Adult males average about 35 kg in weight and 1.5 meters in length from nose to tip of the tail, while adult females average 30 kg and 1.4 meters. Primarily, the wolves in the Arctic are white or cream and the coat is thick, composed of long, coarse outer hair and shorter, soft fur underneath. Wolves mate in late March and the females produce litters of four to seven pups in late May or early June. In a den that the mother has dug herself, or in many cases refurbished, the pups are born blind and deaf. Pups remain with their pack for at least the first year to survive.
Peary caribou migrate seasonally among the Arctic islands where they spend their lifetime.
Most caribou vary in size according to their subspecies, and in keeping with other Arctic wildlife, the Peary herds tend to be smaller than other types of caribou in the Northwest Territories. Adult males may possibly reach 100 cm high at the shoulder and 100 kg in weight. The cows band together in groups in high, rocky areas where lichens and grasses are more abundant, and where they will be more protected from wolves. Within an hour of being born, a calf can stand and even follow its mother, and the two have bonded closely in order to distinguish each other among the herd. Arctic wolves hunt both caribou and muskoxen.