The bighorn's body is compact and muscular; the muzzle, narrow
and pointed; the ears, short and pointed; the tail, very short.
The fur is deerlike and usually a shade of brown with whitish rump
patches. The fur is smooth and composed of an outer coat of brittle
guard hairs and short, gray, crimped fleece underfur. The summer
coat is a rich, glossy brown but it becomes quite faded by late
The male sheep is called a ram and can be recognized by his
massive brown horns. The horns curl back over the ears, down, and
up past the cheeks. By the time a ram reaches seven or eight years
of age, he can have a set of horns with a full curl and a spread
of up to 33 inches. Ewes, the females, are smaller than the rams
and have shorter, smaller horns that never exceed half a curl.
The desert subspecies, Ovis canadensis nelsoni, is somewhat
smaller and has flatter, wider-spreading horns.
Bighorn Geography Range
Bighorn Sheep Vital Stats
The natural range of Ovis canadensis was formerly
in the Rocky Mountains from southern Canada to Colorado, but is
now reduced to areas where small bands are protected by inaccessible
habitat or by refuges. The desert subspecies (Ovis canadensis nelsoni)
ranges from Nevada and California to west Texas and south into Mexico.
Another rare group inhabits the Sierra Nevada Mountains of California.
||Length with Tail:
||No. of Young:
||Bighorns can live 10 to 15 years
||mainly grasses, sedges and forbs
Bighorn Sheep - Curious Facts
- Known for head-to-head combat between males.
- Combat between rams has been observed to last for longer
than 24 hours.
- Horn size is a symbol of rank. Male horns can weigh as much
as 30 lbs.
- Desert bighorn do not require drinking water in winter when
green vegetation is available. During the summer months they visit
waterholes at least every three days.
- Bighorns have a complex 9-stage digestive process that allows
them to maximize removal of nutrients from food of marginal quality.
Desert bighorn are comprised by some accounts of four
subspecies. They live in dry, desert mountain ranges and foothills,
near rocky cliffs, in an environment that is almost waterless and
relatively barren of vegetation. In the winter they range farther
from their meager water sources to browse on vegetation in full
leaf. As summer approaches, they move closer to remaining water
supplies and reduce their own water output by resting during the
day in caves or under rocky overhangs.
One of the six species of the genus Ovis, Dall Sheep
(O. dalli), are often seen high on mountains of northwestern Canada
and Alaska. Dall sheep are smaller than bighorn, weighing only about
150 pounds maximum, and vary in color from white to almost black.
During the rut, bighorn rams will snort loudly. The lambs bleat,
and the ewes respond with a guttural "ba." They also utter
throaty rumbles or "blow" in fright.
Bighorn have extremely acute eyesight, which aids in jumping and
gaining narrow mountain footholds. They often watch other animals
moving at distances of up to a mile away.
The bighorn's tail is very short.
The ears are short and pointed.
The bighorn's muzzle is narrow and pointed.Bighorn sheep tracts
The cloven hooves are sharp-edged, elastic, and concave. They are
double-lobed, 3-3.5 inches long with foreprints slightly larger
than hindprints -- similar to deer prints but less splayed.
Bighorn sheep are gregarious, sometimes forming herds of
over 100 individuals, but small groups of 8-10 are more common.
Mature males usually stay apart from females and young for most
of the year in separate bachelor herds. They migrate seasonally,
using larger upland areas in the summer and concentrating in sheltered
valleys during the winter.
Males do not defend territories but rather engage in battles
over mating access to a particular female. Age as well as horn size
determines male dominance status. Although not as well built for
climbing as mountain goats, bighorn sheep zigzag up and down cliff
faces with amazing ease. They use ledges only two inches wide for
footholds, and bounce from ledge to ledge over spans as wide as
20 feet. They can move over level ground at 30 miles per hour and
scramble up mountain slopes at 15 m.p.h. They also swim freely,
despite their massive bulk and the weight of their horns.
Bighorns are generally active during the day, feeding morning,
noon and evening, then lying down to chew their cud. They retire
to their bedding areas for the night, which may be used for many
Desert bighorns utilize two mechanisms for cooling -- perspiring,
and also panting, which is a fairly uncommon adaptation for desert
animals. When the summer rains finally arrive, they resume the more
common behavior of their species.
Bighorn inhabit alpine meadows, grassy mountain slopes
and foothill country near rugged, rocky cliffs and bluffs, allowing
for quick escape. In winter, bighorn prefer slopes 2,500-5,000 feet
where annual snowfall is less than 60 inches a year, because they
cannot paw through deep snow to feed. Their summer range is between
6,000-8,500 feet in elevation.
Bighorn are primarily grazers, consuming grasses,
sedges, and forbs, but will eat young twigs, leaves, and shoots
when preferred food is scarce (especially in winter). Desert bighorns
(O. c. nelsoni) eat a variety of desert plants and get most of their
moisture from the vegetation, although they still visit water holes
When summer temperatures become extreme and water sources dry
up completely, desert bighorns rest most of the daylight hours and
feed at night. During this season, they rely on certain desert plants
for both food and moisture. They use their hooves and horns to remove
spines from cacti, then eat the juicy insides. They are fond of
the tender shoots of prickly pear and cholla, and the flowers of
succulents like agave and squawgrass.
Rutting season is in the autumn
and early winter, and births take place in the Bighorn sheep spring,
though mating can last from July to December. Gestation lasts from
150-180 days. One or two lambs are born from late February to May.
Within a few weeks of birth, lambs form bands of their own, seeking
out their mothers only to suckle occasionally. They are completely
weaned by 4-6 months of age.
In the desert, only about one-third of the lambs will survive
their first summer. A lamb born late in the season stands little
chance of survival, since temperatures reach over 100 degrees F
in May and often reach 120 F by June. Recent studies of high lamb
death rates focus on viruses possibly introduced by domestic livestock,
to which the native bighorn have little or no immunity.
Female bighorn usually do not breed until their second or third
year in the wild. Due to competition, males do not usually mate
until they are 7 years old. Most sheep live over ten years, with
a maximum of 20 years.
Ewes are protective of their young for many months. Yearlings,
often abandoned while the ewe is giving birth to her next lamb,
may be seen again with the ewe and lamb late in the spring. Bighorn
find safety in numbers and are ever watchful for predators such
as coyotes and mountain lions.
Threatened with eventual extinction, bighorn numbers
are only one-tenth the population that existed when Europeans first
began exploiting the Rockies. The subspecies Ovis canadensis auduboni
of the Black Hills and adjacent areas has already become extinct.
Hunting has been prohibited or controlled since the early 1900s,
but much illegal poaching still occurs.
In March, 1998, the Peninsular bighorn sheep was listed as endangered
by the U.S. Fish and Wildlife Service. Today, bighorn still range
into Baja California, but their numbers have dwindled to less than
three percent of the estimated 1.5 million of the early 1800s. In
1979 bighorn between Mt. San Jacinto and the Mexican border were
estimated to number 1,180; in 1996 that number had plummeted to
Recent genetic evidence indicates the Sierra Nevada bighorn
is a unique form of bighorn found only in the Sierra Nevada. Sierra
Nevada bighorn are rarer than the Florida panther, and rarer than
the California condor. They are clearly one of the most endangered
mammals of North America. In 1986 these sheep were reintroduced
to the Mono Basin from a population further to the south. Now the
population in Lee Vining Canyon is the primary hope for the future
of Sierra Nevada bighorn.
Human activities are responsible for the bighorn's
decline. Grazing, mining, depletion of water holes, homesteading
and use as camp meat spelled disaster for the bighorn. In the desert,
off-road vehicles, trespassing cattle, poaching in the 1960s and
early '70s, drought, disease and mountain lion predation have worked
together to push this population to the edge of extinction.