California Bighorn Sheep

Safari Club International (SCI) has added California Bighorn Sheep to its Grand Slam, after distinguishing it as a subspecies from the Rocky Mountain Sheep. The SCI minimum score is 150, making every ram in our area sure to make the book!

“As they came out, I started counting 1, 2, 3, 4, 5 — there were 10 rams all told. I can’t explain the anticipation as these sheep worked their way toward us. My ram scored green at 170, with 15½ inch bases and a horn length of 35 inches. In the group of 10 rams I saw earlier, there was at least 2 bigger rams than mine. Thanks for a great hunt.”

Dana, New York, USA

Bighorn sheep rams have large, heavy-set brown horns that curl back and down close to the head.
Ewes have thinner, shorter horns and male lambs have small stubs which in adult rams are known as lamb-tips. These Bighorn sheep are brown with a distinctive white rump. In BCTMO Conservation Club's guide territory, you are able to hunt both 3/4 curl and full curl Bighorn rams.
Two sub-species of Bighorn sheep are present in British Columbia:
California Bighorn Sheep (Ovis canadensis californiana) are found from south-central British Columbia to the east side of the Coast and Cascade Ranges and down into Northern California. Transplants now also place California Bighorns in northwestern Idaho and western North Dakota. Within BC, the California Bighorn is found in the Thompson Nicola, Cariboo and Okanagan regions, to where they are native, with estimates of 3000 Bighorn sheep in the province. This is the subspecies that is found in BCTMO Conservation Club's guide territory.
Rocky Mountains Bighorn (Ovis canadensis canadensis) are found in the Canadian Rockies of British Columbia and Alberta and south along the Rockies all the way to New Mexico.

While California Bighorns and Rocky Mountain Bighorns look similar, the first is lighter and California Bighorn rams have horns that flare outward more.
Bighorn sheep's horns grow year round, but grow slower in the winter. Bighorn rams develop annuli rings, black rings around the horns that indicate the slower period of growth during the winter. This allows an observer to determine the ram's age by counting the lines, however these lines are not as distinctive as those of other species of sheep such as the Dall sheep. For this reason, a harvestable California Bighorn ram is determined by the position of the horns. A full curl Bighorn ram's horns will cross an imaginary line between his nose and eye. A 3/4 curl Bighorn ram's horns have curled back in front of his eyes, but have not yet crossed this line between nostril and eye.
Ewes and rams both have horns but the ewe's are short, thinner at the base and do not curve around as much as the ram's. Horns grow from the base throughout the sheep's life. Ram's horns can be up to 51” around the curve with average sheep taken in our territory 28-38” and as thick as 15” around the base, averaging 14-17” in our territory. When the ram's horn reaches full curl, it starts to interfere with the ram's sight. The ram will rub the horns against rocks causing them to broom off.
Coat colour ranges from grey-brown to dark brown with a white nose patch, white on the legs and a large, distinctive white rump surrounding a short black tail. Previously the California bighorn wasn't differentiated from the larger Rocky Mountain Bighorn sheep in record keeping such as by Safari Club International. The SCI and other hunting organizations now recognize the California Bighorn sheep as a subspecies in its record book. This has benefited conservation of the California Bighorn as more interest is now shown to this subspecies by hunters meaning more conservation dollars and more projects to protect these animals. The California Bighorn was previously overlooked by many hunters due to its 20% smaller body size compared to Rocky Mountain Bighorns as well as shorter and smaller horns. California Bighorns also tend to be paler in the body.
Adult Bighorn rams are about 3' tall at the shoulder and usually weigh 200 to 300 lbs. Ewes are about 1/3 smaller than rams. Bighorn sheep have specially adapted hoofs to allow them to negotiate steep, rocky terrain, but not as efficiently as mountain goats. They are also efficient at climbing and jumping, leaping off ledges of up to 20 feet high. They are equally adept at ascent and descent.
California Bighorn sheep normally live 12 to 14 years, the oldest sheep ever recorded was 20 years old.

Bighorn sheep are specialized grazers and can survive on hard, dry and abrasive plants. Their bodies are designed to digest less luxuriant grass more slowly, therefore getting more nutrition. After the first snow, they will eat all available grasses.
California Bighorn sheep are usually found in rugged terrain, with little tree cover, areas of low-growing grasses and areas where the snow is less deep in the winter. This means Bighorn sheep are found in dry climates and on south and south-west orientated timbered mountains with rolling hills and grasslands. Elevation can range from 2000 to 8000 ft.
California Bighorn sheep winter range mostly consists of low-elevation grasslands where vegetation includes bunchgrass, Ponderosa pine, Douglas fir, fescue, bluegrass, and blue-bunch wheat-grass, which are key species on most winter ranges. However when sheep eat conifers such as Douglas fir, this suggests there is an absence or scarcity of more preferred food sources.
These Bighorn sheep move to their summer ranges in spring where they graze on plants like June grass, dwarf willow and half shrub pasture sage when they are in their most nutritious early growth stage. During the summer they eat grasses and sedge, herbs such as lupine, willows and other low shrubs.
Bighorn sheep migrate 25 to 40 miles between their winter and summer ranges. The lambing range is generally between their summer and winter ranges, in south-facing areas. Males and females occupy separate summer ranges.

Bighorn sheep migrated into North America over the Bering Land Bridge during the Paleolithic period. The Bighorn sheep's ancestors were the first domesticated sheep in Eurasia. But the North American wild Bighorn sheep have never been domesticated.
California Bighorn sheep are a social species where both ewes and rams live in groups 5 to 20 or more. Ewe and ram groups live separately most of the time, except during the mating season. Seasonal range locations are used for generations and learned by following the older and experienced sheep, in ewe groups, there is a lead ewe. In Bighorn ram groups there is a clear social structure and dominance hierarchy where the sheep with the biggest horns is often in charge. Bighorn rams of similar horn size fight for control of the entire female herd and the breeding privileges. Facing each other from a distance of 30 ft, they run towards each other at speeds of 20mph with heads lowered, rearing up and crashing their horns together. Bighorn rams have adapted double-layered skulls which absorbs the impact of the collisions and means serious injuries are rare. However, some studies have shown rams with the biggest horns appear to have the shortest lifespan. These fights are always a dramatic sight to witness, the snow capped peaks of late fall echoing with the sound of the fight.
California Bighorn sheep mate between October and mid December with the sheep in our territory mating in November. Ewes are pregnant for 170 to 180 days and give birth in April to June to lambs that weighs around 6 to 11 lbs. Twins and singletons are of equal frequency. During the summer, lambs' growth is fast and by the fall they weigh 65lbs. They are weaned by October. Most ewes breed for the first time at 2 years old. Physiologically, Bighorn rams are able to breed at the same age but they usually have gain a higher rank, meaning they may be 7 or 8 years old before getting a chance to mate.
50% of lambs and 20% of yearlings die from starvation, predation (particularly from cougar and coyote), accident and disease each year. Bighorn sheep frequently contract pneumonia from domestic sheep and goat disease. While these are relatively harmless for domestic sheep, they can be fatal to California Bighorn sheep, mostly lambs and older sheep. At BCTMO Conservation Club, we carefully record the location, age and sex of all sheep that we see. This allows us to build up detailed records of the sheep herds in our territory to assess annual herd recruitment and assess if lamb death is more likely a cause of predation or disease. From this, we shape our conservation management practices to help maintain our Bighorn sheep populations at a sustainable herd size.
The Bighorn rut is from October to December, with the sheep in our territory mostly mating in November.

As a result of over-hunting, disease and parasites contracted from domestic sheep and grazing competition with domestic cattle, Bighorn sheep populations were dangerously low in the early 1900s. Hunting was closed or very restricted until the 1950s, allowing the Bighorn sheep populations to increase. However, winter and summer ranges were still in poor condition. In the 1970s, government agencies and hunting groups initiated the first significant habitat management program.
Today, many winter and summer ranges are reserved and managed for the benefit of Bighorn sheep. However, the two subspecies are still considered at risk. A major concern is the fragmentation of Bighorn habitat and the preservation of migration corridors. Bighorn sheep winter ranges still have to be protected from livestock grazing practices and burning practices. Through working with local loggers and other resource users, BCTMO Conservation Club works to ensure human impact on California Bighorn sheep is minimized.