Usually in the tundra organisms dont have to worry about competition; the tundra is too big and not many animals can survive against the harsh climate. However, an example of competition could be between a musk ox and a caribou. A musk ox's diet consists of plants such as sedges and grasses, while a caribou's is made of berries, grass and sedge. When food is hard to find musk ox and caribou might have some competition trying to get something to eat. Might be hard to find a musk ox fighting for a sedge with a caribou, though.