In a notable recovery effort, Isle Royale National Park’s wolf population appears to be on an upward trajectory, with a new study indicating they have more than an 80 percent chance of surviving the next two decades. This finding follows a concerted effort by park officials and researchers who relocated 19 wolves from various locations in 2018 and 2019 to address a dangerously inbred population with only one breeding pair left.
A Pack Built On Inbreeding
The relocated wolves, primarily from Michipicoten Island in Canada, faced challenges as two siblings established themselves as the dominant pair, despite 11 unrelated wolves being available. This pair has produced at least 12 pups, leading to concerns about inbreeding. Researchers found that nearly every pup born during the study was related to this sibling pair or their immediate family.
Inbreeding poses significant risks, including reduced body size, compromised immune systems, and potential decreases in fertility. Experts believe such factors contributed to the previous collapse of the wolf population on the island. Additionally, climate change has limited natural crossings for wolves to increase genetic diversity, as ice bridges to the mainland have become less frequent.
A Cautiously Optimistic Outlook
Despite the inbreeding concerns, surveys indicate a growing wolf population. A count from Michigan Technological University determined that approximately 37 wolves inhabited Isle Royale as of last winter, a rise from about 27 at the end of the study period in 2023. Sarah Hoy, a researcher with Michigan Tech, noted that these increasing numbers suggest a healthy population, albeit with ongoing risks from inbreeding.
Growing wolf numbers have led to new challenges, including increased instances of wolves venturing into campgrounds. In one notable incident during the summer, a wolf entered occupied campsites, prompting park biologist Mark Romanski to implement new food-storage regulations and campsite closures. He emphasized the need for improved visitor management strategies regarding interactions with wildlife.
A Moose Herd Under Pressure
The situation is less optimistic for another key species on the island. Isle Royale’s moose population has plummeted by roughly 75 percent, with numbers falling from about 2,000 in 2019 to 524 this past winter. Notably, no calves were recorded during the winter of 2026. The decline has been attributed to overbrowsing and the lack of balsam fir saplings, a vital food source for moose during winter months.
Sarah Hoy remarked on the difficulty of observing the struggles of both the moose population and the forest ecosystem. Researchers await data to ascertain the long-term balance between predator and prey on the island. For now, the resurgence of the wolf population is considered a success, though it underscores the complexities of managing the interconnected ecosystem of Isle Royale.
