National Geographic : 2019 Sep
The wolves keep three male muskoxen in their sights. To kill one of these animals, which can weigh up to 650 pounds, the pack must learn to cooperate. Muskoxen are one of the few prey animals that work together to form a defensive line. The wolves look for opportunities to isolate one muskox from the protection of the herd. These muskoxen deterred the threat.