lamb per year. |
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STATUS: |
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NDOW Game
Mammal |
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REASON FOR STATUS: |
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MANAGEMENT & CONSERVATION:
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Management
strategies have been implemented to maintain or enhance desert
bighorn populations. Transplants have been highly successful in
some areas. Aggressive programs to stop poaching have been
effective, and hunting is strictly regulated. Wildlife agencies
and conservation organizations are involved in habitat
improvement projects that include building water developments. |
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FUN FACTS: |
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Water
developments have been and continue to be constructed in
habitats deemed deficient in water. Although rams may go 3 days
without water, ewes and lambs come to water holes almost daily
during the hot, dry summer months.
During the rutting season in July through September, dominance among
rams is established in contests in which two rams may clash
horns. It has been estimated rams may meet head-on at a combined
speed of approximately 30 mph. |
