An anonymous reader writes "Scientists have charted the ebb and flow of moose and wolf populations on Isle Royale in Lake Superior for nearly 50 years. Ice bridges to Canada regularly supplied the genetic stocks for much of that time, but have been rare in recent years leading to inbreeding, dwindling populations and developmental deformity for the wolves that inhabit the island. Now, with the first solid freeze in six years, new wolves could join the mix ... or the remaining island dwellers could leave." If new wolves do not appear, or all of the current wolves leave, the moose would end up destroying the native Fir population. The wildlife service is considering introducing new wolves as part of a genetic rescue, or reintroducing wolves should the population reach zero on its own.