Dall's sheep are herbivorous, grazing primarily for grasses and sedges. They inhabit various habitats with many potential forage species. They can consume between 50-120 species of vegetation. In summer, food is abundant and a wide variety of plants is consumed. In the winter, diet is much more limited, nevertheless, 10-15 species are consumed year long.
They select grasses, sedges and forbs when available, but also ingest lichens and mosses in smaller quantities (Nichols and Bunnell, 1999). Wheatgrass, fescues, bluegrass, and sedges are important foods, while clover, peavine, lupines, pasture sage, dwarf willow, and cinquefoil are eaten when available (Blood, 1999).
In the winter, diet is influenced by accumulation of snow on the ranges, and consists mostly of dry, frozen grass, and sedge stems that are uncovered where snow is blown off, and more lichens and mosses than in other seasons (Bowyer and Leslie, 1992). Mineral licks of calcium phosphate or calcium magnesium concentrate are also important in the diet, especially in the spring and summer, to compensate for mineral deficiencies (Bowyer and Leslie, 1992)
Previously, three distinct subspecies were attributed to the name Ovis dalli, but this classification has been changed. The three subspecies included Ovis dalli dalli, Ovis dalli stonei, and Ovis dalli kenainesis, which was restricted to the Kenai Pennisula of Alaska. Studies, including comparisons of blood chemistry, suggest that this population is no different than Ovis dalli dalli (Nichols and Bunnell, 1999). Ovis dalli are known as thinhorn mountain sheep or Dall's sheep and include two subspecies, Ovis dalli dalli, Dall's sheep, and, Ovis dalli stonei, Stone's sheep. They are capable of interbreeding and produce offspring with intermediate coat pelage (Nichols and Bunnell, 1999).
Perception Channels: tactile ; chemical
Federal, state, and provincial governmental agencies are responsible for the management of Dall's sheep populations. Human activities such as mineral exploration, road construction, and aircraft harassment disrupt populations of Dall's sheep (Bowyer and Leslie, 1992). In British Columbia range burning is used to slow population declines by improving the quality of forage in winter (Bowyer and Leslie, 1992). Most of their range remains remote and pristine and populations have remained relatively unaffected by humans . However, wild sheep face a precarious future because they are adapted to a limited habitat that is becoming increasingly fragmented (Nichols and Bunnell, 1999).
Populations are threatened by trophy harvest (especially adult rams), hunting in parks and reserves, and, to somel extent, subsistence hunting by native peoples (Bowyer and Leslie, 1992). Only two populations in Alaska exist for which subsistence hunting is allowed. Annual trophy harvest is restricted to mature rams. Most adult males are harvested by nonresidents who are required to pay special fees, hire guides and outfitters, and who are restricted to specific management areas (United States) or outfitter units (Canada) (Bowyer and Leslie, 1992).
In British Columbia, Ovis dalli dalli have been put on the Blue List of species at risk due to their low number in that province, approximately 500 sheep. Ovis dalli stonei have been downlisted from the Blue List to the Yellow List, due to improvement in population numbers (Shackleton, 1999).
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
There are no known negative effects of Dall's sheep.
Native hunters hunt these sheep for subsistence. However, Dall's sheep are not as popular as other species, because they are difficult to hunt and do not provide as much meat as larger arctic species (e.g. caribou) (Shackelton, 1999).
Positive Impacts: food ; body parts are source of valuable material
Dall's sheep occur in western Canada and the United States. They can be found throughout the mountain ranges of northeast, central and southern Alaska, as well as in the Yukon Territory, the northwest corner of British Columbia, and southwest of the Mackenzie River in the Northwest Territories (Valdez, 1982).
There are two subspecies, Ovis dalli dalli and Ovis dalli stonei. Ovis dalli dalli includes populations found in most of Alaska and the Yukon territories, extreme northwest British Columbia, and the Kenai Peninsula of Alaska. Ovis dalli stonei includes populations found in south-central Yukon and north-central British Columbia (Wilson and Ruff, 1999).
Biogeographic Regions: nearctic (Native )
Dall's sheep have broad habitat preferences in the arctic and sub-arctic regions but are largely alpine animals, living in high mountain ranges. Generally, they inhabit dry mountainous regions and select sub-alpine grass and low shrub communities (Bowyer and Leslie, 1992). They are dependent upon steep, rugged cliffs and outcrops that provide escape terrain from predators. They use nearby open grass and meadows for feeding. In winter they prefer areas with light snowfall and strong winds that remove snow and expose forage (Nichols and Bunnell, 1999)
Most populations occupy distinct summer and winter ranges, although some are sedentary. Migrations are correlated with snow depth, temperature and plant phenology. Most of the year is spent in the winter range in wind-swept areas that expose forage (Bowyer and Leslie, 1992).
Adult males can occupy six seasonal home ranges: pre-rutting, rutting, midwinter, late winter and spring, salt-lick, and summer (Bowyer and Leslie, 1992). Females usually have four ranges: winter, spring, lambing, and summer. Lambs inherit home ranges from older individuals and they return annually to these inherited ranges (Bowyer and Leslie, 1992).
There seems to be no competition with other ungulates in their ranges for food or space. Wolves (Canis lupus) prey on the sheep in regions where their ranges overlap and may decrease the populations severely if no other prey is available. Coyotes (Canis latrans), golden eagles (Aquila chrysaetos), lynx (Lynx canadensis), grizzly bears (Ursus arctos), black bears (Ursus americanus), and wolverines (Gulo gulo) are also predators. Deaths from accidental falls and avalanches are also common (Wilson and Ruff, 1999). Deep snow, low temperatures, high population density, disease, low-quality forage, and predation are primary sources of mortality, especially among lambs (Bowyer and Leslie, 1992).
Terrestrial Biomes: mountains
Average lifespan
Status: captivity: 19.6 years.
Ovis dalli are the only species of thinhorn mountain sheep (Nichols and Bunnell, 1999). The horns are conspicious and sexually dimorphic. They can be either amber or almost transparent. Females have slender horns, while male horns are massive, flaring, and curled. Horns grow annually in both sexes, but, after the first 4-5 years, male horn growth increases greatly and can end up constituting 8-10% of their total body weight (Bowyer and Leslie, 1992). Horns grow in spring, summer, and into early fall when the growth slows down. Horn growth stops during the winter. This start and stop growth pattern results in a pattern of rings on the horns. These rings are called annuli, and can be used to determine age. As rams mature their horns form a circle. A full circle can be reached within about 8 years (Heimer, 1994).
Body size is also sexually dimorphic. Males are about 40% heavier than females, and continue to grow 2 years beyond female maturity at 4 years. Males can weigh between 73 to 113 kg, while females weigh between 46 to 50 kg. Body length also varies from 1.3 to 1.8 m in males and 1.32 to 1.62 m in females. Tail length is between 70 to 115 mm in males and between 70 to 90 mm in females (Wilson and Ruff, eds., 1999).
The pelage consists of a fine wool undercoat and stiff, long, and hollow guard hairs. The winter coat can be thicker than 5 cm (Bowyer and Leslie Jr., 1992). The subspecies, Ovis dalli dalli, has a pure white or creamy white pelage and tail, although variation is present. Some individuals have a black tail, others have slight grey patches often in the middle of the back. Ovis dalli stonei has a grey to black pelage. The inside of the ears are white, while the outsides are grey. The belly is white, as are the backs of the legs. They also have a white rump patch, and a black tail (Shackleton, 1999). A moult occurs from March to July, with mature males moulting before the females, young, and older individuals (Bowyer and Leslie Jr., 1992).
The skin of the face and rostrum is thickened, especially in males. The males also have a double layer of bone on their skulls which allows them to absorb heavy impacts suffered during battles between males (Bowyer and Leslie, 1992).
Dental formula is I 0/3, C 0/1, P 3/3, M 3/3, with 30 teeth total (Bowyer and Leslie, 1992).
Range mass: 46 to 113 kg.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger; ornamentation
Rams can sire lambs at 18 months but do not usually mate successfully until they acheive social dominance and adult size at 5-7 years of age. Females are sexually mature at 30 months and have their first lamb by age 3 or 4. They produce lambs annually after that (Bowyer and Leslie, 1992).
Lambs are born in late May or early June. Ewes seek solitude and protection in the most rugged cliffs to bear their lamb. Ewes give birth and the mother-lamb pair remains in the cliffs until the lambs are strong enough to travel. Lambs begin to feed on vegetation within two weeks of birth, and are weaned after three to five months, usually by October (Heimer, 1994).
Gestation lasts about 175 days, after which a single lamb is born. Twins are rare (Bowyer and Leslie, 1992). The young weigh between 3-4 kg at birth. Females lick and paw the lambs soon after birth (Shackleton, 1999). Lambs can stand for the first time 15-32 minutes after birth, and are able to travel with their mother within 24 hours. The young grow rapidly, and can achieve 27-30 kg by 9 months of age (Bowyer and Leslie, 1992).
The annual rate of increase can be 11-18% in an unhunted population, but mortality of lambs can reach 40-50% by their first winter in populations nearing carrying capacity (Bowyer and Leslie, 1992)
Range number of offspring: 1 to 2.
Average gestation period: 5.7 months.
Range weaning age: 4 to 5 months.
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average birth mass: 2819 g.
Average gestation period: 173 days.
Average number of offspring: 1.
Average age at sexual or reproductive maturity (male)
Sex: male: 639 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 684 days.
Parental Investment: altricial ; post-independence association with parents
El mufló de Dall (Ovis dalli) és una espècie de mamífer artiodàctil de la família dels bòvids. És un mufló salvatge propi de Nord-amèrica; en especial, viu als hàbitats de les Muntanyes Rocalloses, entre la Colúmbia Britànica i Alaska. Té un pelatge blanc característic.
Es reconeixen dues subespècies d'Ovis dali.[1]
El mufló de Dall (Ovis dalli) és una espècie de mamífer artiodàctil de la família dels bòvids. És un mufló salvatge propi de Nord-amèrica; en especial, viu als hàbitats de les Muntanyes Rocalloses, entre la Colúmbia Britànica i Alaska. Té un pelatge blanc característic.
Ovce aljašská (Ovis dalli) je menší příbuznou ovce tlustorohé. Je rozšířena od severní Aljašky po sever Britské Kolumbie. Jsou známy dva poddruhy: Ovis dalli stonei, jehož domovem jsou hory jižního Yukonu a severní Britské Kolumbie, a Ovis dalli dalli, který žije o něco severněji.
Aktuálně (v roce 2018) byl tento druh chován jen ve čtyřech evropských zoo, z toho dvou německých a dále estonské Zoo Tallinn a české Zoo Plzeň. V minulosti byla ovce aljašská v Česku také chována v Zoo Praha a Zoo Dvůr Králové.[2]
V Zoo Praha byla ovce aljašská chována v letech 2008 až 2014.[2] První zvířata přišla z německých zoo v Krefeldu a Lipsku.[2] První mládě se narodilo v roce 2011.[3] Zvířata z ukončeného chovu přešla v roce 2014 do Zoo Plzeň.[2]
Obrázky, zvuky či videa k tématu ovce aljašská ve Wikimedia Commons
Ovce aljašská (Ovis dalli) je menší příbuznou ovce tlustorohé. Je rozšířena od severní Aljašky po sever Britské Kolumbie. Jsou známy dva poddruhy: Ovis dalli stonei, jehož domovem jsou hory jižního Yukonu a severní Britské Kolumbie, a Ovis dalli dalli, který žije o něco severněji.
Samci mají silné, zahnuté rohy. Mladí samci bojují se staršími, ale mají nevýhodu, že mají dosud malé rohy. Doba březosti: 21-26 týdnů Váha jehněte: v průměru 3-5 kgDas Dall-Schaf oder Alaska-Schneeschaf (Ovis dalli) ist eine Art der Schafe, die im nordwestlichen Nordamerika lebt. Es ist zu Ehren des US-amerikanischen Naturforschers William Healey Dall benannt.
Dall-Schafe erreichen eine Kopfrumpflänge von 1,3 bis 1,8 Metern, der Schwanz ist mit 7 bis 11 Zentimetern sehr kurz. Mit 70 bis 110 Kilogramm sind Männchen deutlich schwerer als Weibchen, die nur etwa 50 Kilogramm erreichen. Die Fellfärbung variiert nach Unterart: Bei O. d. dalli ist es meist reinweiß gefärbt, einzelne Tiere können aber einen schwarzen Schwanz oder graue Flecken am Rücken haben. O. d. stonei hingegen ist graubraun oder schieferbraun gefärbt, der Bauch und die Hinterseiten der Beine ist schwarz. Im Winter wird das Fell ausgesprochen dicht und lang.
Beide Geschlechter tragen Hörner, diese sind jedoch deutlich dünner als beim Dickhornschaf. Die Hörner der Weibchen sind dünn und ragen nach hinten, die der Männchen sind deutlich schwerer und größer und drehen sich mit der Zeit ein.
Dall-Schafe leben in Alaska und dem westlichen Kanada. In Alaska bewohnen sie die Gebirgsregionen in den nördlichen, östlichen und südöstlichen Landesteilen. In Kanada kommen sie im Yukon-Territorium, im Westen der Nordwest-Territorien sowie im nördlichen British Columbia vor. Die dunkle Unterart O. d. stonei lebt im Süden des Yukon-Territoriums und in Teilen British-Columbias, die helle Unterart O. d. dalli in den übrigen Teilen des Verbreitungsgebietes.
Dall-Schafe sind vorrangig Gebirgsbewohner, die felsige Graslandschaften bevorzugen. Die meisten Populationen wandern im Winter in tiefergelegene Gebiete ab.
Dall-Schafe haben ein gut entwickeltes Sozialsystem. Die Weibchen leben in Gruppen mit anderen Weibchen und Jungtieren, sie verhalten sich anderen Weibchen gegenüber meist friedlich. Lediglich bei Konflikten um Futter- oder Schlafplätze kann es gelegentlich zu Auseinandersetzungen kommen. Die Männchen leben ebenfalls in Gruppen, die außerhalb der Paarungszeit nicht mit den Weibchen in Kontakt kommen. Innerhalb der Männchengruppen etablieren sie eine Rangordnung, die hauptsächlich durch die Größe der Hörner bestimmt wird. Häufig wird die Dominanz ohne Kampf bestimmt, aber wenn die Männchen annähernd gleich große Hörner haben, kommt es zu einer Auseinandersetzung. Dabei gehen die Tiere mit gesenktem Kopf aufeinander los und stoßen oft aus 10 bis 12 Metern Entfernung zusammen. Dabei kommt es aufgrund des verdickten Schädels selten zu Verletzungen.
Dall-Schafe sind Pflanzenfresser. Im Sommer nehmen sie vorrangig Gräser und Kräuter zu sich, im Winter machen Flechten und Moose einen Teil der Nahrung aus.
Beim Eintreten der Paarungszeit nähern sich die Männchen den Weibchengruppen an. Höherrangige Männchen genießen meist das Paarungsvorrecht, oftmals werden die Kämpfe zwischen den Männchen aber heftiger. Nach einer knapp sechsmonatigen Tragzeit bringt das Weibchen im Mai oder Juni meist ein einzelnes Jungtier zur Welt. Bereits nach zwei Wochen kann dieses erstmals feste Nahrung zu sich nehmen, mit drei bis fünf Monaten wird es entwöhnt. Weibchen werden mit 2,5 Jahren geschlechtsreif und werfen mit drei oder vier Jahren erstmals, Männchen pflanzen sich aufgrund des Sozialsystems erst mit 5 bis 7 Jahren erstmals fort.
Widrige Witterungsbedingungen und karges Nahrungsangebot führen insbesondere bei vielen Jungtieren zum Tod, hinzu kommen die Gefahren durch Abstürze und Lawinen. Natürliche Feinde der Dallschafe sind Wölfe, Grizzly- und Schwarzbären, Kanadische Luchse, Vielfraße, Kojoten und Steinadler.
Schon die Indianer jagten die Dall-Schafe wegen ihres Fleisches und üben diese Praxis in geringem Ausmaß auch heute noch aus. Die Jagd ist unter Kontrolle des staatlichen Wildtiermanagement wie dem United States Fish and Wildlife Service in den USA und Nonprofitorganisationen wie der Canadian Wildlife Federation in Kanada. Insgesamt ist die Art laut IUCN nicht bedroht.
Das Dall-Schaf ist eine der fünf Arten aus der Gattung der Schafe (Ovis). Nahe ist es mit dem ebenfalls in Nordamerika lebenden Dickhornschaf und dem sibirischen Schneeschaf verwandt, mit denen es die canadensis-Gruppe bildet.
Wie oben erwähnt, werden zwei Unterarten unterschieden, die hellere O. d. dalli und die dunklere O. d. stonei. Früher wurden auch die Tiere der Kenai-Halbinsel als eigene Unterart gelistet (O. d. kenaiensis), meist zählen diese Schafe jedoch zu O. d. dalli.
Das Dall-Schaf oder Alaska-Schneeschaf (Ovis dalli) ist eine Art der Schafe, die im nordwestlichen Nordamerika lebt. Es ist zu Ehren des US-amerikanischen Naturforschers William Healey Dall benannt.
Ovis dalli, also known as the Dall sheep or thinhorn sheep, is a species of wild sheep native to northwestern North America. Ovis dalli contains two subspecies: Ovis dalli dalli and Ovis dalli stonei. O. dalli live in mountainous alpine habitats distributed across northwestern British Columbia, the Yukon, Northwest Territories and Alaska. They browse a variety of plants such as grasses, sedges and even shrubs such as willow, during different times of the year. They also acquire minerals to supplement their diet from mineral licks. Like other Ovis species, the rams engage in dominance contests with their horns.
The specific name dalli, is derived from William Healey Dall (1845–1927), an American naturalist. The common name, Dall's sheep or Dall sheep is often used to refer to the nominate subspecies, O. d. dalli. The other subspecies, O. d. stonei, is called the Stone sheep.
Originally, the subspecies O. d. dalli and O. d. stonei were distinguished by the color of their pelage (fur). However, the pelage-based designations have been shown to be questionable. Complete colour intergradation occurs in both O. dalli sheep subspecies (i.e., Dall's and Stone's), ranging between white and dark morphs of the species. Intermediately coloured populations, called Fannin sheep were originally (incorrectly) identified as a unique subspecies (O. d. fannini) with distributions inhabiting in the Pelly Mountains and Ogilvie Mountains of the Yukon Territory.[2] Fannin sheep have more recently been confirmed as admixed individuals with predominantly Dall's sheep genetic origins. Previous mitochondrial DNA evidence had shown no molecular division along earlier subspecies boundaries,[3] although evidence from nuclear DNA may provide some support.[4] Current taxonomy using mitochondrial DNA information may be less reliable due to hybridization between O. dalli and O. canadensis recorded in evolutionary history.[3]
Current genetics analyses using a genomewide set of single nucleotide polymorphisms (SNPs) has confirmed new subspecies range boundaries for both Dall's and Stone's sheep, updating the previous pelage-based and mitochondrial DNA classifications.[5][6]
O. dalli stand about 3 ft (0.9 m) at the shoulder. They are off-white in color, and their coat consists of a fine wool undercoat and stiff, long, and hollow guard hairs. Their winter coats can be over 2 inches (5 cm) thick. O. dalli can live to be 12 to 16 years of age.[7]
O. dalli are sexually dimorphic, which means rams and ewes look different. Rams are larger than ewes and typically weigh between 160 and 180 pounds (70 and 80 kg) at maturity. Ewes weigh approximately 100 to 110 pounds (45 to 50 kg) on average. During the winter, adult sheep may lose up to 16% of their body mass, and lambs and yearlings as much as 40% depending on winter weather severity. O. dalli begin growing horns at about two months old. Ewes have small, slender horns compared to the massive, curling horns of rams. Young rams resemble ewes until they are about 3 years of age. At this point, their horns begin to grow much faster and larger than ewes' horns.[7]
Adult male O. dalli have thick, curling horns. Adult males are easily distinguished by their horns, which continue to grow steadily from spring to early fall. This results in a start-and-stop growth pattern of rings called annuli. Annuli can be used to help determine age.[8]
The sheep inhabit the subarctic and arctic mountain ranges of Alaska, the Yukon Territory, the Mackenzie Mountains in the western Northwest Territories, and central and northern British Columbia. O. dalli are found in areas with a combination of dry alpine tundra, meadows, and steep or rugged ground. This combination allows for both grazing and escape from predators.[8]
O. dalli can often be observed along the Seward Highway South of Anchorage, Alaska, within Denali National Park and Preserve (which was created in 1917 to preserve the sheep from overhunting), at Sheep Mountain in Kluane National Park and Reserve, in the Tatshenshini Park Tatshenshini-Alsek Provincial Park in northwestern British Columbia, and near Faro, Yukon.
Primary predators of this sheep are wolf packs, coyotes, black bears, and grizzly bears; golden eagles are predators of the young.[9] O. dalli have been known to butt gray wolves off the face of cliffs.
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Rams and ewes are rarely found in the same groups outside of the mating season, or rut, which occurs from mid-November through mid-December. For most of the year, rams feed in the best foraging areas to enhance their reproductive fitness. During spring and summer, ewes are more likely to select areas such as steep, rocky slopes with lower predation risk to raise offspring.[10][11]
Social order and dominance rank is maintained in ram groups through a variety of behaviors including head-on collisions. These dramatic clashes involve each ram getting a running start before colliding, horns-first into one another. Other behaviors associated with establishing social order include leg kicks, bluff charges, and dominance mounting. Most of this behavior establishes order year-round, but clashes between males with similar horn sizes intensify as the rut approaches.[8] Ewes occasionally engage in similar competitive behavior over feeding or bedding sites. Young sheep practice such interactions as part of their play.[10] While rams do clash horns, it is done to establish order, not over fights to possess ewes.[8]
Rams are known to occupy up to six seasonal ranges, including different areas used during autumn, rut (or mating season from mid-November to mid-December), midwinter, late winter/spring, and summer, as well as spending time at salt licks.[9][10]
For most of the year, ewes select areas free of snow and close to forage. After lambs are born in May, close proximity to escape terrain as well as nearby forage are important in habitat selection. Ewes and lambs will travel farther from escape terrain to forage when in larger groups.[10]
In the summer, food has a high variety and is abundant. In the winter, food is limited to what is available in snow-free areas, such as frozen grasses, sedges, lichens, or mosses. O. dalli will travel long distances in the spring to visit mineral licks to supplement their diet.[8]
The Inupiat people have a long history of hunting O. dalli that dates back to at least the 16th century. Sheep are valued for their skin, which is used for warm clothing, and their meat, especially in times when caribou are not available. Historically, the sheep were hunted in summer by foot and in winter by dog sled teams. Today, the rugged terrain in which they live still requires foot travel to reach these animals. The dependence on O. dalli for meat and clothing fluctuates with caribou populations. Caribou herds declined considerably in the 1940s, and O. dalli became an important harvest species. Since the 1990s, caribou populations have been large enough to sustain people. Consequently, subsistence harvest of O. dalli is lower now than in the 1940s, but sheep continue to be an important meat source when caribou migration routes shift during the winter or between years.[12]
Where sport hunting is allowed in Alaska's national preserves, hunters can harvest mature O. dalli rams that have horns that are full-curl or greater, have both tips broken off or are eight years of age or older.[12]
Changes in O. dalli abundance, distribution, composition and health may indicate changes happening with other species and ecosystem processes. The sheep live in alpine, or high mountain, areas. These areas are expected to experience significant changes associated with climate change. Changes may include shifts in locations of plant communities (e.g., an increase in shrubs in alpine areas), diversity of plant species (e.g., loss of important forage species for sheep), and local weather patterns (such as increased incidence of high winter snowfall and icing events), which may affect sheep distribution and abundance.[13]
Some species are expected to benefit from climate change while others will not. Shrubs and woody plants typically dominate plant communities at lower elevations. As elevation increases, the dominant plant community transitions to one dominated by low-growing grasses, flowers, and lichens. Warming climate trends, longer growing seasons, and changes in precipitation have the potential to allow woody plant species to find suitable habitat at higher elevations.[13]
As a result, low-growing alpine species may be out-competed or shaded by the encroaching woody plants. Changes in the seasonal availability and diversity of alpine plants may affect O. dalli populations by altering sheep diets and consequently where they can live in mountain parks, as well as ewe pregnancy rates and lamb growth and survival.[13]
This article incorporates public domain material from Dall Sheep. National Park Service. Retrieved 9 October 2021. This article incorporates public domain material from The Social Structure of Dall Sheep. National Park Service. Retrieved 9 October 2021. This article incorporates public domain material from Hunting and Subsistence Use of Dall Sheep. National Park Service. Retrieved 9 October 2021. This article incorporates public domain material from Dall Sheep and Climate Change. National Park Service. Retrieved 9 October 2021. Ovis dalli, also known as the Dall sheep or thinhorn sheep, is a species of wild sheep native to northwestern North America. Ovis dalli contains two subspecies: Ovis dalli dalli and Ovis dalli stonei. O. dalli live in mountainous alpine habitats distributed across northwestern British Columbia, the Yukon, Northwest Territories and Alaska. They browse a variety of plants such as grasses, sedges and even shrubs such as willow, during different times of the year. They also acquire minerals to supplement their diet from mineral licks. Like other Ovis species, the rams engage in dominance contests with their horns.
El carnero o muflón de Dall (Ovis dalli) es una especie de mamífero artiodáctilo de la familia Bovidae. Es un carnero salvaje propio de Norteamérica; en especial habita los hábitats de las Montañas Rocosas entre la Columbia Británica y Alaska. Posee un característico pelaje blanco.
Se reconocen dos subespecies:[2][3]
Carnero de dall.
Ejemplares en la ladera de una montaña en Yukón, Canadá.
El carnero o muflón de Dall (Ovis dalli) es una especie de mamífero artiodáctilo de la familia Bovidae. Es un carnero salvaje propio de Norteamérica; en especial habita los hábitats de las Montañas Rocosas entre la Columbia Británica y Alaska. Posee un característico pelaje blanco.
Ovis dalli Ovis generoko animalia da. Artiodaktiloen barruko Caprinae azpifamilia eta Bovidae familian sailkatuta dago.
Ovis dalli-k bi azpiespezie ditu:[3]
Ovis dalli Ovis generoko animalia da. Artiodaktiloen barruko Caprinae azpifamilia eta Bovidae familian sailkatuta dago.
Ohutsarvilammas (Ovis dalli) lampaiden sukuun kuuluva sorkkaeläinlaji. Vuoden 2008 nisäkäsnimistökomitea suosittelee eläimestä käytettäväksi nimeä alaskanlammas. Myös käännöslainaa dallinlammas on käytetty.
Ohutsarvilammasta tavataan Alaskassa ja Kanadan luoteisosissa. Ohutsarvilammaspopulaation kooksi on arvioitu olevan Kanadassa noin 41 500 yksilöä ja Alaskassa 70000-75000 yksilöä. Kanta on pysynyt vakaana ja laji on luokiteltu elinvoimaiseksi.[1]
Ohutsarvilampaat elävät kuivilla vuoristoalueilla. Ne tarvitsevat jyrkkiä ja rosoisia kallioita, jotka tarjoavat suojaa saalistajia vastaan. Ruokailupaikkoina ne käyttävät avoimia ruohostoja ja niittyjä.[1]
Ohutsarvilammas (Ovis dalli) lampaiden sukuun kuuluva sorkkaeläinlaji. Vuoden 2008 nisäkäsnimistökomitea suosittelee eläimestä käytettäväksi nimeä alaskanlammas. Myös käännöslainaa dallinlammas on käytetty.
Ovis dalli
Le mouflon de Dall (Ovis dalli, Nelson, 1884), est une espèce de mammifères de la famille des Bovidae. Il s'agit d'un mouflon, ou mouton sauvage, des régions montagneuses du nord-ouest de l'Amérique du Nord, allant du blanc au brun ardoise et ayant des cornes recourbées d'un brun jaunâtre.
Il y a deux sous-espèces putatives : Ovis dalli dalli, la plus nordique, qui est d'un blanc presque pur, et la sous-espèce du sud, ou mouflon de Stone, Ovis dalli stonei, qui est d'un marron ardoisé avec quelques taches blanches sur la croupe et à l'intérieur des pattes arrière.
Une population intermédiaire, avec un patron de coloration médian existe, parfois appelée Ovis dalli fannini.
Les distinctions entre sous-espèces sont aujourd'hui contestées, les analyses génétiques ne montrant pas des différences marquées entre les populations, malgré les différences de couleurs[1].
L'espèce vit dans les régions subarctiques des chaînes de montagnes de l'Alaska, du Yukon, du Territoire du Nord-Ouest du Canada (les monts Mackenzie) et dans le nord de la Colombie-Britannique.
Les mouflons de Dall peuvent occuper des habitats assez différents des régions sub-arctiques, mais ce sont essentiellement des animaux vivant dans les chaînes de montagnes.
En règle générale, ils habitent les régions montagneuses sèches et mangent des graminées subalpines et de petits arbuste[2].
Ils dépendent des zones raides, des falaises abruptes et des affleurements d'accès difficiles, qui leur fournissent des zones de refuge contre les prédateurs. Ils utilisent à proximité de ces zones d'accès difficile, où la nourriture est rare, des zones plus ouvertes de prairies et de pâturages, pour y trouver leur alimentation. En hiver, ils préfèrent les zones ensoleillées et exposées à des vents forts, lesquels enlèvent la neige et exposent le fourrage qui leur sert de nourriture (Nichols et Bunnell, 1999).
La plupart des populations changent leurs zones d'habitation en fonction des saisons, même si certaines sont purement sédentaires. Les populations qui migrent le font en corrélation avec l'enneigement et l'accès à la nourriture[2].
Lé réserve écologique de Gladys Lake, située au centre du parc provincial de Spatsizi Plateau Wilderness dans la province de Colombie-Britannique au Canada, a été créée en 1975 pour pouvoir étudier le mouflon de Dall dans son habitat naturel.
Les loups (Canis lupus occidentalis), mais aussi les lynx (Lynx canadensis), les grizzly (Ursus arctos) les Coyotes (Canis latrans), les ours noirs (Ursus americanus), et les gloutons (Gulo gulo) sont les prédateurs de l'espèce.
Eu égard à l'environnement où ils vivent, les décès par chute ou du fait des avalanches sont également assez fréquents[3].
Le froid, la faim, les maladies et la prédation sont les principales causes de décès, surtout chez les jeunes[2].
Les mâles vivent en bande hiérarchisée (au sein duquel le rang est surtout établi en fonction de la taille des cornes), séparés des femelles, et ne s'en rapprochent qu'au moment du rut.
Les accouplements se font en novembre - décembre. Ce sont surtout les mâles dominants qui se reproduisent mais pas de façon exclusive.
La gestation dure environ 175 jours. Les petits naissent au printemps. Ils font alors 3 à 4 kilos (Shackleton, 1999). La mortalité des jeunes lors du premier hiver peut atteindre 40 à 50 %[2].
Ovis dalli
Le mouflon de Dall (Ovis dalli, Nelson, 1884), est une espèce de mammifères de la famille des Bovidae. Il s'agit d'un mouflon, ou mouton sauvage, des régions montagneuses du nord-ouest de l'Amérique du Nord, allant du blanc au brun ardoise et ayant des cornes recourbées d'un brun jaunâtre.
Il bighorn bianco o ariete di Dall (Ovis dalli) è una pecora selvatica che vive nelle regioni montane del Nordamerica, in un areale che si estende nei Territori del Nordovest, nella Columbia Britannica settentrionale, nel Territorio dello Yukon e nell'Alaska.Il nome della specie, Dalli, deriva da William Healey Dall (1845–1927), un naturalista americano che le studiò nel loro habitat per un lungo periodo.
La ricerca ha dimostrato che l'uso di queste designazioni di sottospecie è discutibile. L'interazione cromatica completa si verifica tra i manti bianchi e scuri della specie con popolazioni di colore intermedio, chiamate pecore Fannin (O. d. fannini), che si trovano nelle montagne Pelly e Ogilvie nel territorio dello Yukon. L'evidenza del DNA mitocondriale non ha mostrato alcuna divisione molecolare lungo i limiti delle sottospecie attuali, sebbene l'evidenza del DNA nucleare possa fornire qualche supporto. Anche a livello di specie, l'attuale tassonomia è discutibile perché l'ibridazione tra O. dalli e O. canadensis è stata registrata nella recente storia evolutiva.
Si nutre di svariati tipi di erbe e non disdegna muschi e licheni.
Questa specie di ovino appare nei film d'animazione Disney Koda, fratello orso e Koda, fratello orso 2
Ne fa parte anche un esemplare di nome Pina nel manga ed anime Beastars
Il bighorn bianco o ariete di Dall (Ovis dalli) è una pecora selvatica che vive nelle regioni montane del Nordamerica, in un areale che si estende nei Territori del Nordovest, nella Columbia Britannica settentrionale, nel Territorio dello Yukon e nell'Alaska.Il nome della specie, Dalli, deriva da William Healey Dall (1845–1927), un naturalista americano che le studiò nel loro habitat per un lungo periodo.
Het Dalls schaap (Ovis dalli) of dunhoornschaap is een wilde schapensoort die voorkomt in de noordwestelijke gebergtes van Noord-Amerika.
De kleur van de vacht varieert van wit tot lichtbruin. De schapen hebben naar achter gebogen geelbruine hoorns, bij de mannetjes groot en gekruld, in tegenstelling tot de kleinere en zwak gekrulde hoorns van vrouwtjes.
Tijdens de zomer is er volop voedsel voor de schapen, zodat ze zich te goed doen aan een grote variatie planten. In de winter is er veel minder voedsel te vinden en eten ze vooral mos en bevroren gras.
De natuurlijke vijanden zijn vooral wolven, grizzlyberen, coyotes en zwarte beren. Voor de lammeren is ook de steenarend een bedreiging.
Mannetjes leven in kleine groepen en komen bijna nooit in contact met groepen vrouwtjes. Alleen in paringstijd - eind november tot begin december - komen ze bij elkaar. Lammeren worden geboren in mei en een vrouwtje krijgt meestal maar één lam per geboorte.
Het Dalls schaap komt voor in subarctische gebergtes van Alaska, Yukon, Mackenzie gebergte, het westen van de Northwest Territories en het noorden van Brits-Columbia. Ze begeven zich veelal op droog gebied en blijven in de buurt van hellingen met een ruige ondergrond. Hier kunnen ze gemakkelijker ontsnappen aan roofdieren.
Bronnen, noten en/of referentiesHet Dalls schaap (Ovis dalli) of dunhoornschaap is een wilde schapensoort die voorkomt in de noordwestelijke gebergtes van Noord-Amerika.
Tynnhornsau (Ovis dalli), også kalla «alaskasau» og «dall-sau», er ein type villsau som kjem frå Nord-Amerika.
Tynnhornsauen er utbreidd frå Alaska til det nordlege British Columbia. Han lever i mindre flokkar i høgfjell og arktiske område, særleg i bratt fjellterreng.
Sauen har typisk ei kroppslengd på 135–155 cm og skulderhøgd på 93–102 cm. Bukkar veg 90–120 kg medan søyer veg noko mindre.
Avhengig av underart er pelsen kvit eller svart til grå. Underarten som er svart eller grå har også tydeleg halespegel. Horna er store og snodde, men smalare enn hjå tjukkhornsau. Hornmassen er opptil 8–10 kg.
Tynnhornsau (Ovis dalli), også kalla «alaskasau» og «dall-sau», er ein type villsau som kjem frå Nord-Amerika.
Tynnhornsauen er utbreidd frå Alaska til det nordlege British Columbia. Han lever i mindre flokkar i høgfjell og arktiske område, særleg i bratt fjellterreng.
Sauen har typisk ei kroppslengd på 135–155 cm og skulderhøgd på 93–102 cm. Bukkar veg 90–120 kg medan søyer veg noko mindre.
Avhengig av underart er pelsen kvit eller svart til grå. Underarten som er svart eller grå har også tydeleg halespegel. Horna er store og snodde, men smalare enn hjå tjukkhornsau. Hornmassen er opptil 8–10 kg.
Multimedia w Wikimedia Commons Owca jukońska[3] (Ovis dalli) – dzika owca zamieszkująca góry w Ameryce Północnej (Kanada, Alaska).
Owca jukońska (Ovis dalli) – dzika owca zamieszkująca góry w Ameryce Północnej (Kanada, Alaska).
O carneiro-de-Dall ou Thinhorn (do inglês, thin horn, chifre fino), Ovis dalli, é um carneiro selvagem das regiões montanhosas do noroeste da América do Norte, com coloração variando do branco ao marrom (castanho) e que possui chifres curvados de cor marrom-amarelada. O epíteto específico (dalli) é derivado de William Healey Dall (1845-1927), um naturalista americano. Há duas subespécies: o carneiro-de-dall, propriamente dito, ao norte (Ovis dalli dalli) que é quase todo de cor branca, e o carneiro-das-rochas, mais do sul (Ovis dalli stonei), que é marrom com algumas partes brancas no dorso e nas patas traseiras.
Pesquisas mostraram que o uso das designações de subespécies é questionável. Mistura completa de cores ocorre entre as formas brancas e escuras da espécie com populações intermediárias coloridas, chamados Carneiros de Fannin, encontrados nos Montes Pelly e Montes Ogilvie do território do Yukon[1] A análise do DNA mitocondrial não mostrou nenhuma divisão molecular ao longo dos limites atuais das subespécies [2], embora a análise do DNA nuclear possa fornecer alguma sustentação [3]. Também no nível espécie, a taxonomia é questionável, porque a hibridização entre o carneiro-de-dall e o Bighorn foi registrada na história evolucionária recente [2]
Os carneiros habitam as escalas subárticas das montanhas do Alasca (Estados Unidos), o território do Yukon, os Montes Mackenzie nos Territórios do Noroeste, e Colúmbia Britânica setentrional (Canadá). Os carneiros-de-dall são encontrados em locais relativamente secos e tentam permanecer em uma combinação especial de cumes alpinos abertos, de prados, e de inclinações íngremes com o substrato extremamente áspera, a fim de escapar dos predadores que não podem deslocar-se rapidamente através de tal terreno.
Os machos têm chifres densamente ondulados. As fêmeas têm chifres mais curtos, mais delgados, ligeiramente mais curvados. Os machos vivem em bandos, eles associam-se raramente com os grupos de fêmeas, exceto durante a estação de acasalamento no final de novembro e início de dezembro. Os cordeiros nascem em maio.
Durante o verão, quando o alimento é abundante, eles comem uma grande variedade de plantas. Durante o inverno a dieta é muito mais limitada e consiste primariamente em grama e capim seco, congelado que é cavado na neve, e em líquens e musgos. Muitas populações de carneiros visitam reservas de minerais durante a primavera e viajam frequentemente muitas milhas para comer o solo em torno dessas reservas, nutrindo-se assim de minerais importantes para o organismo.
Os predadores primários dos carneiros são o lobo, coiote, urso-negro, urso-cinzento e a águia-dourada (a última é predadora de cordeiros).
Os carneiros-de-dall podem frequentemente ser observados ao longo da Alaska Highway no Lago Muncho na Sheep Mountain no Parque Nacional e Reserva Kluane, próximo de Faro, Yukon (carneiros-de-gannin).
O carneiro-de-Dall ou Thinhorn (do inglês, thin horn, chifre fino), Ovis dalli, é um carneiro selvagem das regiões montanhosas do noroeste da América do Norte, com coloração variando do branco ao marrom (castanho) e que possui chifres curvados de cor marrom-amarelada. O epíteto específico (dalli) é derivado de William Healey Dall (1845-1927), um naturalista americano. Há duas subespécies: o carneiro-de-dall, propriamente dito, ao norte (Ovis dalli dalli) que é quase todo de cor branca, e o carneiro-das-rochas, mais do sul (Ovis dalli stonei), que é marrom com algumas partes brancas no dorso e nas patas traseiras.
Pesquisas mostraram que o uso das designações de subespécies é questionável. Mistura completa de cores ocorre entre as formas brancas e escuras da espécie com populações intermediárias coloridas, chamados Carneiros de Fannin, encontrados nos Montes Pelly e Montes Ogilvie do território do Yukon A análise do DNA mitocondrial não mostrou nenhuma divisão molecular ao longo dos limites atuais das subespécies , embora a análise do DNA nuclear possa fornecer alguma sustentação . Também no nível espécie, a taxonomia é questionável, porque a hibridização entre o carneiro-de-dall e o Bighorn foi registrada na história evolucionária recente
Os carneiros habitam as escalas subárticas das montanhas do Alasca (Estados Unidos), o território do Yukon, os Montes Mackenzie nos Territórios do Noroeste, e Colúmbia Britânica setentrional (Canadá). Os carneiros-de-dall são encontrados em locais relativamente secos e tentam permanecer em uma combinação especial de cumes alpinos abertos, de prados, e de inclinações íngremes com o substrato extremamente áspera, a fim de escapar dos predadores que não podem deslocar-se rapidamente através de tal terreno.
Os machos têm chifres densamente ondulados. As fêmeas têm chifres mais curtos, mais delgados, ligeiramente mais curvados. Os machos vivem em bandos, eles associam-se raramente com os grupos de fêmeas, exceto durante a estação de acasalamento no final de novembro e início de dezembro. Os cordeiros nascem em maio.
Durante o verão, quando o alimento é abundante, eles comem uma grande variedade de plantas. Durante o inverno a dieta é muito mais limitada e consiste primariamente em grama e capim seco, congelado que é cavado na neve, e em líquens e musgos. Muitas populações de carneiros visitam reservas de minerais durante a primavera e viajam frequentemente muitas milhas para comer o solo em torno dessas reservas, nutrindo-se assim de minerais importantes para o organismo.
Os predadores primários dos carneiros são o lobo, coiote, urso-negro, urso-cinzento e a águia-dourada (a última é predadora de cordeiros).
Os carneiros-de-dall podem frequentemente ser observados ao longo da Alaska Highway no Lago Muncho na Sheep Mountain no Parque Nacional e Reserva Kluane, próximo de Faro, Yukon (carneiros-de-gannin).
Oaia Thinhorn (corn-subțire)[1] (Ovis dalli)[2] este o specie de oi originară din nord-vestul Americii de Nord, care variază de la alb la ardezie-maro și are coarne maro-gălbui, curbate. Există două subspecii: numita Oaie Dall sau Oaia lui Dall și subspecia mai sudică, Oaia de stâncă (scris de asemenea oaia stâncii) (Ovis dalli stonei), care este o oaie ardeziu-maro, cu unele pete albe pe partea posterioară și pe partea interioară a picioarelor din spate.
Oaia Thinhorn (corn-subțire) (Ovis dalli) este o specie de oi originară din nord-vestul Americii de Nord, care variază de la alb la ardezie-maro și are coarne maro-gălbui, curbate. Există două subspecii: numita Oaie Dall sau Oaia lui Dall și subspecia mai sudică, Oaia de stâncă (scris de asemenea oaia stâncii) (Ovis dalli stonei), care este o oaie ardeziu-maro, cu unele pete albe pe partea posterioară și pe partea interioară a picioarelor din spate.
Amerikanskt snöfår eller vitt snöfår (Ovis dalli) är en art i släktet får som förekommer i nordvästra Nordamerika. Det vetenskapliga namnet dalli syftar på den amerikanska naturforskaren William Healey Dall.
Djuret når en kroppslängd mellan 1,3 och 1,8 meter och därtill kommer en 7 till 11 centimeter lång svans. Med en vikt mellan 70 och 110 kilogram är hannar tydlig större än honor som bara väger omkring 50 kilogram. Pälsens färg varierar beroende på underart. Pälsen hos O. d. dalli är vanligen helt vid men det finns individer med svart svans eller gråa fläckar på kroppen. Underarten O. d. stonei har däremot en gråbrun päls, buken och baksidan av de bakre extremiteterna är svart. Under vintern blir pälsen tät och tjock.
Horn finns hos bägge kön men dessa är smalare än hos tjockhornsfåret. Honornas horn har vanligen bara en liten krökning bakåt, medan hannarnas horn är böjd i en cirkel.
Amerikanskt snöfår lever i Alaska och västra Kanada. I Alaska förekommer fåret i delstatens norra, östra och sydöstra delar. I Kanada finns djuret i territoriet Yukon, i västra Northwest Territories samt i norra British Columbia. Den mörka underarten O. d. stonei lever i södra Yukon samt norra British Columbia och O. d. dalli i alla övriga regioner.
Habitatet utgörs främst av klippiga bergsregioner. Vanligtvis vandrar djuret under vintern till lägre områden.
Honor lever tillsammans med sina ungdjur i flockar. De är vanligen mindre aggressiva och strider uppstår bara vid meningsskillnader angående födo- och viloplatser. Även hannarna lever i grupper som utanför parningstiden är skild från honorna. I dessa grupper finns en hierarki som främst är bestämd efter hornens storlek. Har två hannar ungefär lika stor horn fastställs dominansen med hjälp av strider. Under striden springer de med sänkt huvud från 10 till 12 meters avstånd mot varandra innan de slår ihop. Sår uppstår sällan på grund av deras tjocka skalle.
Som växtätare har de under sommaren gräs och örter som föda. Under vintern äter de även lav och mossa.
Under parningstiden förenas hannarnas och honornas grupper. Alfahannar har oftast förmånsrätt men ibland uppstår nya strider som är intensivare. Efter dräktigheten som varar i cirka 6 månader föder honan vanligen ett ungdjur. Redan efter två veckor börjar ungdjuret med fast föda och efter tre till fem månader sluter honan att ge di. Honor blir efter 2,5 år könsmogna och föder vid 3 till 4 års ålder för första gången ungdjur. Hannar har på grund av deras sociala beteende först efter 5 till 7 år möjlighet att para sig.
Många ungdjur dör på grund av svåra väderförhållanden eller brist på föda. Dessutom kan de störta från berget eller bli offer för en lavin. Till artens naturliga fiender räknas vargar, grizzlybjörnar, svartbjörnar, kanadensiska lodjur, järvar, prärievargar och kungsörnar.
Vitt snöfår jagas sedan länge av indianerna för köttets skull och i viss mån sker denna jakt även idag. Hannar faller dessutom offer för jakt för hornens skull från Amerikas nybyggare. Trots allt räknas djuret av IUCN inte till de hotade arterna.
Amerikanskt snöfår är en av fem arter i släktet får (Ovis). Dess närmaste släktingar är tjockhornsfåret och sibiriskt snöfår (Ovis nivicola).
Som nämnd skiljs mellan två underarter. Tidigare räknades populationen på halvön Kenai som egen underart, O. d. kenaiensis, men den inkluderas numera i O. d. dalli.
Wikimedia Commons har media som rör Amerikanskt snöfår.
Amerikanskt snöfår eller vitt snöfår (Ovis dalli) är en art i släktet får som förekommer i nordvästra Nordamerika. Det vetenskapliga namnet dalli syftar på den amerikanska naturforskaren William Healey Dall.
Dall yaban koyunu (Ovis dalli), boynuzlugiller familyasından Amerika Birleşik Devletleri (Alaska) ve Kanada'da yaşayan memeli hayvan türü.
Hemen hemen bembeyazdır.
Amerikalı doğa bilimci William Healey Dall (1845–1927)'ın adına ithafen bu adı almıştır.
ABD'ye bağlı Alaska'da ve Kanada'ya bağlı (Yukon Toprakları), Britanya Kolombiyası ile Kuzeybatı Topraklarında yayılım gösterir.
Dall yaban koyunu (Ovis dalli), boynuzlugiller familyasından Amerika Birleşik Devletleri (Alaska) ve Kanada'da yaşayan memeli hayvan türü.
Hemen hemen bembeyazdır.
Розрізняють два підвиди барана Далля:
Іноді окремим підвидом вважається і Ovis dalli kenaiensis з півострова Кенан на Алясці. Однак, як правило, його відносять до Ovis dalli dalli.
Розрізняють два підвиди барана Далля:
Ovis dalli dalli, шерсть якого цілком біла. Зустрічається в більшій частині Аляски і в Території Юкон, а також на крайньому північному заході Британської Колумбії. Його популяції нічого не загрожує. Ovis dalli stonei, сірого кольору з білими плямами біля хвоста. Населяє південь Території Юкон і північ Британської Колумбії. Зник у деяких областях свого споконвічного ареалу, але в цілому не перебуває під загрозою зникнення.Іноді окремим підвидом вважається і Ovis dalli kenaiensis з півострова Кенан на Алясці. Однак, як правило, його відносять до Ovis dalli dalli.
Cừu Dall (danh pháp khoa học: Ovis dalli) là một loài động vật có vú trong họ Bovidae, bộ Artiodactyla. Loài này được Nelson mô tả năm 1884.[2] Đây là loài bản địa tây bắc Bắc Mỹ, bộ lông có màu từ trắng đến nâu đá phiến và có sừng cong màu nâu vàng. Chúng sinh sống trong dãy núi cận Bắc Cực của Alaska, Yukon Territory, dãy núi Mackenzie trong lãnh thổ Tây Bắc Tây và miền trung và bắc British Columbia. Cừu Dall được tìm thấy trong xứ tương đối khô và chúng cố gắng ở trong khu vực kết hợp đặc biệt của rặng núi mở, đồng cỏ, và sườn dốc đứng với mặt đất vô cùng lởm chởm ngay trong vùng lân cận, để cho phép chúng thoát khỏi các kẻ thù mà không thể đi một cách nhanh chóng qua địa hình như vậy.
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Bài viết về chủ đề Bộ Guốc chẵn này vẫn còn sơ khai. Bạn có thể giúp Wikipedia bằng cách mở rộng nội dung để bài được hoàn chỉnh hơn. Cừu Dall (danh pháp khoa học: Ovis dalli) là một loài động vật có vú trong họ Bovidae, bộ Artiodactyla. Loài này được Nelson mô tả năm 1884. Đây là loài bản địa tây bắc Bắc Mỹ, bộ lông có màu từ trắng đến nâu đá phiến và có sừng cong màu nâu vàng. Chúng sinh sống trong dãy núi cận Bắc Cực của Alaska, Yukon Territory, dãy núi Mackenzie trong lãnh thổ Tây Bắc Tây và miền trung và bắc British Columbia. Cừu Dall được tìm thấy trong xứ tương đối khô và chúng cố gắng ở trong khu vực kết hợp đặc biệt của rặng núi mở, đồng cỏ, và sườn dốc đứng với mặt đất vô cùng lởm chởm ngay trong vùng lân cận, để cho phép chúng thoát khỏi các kẻ thù mà không thể đi một cách nhanh chóng qua địa hình như vậy.
Ovis dalli (Nelson, 1884)
Охранный статус
Бара́н Да́лла, или тонкоро́гий бара́н[1] (лат. Ovis dalli) — вид из семейства полорогих (Bovidae), иногда рассматриваемый как подвид толсторога. Видовое название дано в честь американского натуралиста Уильяма Хили Далла[en] (1845—1927)[2]. Ареал его обитания простирается от юга Аляски до Британской Колумбии.
Рога изогнутые, желтовато-коричневого цвета. У самцов они заметно больше, чем у самок. Длина рогов достигает в среднем 1,1 метра, а концы расходятся на расстояние до 82 см. Вес примерно составляет 14 кг. Весят самцы от 55 до 140 кг. Соответственный показатель у самок равен 35-90 кг. Длина тела у самцов равна 1,6-1,8 метра. Самки меньше в длину - 1,3-1,6 метра.
Обитает главным образом на горных лугах выше границы леса (от 600 до 2 500 м над уровнем моря) в группах от 6 до 25 особей. Изредка стадо может состоять из 50 или более экземпляров. Главными естественными врагами тонкорогого барана являются волки, медведи, рыси, росомахи, койоты и орлы. Пища состоит из трав, малых кустарников, веток ив, лишайников и мхов.
Половой зрелости тонкорогие бараны достигают в возрасте 2-3 лет. Гон проходит осенью – в начале зимы. Беременность продолжается 6 месяцев. В основном рождается 1 детёныш, но бывает и двойня, и тройня. Самка производит на свет потомство 1 раз в год. Самое большое число ягнят рождается в мае. В дикой природе баран Далла живёт 13-15 лет. Отдельные особи доживают до 19 лет. Максимальная продолжительность жизни составляет 24 года.
Различают два подвида тонкорогого барана:
Иногда отдельным подвидом считается и Ovis dalli kenaiensis с полуострова Кенай на Аляске. Однако, как правило, его относят к Ovis dalli dalli.
Это заготовка статьи по зоологии. Вы можете помочь проекту, дополнив её. Бара́н Да́лла, или тонкоро́гий бара́н (лат. Ovis dalli) — вид из семейства полорогих (Bovidae), иногда рассматриваемый как подвид толсторога. Видовое название дано в честь американского натуралиста Уильяма Хили Далла[en] (1845—1927). Ареал его обитания простирается от юга Аляски до Британской Колумбии.
白大角羊（學名Ovis dalli）是北美洲西北部特有的一種羊，顏色由白色至淺褐色，有彎曲褐色的角。白大角羊的學名是以威廉·希·戴爾（William Healey Dall）來命名。
白大角羊其下有兩個亞種：北部的Ovis dalli dalli全身呈白色；南部的Ovis dalli stonei呈淺褐色，臀部及後腳內側有白斑。研究顯示這些亞種存有疑問。在育空有一群中間形態的Ovis dalli fannini。[2]粒線體DNA證據顯示這些亞種之間在分子上沒有分野[3]，但細胞核DNA則提供些許支持亞種的說法。[4]另外因為發現了白大角羊與大角羊的混種，白大角羊在物種的層面也有所質疑。[3]
白大角羊分佈在阿拉斯加的亞北極山脈、育空、西北地區的馬更些山脈及英屬哥倫比亞北部。牠們棲息在相對較乾旱的山地，特別喜歡留在遼闊的山脊、草坪及陡坡，因為可以躲避掠食者。
雄性白大角羊有厚而彎曲的角。雌羊的較短及幼長，且輕微彎曲。雄羊聯群生活，很少會與雌羊群有關聯，只會在11月下旬至12月初時的交配季節才會走在一起。幼羊會於5月出生。
在食物豐富的夏天，白大角羊會吃多種的植物。到了冬天，牠們會吃地衣及苔蘚。在春天，很多白大角羊群落都會走到洛磯山雪羊觀賞區覓食。[5]
白大角羊的主要掠食者有狼、郊狼、美洲黑熊及灰熊。金雕會掠食幼羊。
돌산양(학명: Ovis dalli)은 양의 일종으로, 몸무게 수컷 약 90kg, 암컷 약 50kg이다. 큰뿔양에 비하면 뿔은 약간 빈약하고 털색깔은 흰색에 가까우나 지방에 따라 짙기도 하고 옅기도 하다.
알래스카, 캐나다의 산악지대에 서식한다. 암석이 많은 험한 산악지대에서 작은 무리를 지어 살며 암벽을 오르내리는 동작이 매우 민첩하다. 적을 만나면 싸움보다는 날쌔게 바위 위로 피하며 적을 희롱하는 듯한 행동을 취한다.
천적은 퓨마, 캐나다스라소니, 늑대, 코요테, 아메리카흑곰, 회색곰이다.
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