ELY— University of Minnesota researcher Dr. Tom Gable, on Tuesday, waded deeply into northern Minnesota’s hottest wildlife management debate— the connection between wolves and the recent struggles of the region’s white-tailed deer population.
Speaking to about 60 people at the Ely State Theater, Gable provided some of the results of his decade-long Voyageur Wolf Project, an ongoing study of wolves in and around Voyageurs National Park.
He was there to, in some ways, set the record straight. At a time when many deer hunters in the region are convinced that wolves are behind the recent decline in deer numbers, Gable’s research has consistently pointed to winter severity as the primary driver of deer numbers in the region. That’s a conclusion that is consistent with virtually every study ever conducted on white-tailed deer in northern climates, but the public nature of much of Gable’s research, which has attracted a broad following on Facebook, has left him the target of ire among some hunters. He’s faced accusations of being anti-hunting, a claim that he addressed on Tuesday with a bit of his own personal history, including his and his family’s long-standing interest to deer hunting.
Gable said he is making that point in hopes of dispelling some of the attacks on his research. “Suggesting I have a bias against hunting, well, nothing could be further from the truth,” he said.
Decline in hunter success?
While the deer harvest has declined sharply in northeastern Minnesota in recent years, Gable said that fact is driven by several factors, lower deer numbers being only one. He said as much as a 50 percent decline in the number of hunters in some permit areas, such as 119, in the region, has played a major role in the number of deer harvested in those areas. “Even if hunter success was the same in these areas, you would expect to see fewer deer harvested,” he said. Given that total harvest, not hunter success, typically drives media coverage of the deer hunt, he said there’s a misperception that deer hunting is worse than it actually is. “There has been a decline in deer harvest success,” notes Gable, “but it’s not as great as many people believe.”
Winter’s impact
While Gable’s research focuses on wolves, it also monitors and estimates deer populations in his study area and he said both wolf and deer numbers tracked remarkably well for the first several years of his research. That was upended by back-to-back deep snow winters in 2022 and 2023, years in which deer numbers dipped sharply, while wolf numbers jumped as wolves feasted on weakened and dying deer.
But the decline in deer numbers soon impacted wolf numbers in his study area. The record mild winter of 2023-24 turned the tables, minimizing winter mortality for white-tailed deer and beginning a sharp decline in wolf numbers in the study area, to a level only seen once before in the ten-year study. That’s a connection that Gable said has been well documented in other studies in North America, which find that wolf densities are clearly connected to the density of their prey. Indeed, wolf numbers are much more dependent on deer density than deer numbers are connected to wolf density.
Gable said from what he hears from some hunters, there seems to be a belief that wolf numbers can rise continuously, even in the absence of a prey base. But that’s simply not the case, as his and other studies have repeatedly demonstrated.
Gable’s study, like those before it, has confirmed that deer numbers, and the success of deer hunters, rise and fall based primarily on winter severity. And the most recent dip in deer numbers are clearly linked to the severe winters of 2021-22 and 2022-23.
Gable said deer numbers in the study area grew by about 10 percent in the wake of the record mild 2023-24 winter and he expects to see an increase in deer numbers again this year as a result of last winter’s mild conditions.
Habitat a factor
While winter severity is the key driver of deer survival in northern Minnesota, Gable said it’s clear that habitat factors can play a role in the ability of deer to survive harsh conditions. “We need to talk about what deer actually need,” he said, while noting that current forest management on public lands isn’t helping deer. He cites aerial images from inside Voyageurs National Park and areas outside the park to highlight how conifers are disappearing from the landscape in many cases. He notes that wildlife managers from around the region have been making this argument for years, but that it has yet to break through with the DNR’s forestry division, which is focused on maintaining timber harvests. He noted that during winter, deer require the cover offered by conifers and spend most of their time in such pockets of cover. As those areas disappear due to intensive logging, deer survival suffers.
But wouldn’t a wolf hunt help deer?
For many hunters, the best way to help the deer population recover is with a wolf hunt. Yet, according to Gable, there’s little reason to believe that a wolf hunt in Minnesota, even an aggressive one, would have any impact on wolf numbers, since wolves are capable of reproducing quickly and have repeatedly shown an ability to sustain their populations at carrying capacity even with annual hunting mortality of more than 25 percent.
Based on the current wolf population estimates, Minnesota’s current state wolf management plan calls for harvesting 10-20 percent of the state’s wolf population, a level that would have little detectable effect on the state’s wolf population.
Gable noted that the states of Idaho, Montana, and Wyoming have tried to control their wolf populations with aggressive hunting seasons, largely without impact. He cites a 2023 report from the Idaho Fish and Game Department, which reported that despite a wolf hunt that took an average of 33 percent of that state’s wolves from 2019-2021, annual reproduction was able to replace 100 percent of the wolves killed by hunters.
Gable cites data from right across the border in northwestern Ontario that shows hunter success there tracks almost exactly with hunter success in deer permit areas that abut the border here in Minnesota. That’s despite the fact that Ontario has allowed wolf hunting for decades.
There’s even data from Minnesota proving the point, notes Gable. Minnesota conducted a fairly aggressive wolf hunt from 2012-2014. “Yet hunter success declined sharply during the three wolf hunting seasons,” he said, while the wolf population remained stable.
While those years coincided with two severe winters, Gable says that just proves that winter severity is the driver of hunter success, and a wolf hunt would make little difference in deer survival.
“That’s because wolves are not the primary factor driving deer numbers,” he said. He compared a wolf hunt to squeezing a stress ball. “It just makes some people feel better.”
Gable said he has no opinion on whether a wolf hunt should be held in Minnesota, since it’s a value decision that science can’t address. But he said it’s a decision that should reflect the views of the overall public, rather than certain groups that might have strong opinions.
“Wildlife is held in a kind of public trust,” he said. “Management should reflect what everybody wants.”