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.
Because wolves prey on animals much larger than themselves, they have had to develop rather sophisticated methods of catching their prey. Caribou try to protect themselves from wolves by sleeping on frozen lakes in the winter, where they can see wolves before they get too close. A healthy caribou can usually outrun a wolf across the hard-packed snow on a frozen lake, or across the tundra in the summer. In the summer, caribou swim out into lakes if they cannot outrun a wolf. Although wolves will swim, they are not nearly as fast as caribou.