The Michigan Department of Natural Resources has released preliminary results from the firearm deer hunting season from the Upper Peninsula. Results show the harvest was down about 5% compared to 2018 and a 10-year average. (Journal file photo)

EDITOR’S NOTE: This is an in-depth look at the recently concluded firearm deer season and discussions and debates that have followed it regarding the Michigan deer herd. More on this topic will be published next week.

MARQUETTE — The 2023 firearm deer season is officially complete. Although there are still deer hunting opportunities happening in December, we know most of our 2023 hunter effort is officially in the books.

Predators

Wolves, more so than other predators, are often blamed for a lack of deer in the U.P.

From 2009 through 2022, the buck harvest throughout all hunting seasons has fluctuated up and down in association with severe winter occurrences.

Meanwhile, wolf population estimates have remained relatively stable, indicating something besides wolves is affecting the deer numbers – that something is severe winters, deer wintering habitat and even summer food availability.

When deer numbers decline, it is not because wolf numbers have increased, and when deer numbers increase, it is not because wolf numbers have declined.

Deer co-evolved with predators and, as such, have developed predator avoidance behaviors (selecting habitat outside of wolf core areas) and physical characteristics that increase survival (fast speed, wide field of view).

Some hunters and others question the results of DNR surveys, which calculate minimum population estimates for wolves in the U.P. (643 average since 2010), with some suggesting the true population is more likely in the range 2,000-3,000 animals.

The DNR acknowledges the number is an estimated minimum calculated during winter surveys when wolf numbers are at their lowest, prior to the birth of pups, which have a relatively high mortality rate.

The DNR has set out hundreds of trail cameras across the region to help assess wolf numbers. This is part of a new survey approach, which is expected to work in concert with the traditional aerial wolf surveys which occur every other winter.

Given the amount of land in the Upper Peninsula providing suitable habitat for wolves (roughly 10,600 square miles), an average pack size of 4.8 wolves and a median wolf territory size of 82 square miles, the number of wolves resulting given these limiting factors would be similar to minimum estimates the DNR is finding in its surveys.

The “Factors Limiting Deer Abundance in the Upper Peninsula” complete report shows that predation from wolves has a relatively small impact on the deer population.

This is because wolves are not the main predator on fawns, and fawn survival is what drives the deer population changes in most years. Other fawn predators include coyotes, bears and bobcats.

In studies elsewhere in the U.S., including some with no wolves present and one with no predators at all, fawn survival rate was measured at 45%.

During the U.P. Predator-Prey study, which took place over nine years (2009-2019) within three varying snow depth zones, indicated the U.P. fawn survival rate was 47%.

While wolves do prey on adult deer, adult deer survival is quite high. Predation from wolves is simply one portion of what impacts our deer herd in the U.P.

Winter conditions

Since 1996, the Upper Peninsula experienced more than three times as many severe winters than between 1980 and 1996, along with three instances of back-to-back and two instances of three consecutive severe winters.

Severe winters are those with more than 90 days with snow depth of a foot or more. Some factors affecting winter snow depth would include climate change and Lake Superior not freezing over, which provides more moisture to generate lake effect snowfall.

Buck harvest was at an all-time high from the late 1980s to the mid-1990s, and winters were noticeably milder during this time.

The consecutive severe winters beginning in 1996 and 1997 have resulted in periodic declines in buck harvest since then. Since 2013, eight of the 11 winters (73%) have been severe, impacting buck harvest, further restricting the growth of the U.P.’s deer herd.

When the duration of snow cover exceeds 90 days, winter is likely to impact deer populations to some degree. The graph also shows the linkage between buck harvest declines and severe winters, while the wolf population estimates remain steady.

Hunter demographics

Reviewing license sales numbers through the end of November 2023, overall, for the state, about 590,000 people obtained a deer tag, which is 1% more compared to last year at this time.

The total number of deer tags sold was 1.3 million which is 2% more than last year. Nonresident hunters continued the decade-long upward trend totaling about 25,000 which is up 3% over last year.

Since 1995, the DNR has sold hunting licenses using an electronic license sales system (i.e., retail sales system). This system has allowed the DNR to maintain a central database containing sales information on every license sold.

This information is used to track changes in the number of deer hunting license buyers.

Among the key findings:

In 1995, deer hunting licenses were sold to 872,000 people, while in 2019, licenses were sold to 582,000 people. This represents a 33% decline or an average decline of 1.7% per year.

Participation has declined with each generation.

The pace of decline has increased in recent years.

The current level of youth recruitment is the lowest we have recorded since 1995.

The DNR predicts that 434,000 people will purchase a deer hunting license in 2030. This represents a 25% decline from the number of license buyers in 2019.

These declines are part of a national trend, with very few exceptions, especially when looking at states that have experienced little to no population growth in decades, like Michigan.

Hunters are getting older on average and recruiting at lower rates.

Over the years, there have been fewer license buyers for all age classes in the middle of the age curve (i.e., between approximately 12 and 55 years of age).

However, there were increased hunter numbers among the youngest and oldest age classes. The increased hunter numbers in the oldest age classes likely represented the rising share of older people in the population as the baby boom generation aged.

In addition, the legalization of crossbow use during the archery season probably increased participation among hunters in the oldest age classes.

The increased participation among the youngest hunters likely reflected the lowering of the minimum age requirements. In 2012, the minimum age requirement to hunt deer with a firearm was eliminated (mentors are required), while hunters had to be at least 10 years old to participate in 2008.