Isle Royale National Park Wolves Recovering

Once threatened with extinction from inbreeding, gray wolves in Isle Royale NP in Michigan's Lake Superior.  The number of wolves dropped to just two before federal officials decided to airlift mainland wolves to the island chain in 2018. The wolf population is now thriving, having established balance to the moose population that was itself threatened due to overgrazing of balsam fir trees, its winter food.  [photo courtesy National Park Service]

Scientists report that the wolf population is now 31.  The wolves are forming three packs with others wandering alone or in small groups. The moose population is now 967, down from about 2,000 in 2019.  Ecologists think that the decline in moose numbers will result in a healthier herd.  Although the relocation effort is considered a success, some wilderness advocates consider the intervention to be ill-advised, calling the new wolf population, "artificial".  Scientists think that the first moose swam to Isle Royale at the turn of the 20th century.  Wolves did not arrive until the 1940s, crossing the winter ice from either Ontario, Canada or Minnesota.  The populations of prey and predator fluctuated over the years due to environmental conditions, but inbreeding among the wolves finally led to a collapse between 2011 and 2018.  Some experts think they should have been allowed to die out.  Other species that have a similar relationship such as the Canadian lynx and woodland caribou could have taken their place. However,  loss of ecological balance on the islands contributed to the decline of forest health.  Balsam fir still suffers from over browsing.

Climate change may cause a return of the inbreeding problem, since ice bridges on Lake Superior occur less frequently now, and the nearest mainland to the archipelago is 20 miles away.  A strong moose might make the swim [photo], but a wolf would have difficulty reaching land as its thick fir becomes waterlogged.  Recent opinion on the matter leans towards human introduction in the early 1900's to create a private hunting ground.  The Washington Harbor Cub, a group of wealthy businessmen, owned buildings on the island as well as access.  Genetic studies show island moose to be related to moose from northwest Minnesota near the Manitoba boarder.  Climate change means that wildlife managers will have to import wolves every decade or so.  Wolves only live five years in the wild on average.  None of the wolves originally translocated from Minnesota, Ontario and Michigan remain alive, but are thought to have produced at least seven litters.

The moose population drop of 28% in one year is the largest ever seen in the park.  But officials are not concerned.  Necropsies show that starvation is still the biggest cause of death, and the moose population has plummeted in the past to 400 or 500 and bounced back. Warming climate, spruce budworm, and tick infestations will remain as challenges to a healthy ecosystem.  Michigan Tech biologist, Rolf Peterson told AP, “The old hands-off approach to managing national parks, figuring everything will turn out OK, is probably not sufficient. Our footprint is all over the entire globe.”  So we must tread with care.