 Once the calves are physically mature, they are able to swim back, and are then able to better protect themselves from wolves, as they are then in their prime years.Initially, it was thought that the wolf and moose populations would reach a stable balance.However, during the nearly sixty years of the study, the populations of both species have fluctuated up and down with the number of moose ranging from a high of nearly 2500 down to 500 and the number of wolves ranging from a high of 50 down to one in 2017/18.