Desert Bighorn Sheep, Ovis canadensis
2002

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Bighorn Sheep


TAXONOMY & NOMENCLATURE
(McKenna, 1997)(Hall, 1981)(Valdez, 1999) (USFWS, 2000)(Young & Manville, 1960)(Ramey & Wehausen, 1993) (Shackleton, 1985) (Geist, 1971)(Boyce et al, 1999)


Describer (Date): Shaw (1804). The Canadian Sheep. Plate 610, the description and the index in Naturalist’s miscellany (by G. Shaw and E. Nodder), Vol 15. Nodder and Co., London

Kingdom: Animalia
    Phylum: Chordata
        Class: Mammalia
             Order: Artiodactyla* (Even-toed hoofed animals: includes pigs, sheep goats, cattle, deer)
                Suborder: Ruminantia (chevrotain, mouse deer, pronghorn, deer, giraffes, okapi, antelopes, goats,
                 sheep, ibexes, turs, markhors)
                    Family: Bovidae (buffalo, cattle, sheep, goats)
                         Sub-Family: Caprinae (goats, sheep)
                                Tribe: Caprini
                                    Genus: Ovis (Sheep, mouflons, urial, argali, bighorn, thin horns snow sheep, Dall's sheep)
                                         Species: Ovis ammon (Argali)
                                         Species: Ovis aries (Mouflon)
                                         Species: Ovis canadensis (American bighorn)
                                             Subspecies: Ovis c. auduboni - EXTINCT
                                             Subspecies: Ovis c. canadensis (Rocky mountain bighorn)
                                             Subspecies: Ovis c. californiana (California bighorn)
                                             Subspecies: Ovis c. cremnobates (Peninsular bighorn) - DESERT POPULATION
                                             Subspecies: Ovis c. mexicana (Mexicana bighorn) - DESERT POPULATION
                                             Subspecies: Ovis c. nelsoni (Nelson bighorn) - DESERT POPULATION
                                             Subspecies: Ovis c. weemsi (Weems bighorn) - DESERT POPULATION
                                       Species: Ovis dalli (Dall sheep)
                                       Species: Ovis nivicola (Siberian bighorn)
                                       Species: Ovis vignei (Urial)

*New anatomical and DNA evidence on the relationship between Artiodactyla (even-toed ungulates) and Cetacea (whales and dolphins) recently led to a merging of the two orders into a new group, Cetartiodactyla (Montgelard, 1997; reviewed in Kulemzina, 2009). As of October 2012, experts had not agreed on whether to define Cetartiodactyla as an official taxonomic order that would replace Artiodactyla and Cetacea. Some continue to list sheep in the order Artiodactyla (Franklin, 2011) or use the term Cetartiodactyla without defining it as an order (IUCN, 2008).

Taxonomy

Common Names Phylogeny

DISTRIBUTION & HABITAT
( Hall, 1981) (Hansen, 1980) (Risenhoover & Bailey,1985) (Shackleton, 1997)
(Ostermann et al,2001)(USFWS,2000) (USGS website, 2002)

Historical Distribution:  (Cowan's 1940 taxonomy). Records indicate at least 97 populations of desert bighorn occurred in California at one point.

Distribution map

Map: From Hall’s The Mammals of North America, Volume II, 1981. Based on Cowan

Ovis canadensis

  1. O. c. auduboni
  2. O. c. californiana
  3. O. c. canadensis
  4. O. c. cremnobates
  5. O. c. mexicana
  6. O. c. nelsoni
  7. O. c. weemsi

Current Distribution:  (Shackleton, 1997). Today, 61 bighorn populations remain (Toweill & Geist, 1999). The Recovery Plan for Bighorn Sheep in the Peninsular Ranges, California (2000) indicates 8 ewe subpopulations in Riverside, Imperial, and San Diego counties from the San Jacinto Mountains to the Mexican border. Link to IUCN map.

Maps: From Shackleton’s Wild Sheep and Goats and their Relatives, IUCN/SSC Status Survey and Conservation Action Plan for the Caprinae, 1997

Distribution map
Ovis canadensis in the U.S.

Distribution map
Distribution of desert bighorn in Mexico
                                c. O.c. cremnobates
                                m. O.c. mexicana
                                w. O.c. weemsi
                                i. O.c. mexicana (introduced on Isla Tiburon)


Habitat

PHYSICAL CHARACTERISTICS
(Bighorn Institute website, 2002)

Sexual Dimorphism Horns Pelage Other Physical Characteristics

BEHAVIOR & ECOLOGY
(Hansen, 1980)(Shackleton,1985 USFWS, 2000)(Valdez, 1999)


Activity Cycle

        Daily Pattern
Social Group Play Aggression Communication

        Displays         Vocalization         Olfaction/Scent Marking Interspecies Interaction (Bighorn Institute website, 2002)(USFW, 2000)

DIET & FEEDING
(Bighorn Institute website, 2002)(Hanson,1980)(Turner, 1973)(Valdez, 1999)


REPRODUCTION & DEVELOPMENT
(Turner & Hansen, 1980)( Shackleton, 1984)( USFWS, 2000) (Thompson & Turner, 1982)

Courtship
Reproductive Rate Gestation: Generally accepted as 6 months (171 - 185 days)

Life Stages

        Birth

        Infants (<1 year of age)         Weaning: Lambs are weaned by 6 months of age.

        Juveniles (1-2 years of age):         Subadults (2-3 years of age):          Young adults (4-5 years of age):         Adults (>5 years of age): Mortality Longevity Many rams live 9-12 years and ewes may live 10-14 years.



POPULATION STATUS
(IUCN website, 2002) (USFWS, 2000)(Shackleton, 1997)(Rubin, 1998)
Conservation:
Threats to survival

MANAGED CARE
(Gildart,1999) (USFWS, 2000)
ISIS captive population

Important Web Resources:

USFWS Recovery Plan -- For bighorn sheep in the peninsular ranges of California
Bighorn Institute
Coachella Valley Multiple Habitat Species Conservation Plan
IUCN Red List: Ovis canadensis
Oregon's Big Horn Sheep and Rocky Mountain Goat Management Plan (PDF)
United States Geological Survey


© 2002 San Diego Zoo Global. Last update 2002. Disclaimer: Although San Diego Zoo Global makes every attempt to provide accurate information, some of the facts provided may become outdated or replaced by new research findings. Questions and comments may be addressed to library@sandiegozoo.org.

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