Why ups and downs?
There is still no good answer. Perhaps there are periodic variations in the food supply. Or, could it be that the number of lemmings is controlled by the number of predators which hunt them?
New questions
During the past fifteen years, populations of lemmings have declined, and the peaks have been smaller.
Answers?
Swedish scientists suspect that these changes are the result of mild winters. The snow cover can be so thin that the rodents, living under it, are poorly protected from their predators – foxes, owls, weasels and birds of prey.
