Dolphin-Union caribou

Dolphin and Union Caribou, Dolphin and Union caribou herd, Dolphin-Union, locally known as Island Caribou, are a migratory population of barren-ground caribou, Rangifer tarandus groenlandicus, that occupy Victoria Island in the Canadian Arctic Archipelago and the nearby mainland. They are endemic to Canada. They migrate across the Dolphin and Union Strait from their summer grazing on Victoria Island to their winter grazing area on the Nunavut-Northwest Territories mainland in Canada. It is unusual for North American caribou to seasonally cross sea ice and the only other caribou to do so are the Peary caribou who are smaller in size and population. They were listed as Endangered by Committee on the Status of Endangered Wildlife in Canada (COSEWIC) since November 2017.

Morphology

Pelage

The pelage of the Dolphin and Union Caribou is white in winter and slate-grey with white legs and under-parts in summer like the Peary caribou. The Dolphin and Union Caribou are slightly darker.

Antlers

Dolphin and Union Caribou have the characteristic light slate-grey antler velvet of Peary caribou as opposed to the dark chocolate brown antler velvet of other barren-ground caribou and woodland caribou.

Taxonomy

Rudolph M. Anderson (1913) first described the migration of caribou across the Dolphin and Union Strait and briefly described its cranial and skeletal differences from other barren-ground caribou: crania "much shorter than those of the Great Bear Lake Caribou, with a noticeable fullness or convexity between forehead and nose..." Anderson had seen specimens of Peary caribou, described in 1902 by his colleague Joel Asaph Allen at the American Museum of Natural History, where they had both worked, and he knew these were not those. Morphological differences were later confirmed quantitatively by Thomas and Everson (1982).