Dolphin and Union Caribou
Scientific Name: Rangifer tarandus groenlandicus
Other/Previous Names: Barren-ground Caribou (Dolphin and Union population)
Taxonomy Group: Mammals
Range: Northwest Territories, Nunavut
Last COSEWIC Assessment: May 2004
Last COSEWIC Designation: Special Concern
SARA Status: Schedule 1, Special Concern
|Peary Caribou ( Low Arctic population )||Non-active||Threatened|
Image of Dolphin and Union Caribou
Formerly considered as belonging to the Peary subspecies, the Dolphin and Union population is considered a distinct population of the barren-ground caribou subspecies, Rangifer tarandus groenlandicus. Although the pelage and the colour of the antler velvet make them look more like Peary Caribou, Dolphin and Union caribou are clearly distinct from Barren-ground and Peary caribou.
The fact that both males and females have antlers sets the caribou apart from other members of the family cervidae (Moose, White-tailed Deer). In Dolphin and Union caribou, the antler velvet is grey and the finger-like antlers are the colour of ivory. With the exception of females, which occasionally keep their antlers throughout the winter, all caribou lose their antlers after mating. Dolphin and Union caribou are smaller than other Barren-ground Caribou. The pelage is either a rich brown colour or grey and white. Long white hairs hang down from the dewlap along the throat and breast. Like all caribou, this one is very well adapted to the Arctic winter. The short and compact body, small ears, short tail, and extremely hairy muzzle help conserve heat. The long thick winter pelage serves as an efficient insulator. In spring, the pelage becomes shaggy and the back turns brown. The top layer of its summer coat is the colour of slate and sometimes lacks the pronounced flank stripe, and the bottom layer is white. With the exception of a narrow band along the front, the legs are white. The hooves are very short and broad. In addition to two small fingers named ergots or dew-claws, each hoof has two broad, crescent-shaped fingers that support the major part of the animal’s weight, which the caribou uses like a shovel to forage in the snow. In fact, the name “caribou” is probably an adaptation of "xalibu,” a Micmac word that means “the one who paws.”
Distribution and Population
Barren-ground caribou occur from the Alaskan tundra to the Baffin Island tundra in Nunavut. Eight large herds account for most of these caribou. These herds undertake seasonal migrations from the tundra to the taiga — the sparse evergreen forests south of the tundra. Other individuals gather in smaller herds and spend the year in the tundra (half of these are confined to Baffin Island). The Dolphin and Union herd summers on Victoria Island and crosses the Dolphin and Union Strait to winter on the continent in the Northwest Territories and Nunavut. It is difficult to track fluctuations in this caribou population, because censuses designed to estimate its size were conducted at such irregular intervals. Although the Dolphin and Union population was once estimated at 100 000 individuals, it was down to a handful of individuals during the 1920s. In 1996, the population was estimated at about 28 000 animals, which represents one quarter of its historic size.
Dolphin and Union caribou live exclusively in the Arctic tundra in environments that range from relatively flat and featureless areas in the south and west, to mountainous in the north and east. In extreme snow conditions, survival depends on the availability of ridges and other exposed sites with little or no snow and ice, where the caribou can feed on a variety of shrubs, grasses, and herbs in locations with a variety of moisture content. Caribou undertake seasonal migrations between the continent and the Arctic Islands. Dolphin and Union caribou migrate by walking across the sea ice of the Dolphin and Union Strait to winter on the continent. They return to Victoria Island to calve; they spend the summer on the island and breed there in the fall.
Most caribou mate every year during the fall. They generally give birth to a single calf the following spring. On average, male caribou reach breeding age at four years and females at two years. During the breeding season, males frequently engage in fierce fights using their antlers. Females faithfully return to the same sites every year to calve in isolated locations sheltered from predators. Humans are the caribou’s main predator. Wolves, bears, Coyotes, Cougars, and Lynx also feed on caribou. Members of this species can live to the age of 15 years. In winter, when the snow and ice covering prevent them from digging for food (mainly lichen), Dolphin and Union caribou feed on windswept crests and slopes, and in boulder fields where the snow is soft and is not crusted over. During the plant-growing season in the Canadian Arctic, which only lasts two months, caribou enjoy a short period of access to high-quality food. In spring, they feed mainly on sedges and the new leaf growth on willows and other bushes. They also eat flowers, which abound throughout the tundra. As the summer progresses and the quality of the forage declines, caribou go back to eating lichen to build their reserves in preparation for the breeding season. They are also particularly fond of mushrooms. The length of the Dolphin and Union caribou’s seasonal migration is between 300 and 500 km. Since the mid-1980s, these caribou have been migrating to the southern coast of Victoria Island during breeding season and returning to winter on the continent by crossing the newly-formed ice. However, ice formation has been occurring later in recent years, and caribou on the coast have been causing visible damage to the vegetation while they wait for the ice to form.
Even though there are relatively large numbers of Dolphin and Union caribou, climate change poses a serious threat to these animals. Every year, these caribou journey back and forth between the continent and Victoria Island on the sea ice. Climate warming could make these crossings considerably more dangerous, as it would shorten the length of the periods when the ice covering makes it possible to cross. The decreased availability of food in winter is another major factor that could pose a threat to the caribou. Massive famines could occur if food were to become trapped beneath deep snow, surface ice, or crusted snow. Industrial operations, including marine navigation and ice breakers, could threaten these caribou by hampering their seasonal migrations or causing excessive disruptions during critical periods (rut, calving, or foraging). Hunting by the Inuit could also result in a certain amount of pressure on Dolphin and Union caribou, as the harvest to herd size ratio is relatively high. Limiting factors in the Arctic have a cumulative effect. For instance, the intensification of hunting activities in the wake of a harsh winter could have disastrous consequences for the caribou.
Federal ProtectionMore information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
Provincial and Territorial Protection
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
10 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- COSEWIC Assessments (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Orders (4 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
- Recovery Document Posting Plans (1 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
COSEWIC Annual Report - 2004 (2004)2004 Annual Report to the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.
Recovery Document Posting Plans
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