There are many herbivores living in the tundra, including caribou, musk-oxen, Arctic hares, reindeer, lemmings and porcupines. The lemming is the smallest mammal in the tundra, weighing only between 2 and 4 ounces.
Tundra herbivores eat trees, shrubs, grasses, lichens and moss. Despite the frigid temperatures in this part of the world, there is always plenty for them to eat. The largest herbivore in the tundra is the musk-ox. It can grow to be between 6 and 7.5 feet long and weigh from 400 to 900 pounds. The herbivores of the tundra are hunted by the carnivores. These include polar bears, wolverines, snowy owls and Arctic foxes.