Dolphin and Union Caribou | NWT Species at Risk

Dolphin and Union Caribou

Caribou [Dolphin and Union population]

Rangifer tarandus groenlandicus x pearyi

NWT List of Species at Risk:

Special Concern

NWT SARC Assessment:

Endangered

Federal Species at Risk Act list:

Special Concern

COSEWIC Assessment:

Endangered

NWT General Status Rank:

At Risk

Description:

Dolphin and Union Caribou are members of the deer family. Like Peary Caribou, Dolphin and Union Caribou have a mostly white coat in winter, and are slate-grey with white legs and under-parts in summer. The velvet covering their antlers is grey. Dolphin and Union Caribou are slightly darker than Peary Caribou.

Report Dolphin and Union Caribou sightings to WILDLIFEOBS@gov.nt.ca

Distribution

Dolphin and Union Caribou are restricted to Victoria Island and the nearby mainland coasts of Nunavut and the NWT. They cross the frozen sea ice between Victoria Island and the mainland twice a year.

Range map information

Habitat and biology

Dolphin and Union Caribou summer on Victoria Island, commonly using beach ridges and river valley slopes. They winter on the mainland in windswept areas with shallow snow cover, primarily in the Bathurst Inlet area of Nunavut. Sea ice is important because they cross the ice between Victoria Island and the mainland twice a year. Dolphin and Union Caribou sometimes gather in large numbers along the southern shore of Victoria Island in the fall, waiting for the sea ice to become thick enough to cross.

Dolphin and Union Caribou are often locally called Island Caribou.

Population size and trends

Dolphin and Union Caribou were at very low numbers during the mid-20th century and had stopped migrating from Victoria Island to the Nunavut-NWT mainland. From the 1970s to the 1990s, numbers increased and Dolphin and Union Caribou resumed migrating across the sea ice. Population estimates indicated that the population was above 30,000 in 1997 but declined to about 18,000 as of 2015, with a further decline to about 3,800 in 2020.

Inuvialuit Knowledge and Inuit Qaujimajatuqagit have also noted a declining trend and changes in distribution of Dolphin and Union caribou. Mortality of Dolphin and Union Caribou due to drowning (breaking through sea ice), predation and hunting is relatively high.

Threats

Potential threats in the Northwest Territories include:

An unknown number of caribou die every fall breaking through the ice crossing to the mainland.
Changes to sea ice freeze-up and break-up due to climate change could threaten migration.
Increased ship traffic may affect ice formation and caribou migration.
Harvest levels in the NWT and Nunavut combined may lead to over-harvesting.
Over-grazing may be an issue in areas where caribou wait before migrating to the mainland for the winter.
Local knowledge indicates an increase in predators across summer ranges; how this affects the Dolphin and Union caribou population is uncertain.
Weather events such as rain-on-snow and melt-freeze can cause an ice crust to form over vegetation.

Protection and recovery

In 2023, the NWT Species at Risk Committee assessed Dolphin and Union Caribou as an Endangered species in the NWT. Previously in 2013 it was assessed as a species of Special Concern, and in 2015 it was listed as Special Concern in the NWT under the territorial Species at Risk (NWT) Act. The potential up-listing of Dolphin and Union Caribou to Endangered in the NWT is under consideration.

Since 2011, Dolphin and Union Caribou have been listed as Special Concern in Canada under the federal Species at Risk Act. In 2017, COSEWIC re-assessed the status of Dolphin and Union Caribou as Endangered in Canada.

In recent years, Inuvialuit and Inuit have taken a series of voluntary and legislated measures to reduce the harvest of Dolphin and Union Caribou in response to the decline.

A management plan for Dolphin and Union caribou in the NWT and Nunavut has been developed and is available here.

Area:

Inuvialuit