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Statistician W. Edwards Deming stated: "Without data you're just another person with an opinion."

On Nov. 18, the Star Tribune published a column by Dennis Anderson stating that wolves were the primary cause for reduced deer harvest, and that wolf hunting and trapping were needed to resolve this issue.

Perplexingly, Anderson did not provide any statistics or data to back up his claims, but instead relied on anecdotal accounts from a handful of individuals who all stated, from their personal experience, that the number of deer and deer hunters were down, and wolves are to blame.

Some of the folks quoted discussed deer hunting trends in and around the area where we, the Voyageurs Wolf Project, have intensively studied wolves and their prey over the past decade, an area referred to as the Greater Voyageurs Ecosystem (GVE).

The data on wolves, deer and deer hunting success in and around the GVE show that Anderson's assessment regarding the role of wolves on deer and deer hunting was grossly inaccurate. In fact, the data indicates the exact opposite of what Anderson opined.

Anderson used a few individuals' opinions regarding the number of deer harvested and the number of deer hunters to demonstrate that wolves are "decimating" the deer. Both of these are terrible metrics for assessing deer hunting success.

Why? Because the number of hunters in Minnesota and elsewhere has declined substantially with time and that alone should lead to decreased deer harvests.

We see this pattern clearly when we look at the number of deer hunters each year in each Deer Permit Area (DPA) in northeastern Minnesota and compare that to the number of deer harvested each year since 2012 in the same DPAs.

If the accounts in Anderson's commentary regarding drastically decreased deer hunters is correct, then it is no surprise that the number of deer harvested would be lower. This fact was ignored.

The best metric to measure hunting success over time is the number of deer killed per hunter because this accounts for changing levels in the number of deer hunters, and is therefore a good measure of deer hunter success.

We used publicly available data from the Minnesota Department of Natural Resources to calculate hunter success in the DPAs in and adjacent to the GVE and across northeastern Minnesota.

Interestingly, deer hunter success in and around the GVE decreased dramatically from 2012 to 2014, reaching its lowest values in the past decade in 2014 — a pattern that is consistent across northeastern Minnesota.

Yet, this decrease in hunter success occurred during the three most recent wolf hunting and trapping seasons (2012-2014), and when wolf populations in the state were at their lowest levels over the past decade.

In fact, in 2014, after two years of wolf hunting and trapping, deer hunter success was lower than it was before wolf hunting and trapping began, and even lower than hunter success last year (2022).

Further, in 2015, after three years of wolf hunting and trapping, hunter success was similar to the levels observed during 2020-2022.

In other words, killing up to 16% of the wolf population annually during 2012-2014 did not improve deer hunting during this period or shortly thereafter. These facts stand in direct contrast to the thinking expressed in the Anderson column.

Furthermore, wolf populations in the Greater Voyageurs Ecosystem and the state of Minnesota reached their highest levels in the past nine years in 2017 and 2018 — precisely when deer hunter success in northeastern Minnesota was at the highest levels observed over the past decade.

Interestingly, when we compare deer hunter success with annual wolf population size in and around the GVE we see a positive, not negative, correlation. In other words, deer hunters are more successful when there are more wolves around.

Some might be incredulous reading that last sentence. How could that possibly be true? The answer is simple: Wolf populations increase with deer populations. Hunter success also increases with deer populations. Thus, wolf populations and deer hunter success are both driven by deer populations.

And what drives deer populations in northern Minnesota? Most importantly, winters and habitat.

What do 2014, 2022 and 2023 — years when hunter success and deer populations have been at their lowest — all have in common? Long, snowy winters. Any biologist could have predicted in April of this year that deer hunter success was going to be low given winter conditions.

Anderson and others who share his perspective appear to want the public to believe that wolves are decimating deer populations and that killing wolves will help deer populations and deer hunting success. They ignore clear and publicly available evidence that completely contradicts what they claim is occurring.

Deer populations are driving wolf populations, not the other way around. That is why deer hunters are generally more successful when there are more wolves around.

Readers can find a detailed assessment of the relationship between wolves, deer and deer hunting in the Greater Voyageurs Ecosystem and Northeastern Minnesota here: voyageurswolfproject.org/wolves-deer-hunting-data.

Thomas Gable is the project lead for the Voyageurs Wolf Project and a postdoctoral associate at the University of Minnesota. Joseph Bump is a full professor and Austin Homkes is a researcher at the University of Minnesota's Department of Fisheries, Wildlife and Conservation Biology.