During the Siberian summer, reindeer graze on young roots, fungi, grass, and other vegetation. In the cold winter months, they migrate south and rely on available, but less nutritious food, such as lichen. Increased snowfall during the entire winter in southern areas would result in reindeer having to do what?

The questions have been asked in several important state and regional science exams in the United States. For example: TAKS-Texas Assessment of Knowledge and Skills, New York State Educational Department Regents exams, California Standards Test, etc.