The Peary caribou (Rangifer tarandus pearyi) is a subspecies of caribou found in the High Arctic islands of Nunavut and the Northwest Territories in Canada. Peary caribou were named after the American explorer Robert Peary. They are called tuktu in Inuinnaqtun/Inuktitutand (Inuit language of Canada) and are the smallest of the North American caribou.
The coat of the Peary caribou is white and thick in the winter. In the summer it becomes short and darker, almost slate-grey in color. The coat is made up of hollow hair which helps to trap warmer air and insulate the caribou. Both the males and females have antlers. The males grow their antlers from March to August and the females from June to September, and in both cases the velvet is gone by October.
Peary caribou are found on High Arctic islands, including Banks Island, the northwest corner of Victoria Island, Prince of Wales Island, Somerset Island and the Queen Elizabeth Islands. They also occur in Aulavik National Park at the northern end of Banks Island. In summer they search for the richest vegetation which on the upper slopes of river valleys and uplands and in the winter, they remain in rugged uplands, beach ridges and rocky outcrops where the snow is not too deep. Peary caribou may move seasonally up to 150 km (93 mi) each way, not necessarily on fixed migration routes that are used habitually, but rather broad migration zones that individuals use to travel from winter ranges to calving areas and summer ranges.
Peary caribou usually travel in small groups of no more than 12 individuals in the summer and 4 in the winter. They are diurnal spending the daylight hours in search of food using their sharp and shaped like a shovel hooves to dig through the snow. Peary caribou are very fast animals and are able to outrun even the Arctic wolf, their main predator. They are also good swimmers and will not hesitate to swim across a large lake or broad river
Peary caribou are herbivores (graminivores). They feed on most of the available grasses, sedges, lichen, and mushrooms. In particular, they seem to favor the purple saxifrage and in summer their muzzles become purple from the plants.
Generally, reindeer are polygynous with one male mating with multiple females. At this time, males take part in fights that leave them exhausted and injured. Dominant males control access to groups of females. The males stop eating at this time and lose a lot of their body reserves. The breeding season of Peary caribou takes place in the autumn and depends on the female having built up sufficient fat reserves. The gestation period lasts for 7 to 8 months and females give birth to a single calf. Young males become reproductively mature at 2 years of age and the females are ready to breed when they are 3 years old.
The Peary caribou population has dropped between 1961 and 2016, according to the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). During this period, the number of days with above freezing temperatures has increased significantly, resulting in ice layers in the snow pack. These ice layers hinder foraging and are the likely cause for dramatic drops in caribou population in the future.
According to the Wikipedia resource, the total population size of the Peary caribou was estimated to be 13,000 mature individuals in 2016.