No end to declining trend in northeast moose herd
St. Paul — The Minnesota DNR’s annual aerial moose survey results are in, and numbers continue to trend downward.
This year’s survey, conducted by helicopter in January, estimated the northeastern moose population at 3,450, down from 4,350 in 2014, though up from 2,760 in 2013.
“The bottom line is that the trend is down,” said Lou Cornicelli, DNR wildlife research manager. “Calf recruitment is low, adult mortality is high, and there really is no way for the population to be increasing. More animals are going out than are coming in.”
In 2006, the estimate was 8,840 moose, 60 percent higher than this year’s estimate.
Even when last year’s estimate was up by nearly 1,600 moose, it was the same story. Though the estimates are a useful gauge over a long period of time, they are less useful for drawing conclusions on an annual basis, Cornicelli said.
“The issue with point estimates is that they are estimates,” he said. “There are a lot of things that bounce around when you do a point estimate, which is why we hate reporting point estimates because they paint a partial picture.”
Cornicelli likened the moose survey, which includes 54 routes flown in northeastern Minnesota and has been run every year since 1960, to just another way one might estimate the number of marbles in a jar.
“There are different ways of estimating that, but you don’t know unless you count every marble,” he said.
And there’s no feasible way for the DNR to count every moose inside its borders, he said.
“We refine our methods every year so it reduces the uncertainty, but it will never be perfect,” Cornicelli said. “We do our best to minimize the error and detect the trends.”
The full survey is online at www.mndnr.gov/moose
DNR researchers are heading into their third year of concurrent studies looking separately at both adult moose and calves, trying to figure out why they are dying. On Monday, field biologists began the task of capturing and GPS-collaring 36 adult moose for the DNR’s adult mortality study and also for University of Minnesota-Duluth researcher Ron Moen. Another 50 moose calves will be collared this spring, as well.
Already, a range of reasons have contributed to mortality, but it’s still too soon to act, Cornicelli said.
When, then, can the DNR start acting on what researchers are finding?
“The answer I’d give is sooner than later, but I can’t tell you what year that’s going to be because science is a slow process,” Cornicelli said. “One year of information is just one year of information. It doesn’t tell you anything.”
But he acknowledged the clock is ticking.
“We don’t have 20 years to do a project,” he said. “If we wait that long, we might not have any moose left. So those management questions are going to have to be answered sooner than later. With our moose population, we have a finite amount of time to figure it out and do something.”
Cornicelli mentioned a couple of strategies that could be implemented once more is learned – and researchers are currently testing a range of theories, such as the effect warmer weather might have on moose or how much of an issue it might be for moose and deer to be occupying the same areas, even at different times of the year.
“Are they picking up brain worm because they are in the same place, not necessarily at the same time?” Cornicelli said.
The answers are fleeting, he said, because, for example, just because a moose might be killed by a wolf doesn’t mean there weren’t some other underlying causes that made that moose susceptible to being killed by the wolf. By using GPS collars, the DNR is trying to determine underlying causes of death, not just the obvious causes.
Management decisions could mean trying to create more habitat that moose need or something that could be less palatable for some hunters, such as keeping lower numbers of deer in the moose range.
“Are you going to reduce deer densities to benefit moose?” Cornicelli asks. “Somebody is going to like it, and somebody is not going to like it.”
While the Minnesota DNR’s moose-management plan, which was revised in 2011, outlines triggers that would set up the closure of the moose-hunting season, which was discontinued in Minnesota in 2013, it does not outline triggers that would determine when the season would be reopened.
Cornicelli said that was done intentionally, considering the social factors that play roles.
“There would likely have to be some strong indication that the population is increasing over time,” Cornicelli said, stressing that hunting wasn’t causing the problem. “Hunting was the one piece of moose mortality that we can control, but it wasn’t the cause for the decline.”