Tuesday 21 May
Bighorn sheep (Ovis canadensis)
What’s the World’s Favourite Species?Find out here.
Bighorn sheep fact file
- Find out more
- Print factsheet
Bighorn sheep description
The bighorn sheep is named for its massive, spiral horns, which in the male can reach lengths of over a metre (5) and weigh up to 14 kilograms, equalling the weight of the entire skeleton (2). The coat of this species is hairy rather than woolly, and coloured glossy brown in the summer, becoming paler in the winter (2). The hooves are black, the tail is short, and the rump has a conspicuous pale patch (6). The female’s horns, though large compared to some species of sheep, are much smaller than the male’s, and less curved (2). There is some debate regarding the taxonomy of the bighorn sheep, with variable numbers of subspecies recognised by different authorities. The most recent research indicates that there may be three distinct subspecies, which occupy separate geographical areas: the Rocky Mountain bighorn sheep (Ovis canadensis canadensis); the Sierra Nevada bighorn sheep (Ovis canadensis sierrae), and the desert bighorn sheep (Ovis canadensis nelsoni) (7) (8)
- Also known as
- Mountain sheep.
- Mouflon D'Amérique, Mouflon Du Canada, Mouflon Pachycère.
- Borrego Cimarrón, Carnero Del Canadá, Carnero Salvaje. Top
- Grand Slam Club/Ovis:
- A herb with broad leaves that grows alongside grasses in a field, prairie or meadow.
- The state of being pregnant; the period from conception to birth.
- A population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.
- IUCN Red List (September, 2009)
- Burnie, D. (2001) Animal. Dorling Kindersley, London.
- Macdonald, D.W. (2006) The Encyclopedia of Mammals. Oxford University Press, Oxford.
- CITES (September, 2009)
- Nowak, R.M. (1991) Walker's Mammals of the World. The Johns Hopkins University Press, Baltimore and London.
- Schmidly, D.J. and Davis, W.B. (2004) The Mammals of Texas. University of Texas Press, Austin.
- Wehausen, J.D. and Ramey, R.R. (2000) Cranial morphometric and evolutionary relationships in the northern range of Ovis canadensis. Journal of Mammology, 81: 145 - 161.
- Wehausen, J.D., Bleich, V.C. and Ramey, R.R. (2005) Correct nomenclature for Sierra Nevada Bighorn Sheep. California Fish and Game, 91: 216 - 218.
- Grand Slam Club/Ovis (September, 2009)
- view the contents of, and Material on, the website;
- download and retain copies of the Material on their personal systems in digital form in low resolution for their own personal use;
- teachers, lecturers and students may incorporate the Material in their educational material (including, but not limited to, their lesson plans, presentations, worksheets and projects) in hard copy and digital format for use within a registered educational establishment, provided that the integrity of the Material is maintained and that copyright ownership and authorship is appropriately acknowledged by the End User.
Bighorn sheep biology
Well adapted to its rocky environment, the agility and keen eyesight of the bighorn sheep help it to detect and evade predators, and when threatened, it will bound away over rocks, climbing nearly vertical rock faces where its pursuer can rarely follow (2) (5). This species is generally active during the cooler parts of the day, resting in a shallow, scraped-out depression during hotter periods (5) (6). While nocturnal activity has also been recorded (5), this species typically spends the night huddled in groups on rocky slopes that offer a wide view of the surroundings to guard against predation (6). During the day, the herds, which may number more than 100 individuals, forage over home ranges spanning several kilometres (5). The diet varies according to location, but mainly comprises grasses, along with forbs, and the leaves, shoots and twigs of available shrubs and trees (1). Outside the breeding season, there are two distinct types of herds, which comprise either sexually mature males or females and mixed-sex, immature offspring (1) (5). Both herds make seasonal movements, which exceptionally have been known to cover 48 kilometres, dispersing into more expansive upland regions in the summer, and concentrating in sheltered valleys in the winter (5).
The bighorn sheep breeds during the autumn and early winter, with births taking place in the spring. During the mating period or “rut”, males take part in spectacular battles for dominance and the chance to mate. After pushing and shoving one another, the males back away, before rearing up on the hind legs and lunging forwards and down, bringing the horns together with tremendous force (2) (5). These contests may last for hours until one of the rams give in (2). After a gestation period of around 174 days, the female usually gives birth to a single young (5), though litters of two and three offspring have also been recorded (2). After the first few weeks, the young spend little time around the mother, and instead form groups with other juveniles, returning only to suckle (5). Weaning takes place at four to six months old, after which the young join the mother’s herd. Females often remain in this herd for life, whereas males depart at around two to four years old and join a herd of rams. A dominance hierarchy exists in both types of herd, which is defined mostly by age, as well as by horn size amongst the rams (5). Within the herds, the younger members are taught seasonal pathways and suitable habitats by the adults (2). Females usually mate and produce offspring at around 18 months old, whereas males do not usually breed until over 3 years old (1), when developed enough to successfully compete for a mate (5). On average, the bighorn sheep lives for around 9 years, with males rarely exceeding 12 years, and females 15 years (5).Top
Bighorn sheep range
The bighorn sheep ranges from south-west Canada, south through the western and central USA to northern Mexico (2).Top
Bighorn sheep habitatTop
Bighorn sheep statusTop
Bighorn sheep threats
During the late 19th and early 20th century, bighorn sheep numbers suffered a dramatic decline as result of overhunting and competition with domestic sheep and goats. This was further compounded by outbreaks of disease, such as mange and pneumonia, which were generally transferred from domestic livestock. Today, thanks to extensive conservation and management efforts the bighorn sheep has made a substantial recovery, and with a relatively large, stable total population, is no longer considered to be threatened. Nevertheless, the situation for some regional populations is much less favourable, as the small herd sizes are particularly vulnerable to extirpation. Without conservation action, the ongoing habitat degradation, poaching, and spread of disease affecting these populations could potentially lead to the loss of unique races of the bighorn sheep (1).Top
Bighorn sheep conservation
A significant proportion of the bighorn sheep’s total population can be found within the many Canadian and US protected areas that occur within its range. These areas provide a valuable refuge from hunting and habitat degradation, although poaching remains problematic. Outside the protected areas, populations are widely hunted, but generally well managed through well-enforced hunting laws, requiring permits and specifying annual quotas (1). Collaboration between hunters and conservationists has led to the formation of numerous conservation groups, which are working to ensure that the bighorn sheep remains abundant (9). Various programmes have been initiated such as habitat improvement and the translocation of bighorn sheep to new areas, along with research into this species’ biology. Nevertheless, it is important that the small, declining herds that are found in some regions receive specific attention in order to prevent extirpation (1).
In Mexico, the bighorn sheep is listed on Appendix II of the Convention on International Trade in Endangered Species, which restricts all international trade in this species through the use of trade permits and export quotas. Nevertheless, populations in Mexico are seriously affected by poaching and a lack of protected areas. This situation may be changing, however, as private landowners, capitalising on the high prices that hunters are willing to pay to hunt wild sheep, are now investing funds into monitoring and management programmes for the bighorn sheep (1).Top
Find out more
To find out about conservation organisations working to protect the bighorn sheep visit:
AuthenticationThis information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact: firstname.lastname@example.orgTop
MyARKive offers the scrapbook feature to signed-up members, allowing you to organize your favourite ARKive images and videos and share them with friends.
Terms and Conditions of Use of Materials
Copyright in this website and materials contained on this website (Material) belongs to Wildscreen or its licensors.
Visitors to this website (End Users) are entitled to:
End Users shall not copy or otherwise extract, alter or manipulate Material other than as permitted in these Terms and Conditions of Use of Materials.
Additional use of flagged material
Green flagged material
Certain Material on this website (Licence 4 Material) displays a green flag next to the Material and is available for not-for-profit conservation or educational use. This material may be used by End Users, who are individuals or organisations that are in our opinion not-for-profit, for their not-for-profit conservation or not-for-profit educational purposes. Low resolution, watermarked images may be copied from this website by such End Users for such purposes. If you require high resolution or non-watermarked versions of the Material, please contact Wildscreen with details of your proposed use.
Creative commons material
Certain Material on this website has been licensed to Wildscreen under a Creative Commons Licence. These images are clearly marked with the Creative Commons buttons and may be used by End Users only in the way allowed by the specific Creative Commons Licence under which they have been submitted. Please see http://creativecommons.org for details.
Any other use
Please contact the copyright owners directly (copyright and contact details are shown for each media item) to negotiate terms and conditions for any use of Material other than those expressly permitted above. Please note that many of the contributors to ARKive are commercial operators and may request a fee for such use.
Save as permitted above, no person or organisation is permitted to incorporate any copyright material from this website into any other work or publication in any format (this includes but is not limited to: websites, Apps, CDs, DVDs, intranets, extranets, signage, digital communications or on printed materials for external or other distribution). Use of the Material for promotional, administrative or for-profit purposes is not permitted.