Muskoxen are adapted to the Arctic. They live in the tundra where they crossed over from Asia to North America 100,000 to 150,000 years ago. During the spring, the greening of the tundra lays out a feast of willow leaves, tussocks, grass shoots, and flowers. They can be found in the tundra with their muzzles buried in the vegetation, eating up the greenery in preparation for winter. During winter, when the entire tundra is covered in snow, muskoxen use their excellent sense of smell to find food. They use their front hooves to dig through the snow or they drop their head to break through a crust of snow. Their scarce diet includes dried grasses, sedges, willows, and lichen.
Muskoxen live in complex social circles. You may often see a herd of up to 75 muskoxen frolicking through the tundra, loafing in meadows or splashing around in puddles. Late summer and autumn is breeding season for these hairy beasts, but before romance can ensue dominance must be fought for. Bulls will often push each other, lock their horns, or bellow like lions. When danger approaches muskoxen stick together. There clever defense strategy has protected them from wolves and other predators. If there is only a single predator, muskoxen form a line of defense in the direction of that predator. If there are multiple predators the muskoxen form a circle with their heads and horns all facing outward, making the circle impenetrable. Calves will stay near their mother or be at the center of the circle.