Wolf Populations: Why Accurate Numbers Might Not Exist

Bernhardt’s words were carefully chosen to further drive home the point that the DOI believes wolves have recovered and are in no danger of slipping back to the point of needing federal protections. This could mean hunters and trappers in the Great Lakes Region will see a wolf season in the years to come.

It also means that the usual suspects who oppose wolf hunting and trapping will be ready to debate the meaning of “recovered populations.” They’ll cite wolf population estimates by individual game agencies. But, if you dig into how wolves are actually counted in any given state, it’s reasonable to believe we’ve been given conservative numbers and that the overall gray wolf population is actually much higher.

Minnesota currently boasts the highest population of wolves in the Lower 48. The most recent count ended up at 2,655 wolves in 465 packs—far above the 1,400 wolves necessary to deem them federally recovered.

According to a recent press release from the Minnesota DNR, the margin of error in the current surveying methods is +/- 700 wolves. To get those numbers, biologists depend on radio collaring a representative sample of wolves in packs throughout the established range. Radio collaring is costly and logistically difficult in many places, so the DNR also heavily relies on sightings, track locations, scat and howling incidences to determine the population.

According to the Minnesota DNR’s furbearer/wolf research scientist, John Erb, there isn’t any technology on the horizon that will increase confidence levels in populations estimates.

“The wolf collars we use today do provide us with more data than ever. They allow us to delineate wolf distribution and estimate home range size more accurately, but they aren’t game changers. Since we use opportunistic observations from natural resources’ staff—which has some sampling weaknesses—we are open to new methods. We’ll consider developing a systematic grid of trail cameras, perhaps deployed by citizen scientists, to give us more consistent and widespread sampling.”

In further efforts to keep tabs on the wolves, Erb and his team conduct a wolf range assessment every five years to outline primary wolf range and whether it is stable, contracting or expanding. Since 1989, the total wolf range has nearly doubled in size, with most of the growth coming during the last decade. This is undoubtedly due, at least in part, to improved surveying capabilities.

But what does all of this mean? At the very least, the wolf range is on an expansion trajectory in Minnesota. More areas are occupied by wolves, which seems to simply suggest there are enough wolves to move the boundaries from their traditional ranges, where they are counted, to non-traditional ranges where they aren’t. It also means that with the methods available, the count can easily be off by 25% or more, depending on where new packs are established and who’s around to record their existence.

Across the river in Wisconsin, the DNR counts gray wolves via radio telemetry, summer howl surveys, winter snow track surveys, recovery of dead wolves, depredation investigations and collection of public observation reports. The most recent count pegged the state’s population at a minimum level of 905 to 944 wolves. Using the minimum level for wolf counts is a testament to the conservative nature that game agencies have taken with the protected species, which begs the question of how much we might be undershooting the actual populations.

Tallying actual numbers of Great Lakes wolves (which includes Michigan), is no easy task given the dense habitat and sheer rurality of many areas where the dogs thrive. It’s nothing like keeping tabs on the wolves in the Northern Rocky Mountains, though, where the population is currently managed by several states, including Wyoming, Montana and Idaho.

Idaho, for example, in the past hasn’t devoted resources to counting individual wolf numbers. Instead, they estimate how many packs are in the state and then extrapolate that number with what the average pack size usually contains, which is between six to nine wolves. The most recent numbers offered in 2018 provide a range of 540 to 810 wolves.

According to Idaho Fish and Game biologist Jim Hayden, there are noticeable flaws in that method, which is why the state is moving away from counting wolves that way.

“Idaho no longer tries to estimate the number of wolves by estimating the number of packs, mean pack size, and the proportion of wolves not associated with a pack. That worked OK when there were fewer packs and most packs were collared, but as the numbers of packs grew, it became very difficult to track.”

Hayden cites a lack of resources and the nomadic nature of wolves as the primary reasons for giving up the old methods of estimating.

“The number of wolves changes every day, and a wolf population of 1,000 in May this year might only be 600 by next April, but could be back up to 1,000 again by the end of the following May. Plus, a border pack might be in Idaho one day, British Columbia for the next two months, and then Montana for a month before coming back to Idaho.”

Most folks who have stomped around the Gem State would tell you that the current wolf estimate probably feels low, especially if you hunted elk or mule deer there during the wolf resurgence. Consider that in 2018, hunters and trappers combined for 312 wolf kills, and wildlife services notched another 83. Even if the top end of the estimate at over 800 wolves were true, that would mean roughly half of the entire state’s population was scratched off of the landscape through legal hunting and trapping, or in response to livestock conflicts.

That only accounts for legal take. In Wisconsin, illegal wolf harvest is believed to have caused nearly 10% of the known mortality in the state’s population. While it’s hard to believe that a Rocky Mountain state with legal harvest methods would approach that level of illegal wolf kills, it’s safe to assume the number of wolves that are illegally killed and not reported is also not zero.

What does all of this mean for the future? Given the recovery of populations well beyond the parameters of the Endangered Species Act, as well as the expansion of wolves in new states like California, Oregon and Washington, it’s likely the gray wolf is going to loom ever larger in wildlife management discussions.

One thing is certain if you take a close look at how wolves are counted: There are likely far more of them on the landscape than agencies report. With every state publishing numbers on the low end of estimates, we could be managing for thousands more wolves than we know about. It’s easy to accept that getting accurate counts on wild animals is difficult, but there’s more at stake for getting it right in this case.

Feature image via Michael Mauro.