Decline in Minnesota moose count not a surprise to Grand Portage wildlife biologist
As predicted last summer by the top wildlife biologist in Grand Portage, this year’s Minnesota moose count showed a decline in the state’s population of the massive cervids.
In July 2022, Seth Moore, the director of biology and environment for the Grand Portage Band of Lake Superior Chippewa, told WTIP that wildlife officials in the far northeastern part of the state were seeing extremely high adult mortality of moose, much higher than ever before, and extremely high calf mortality as well.
“So I would predict next year’s survey that’s conducted by the Minnesota DNR will show a significant drop in the moose population,” Moore said last July.
It turns out his prediction was correct.
This year’s population estimate of 3,290 moose marks a 30 percent decline from the 2022 estimate, according to the results of this year’s Minnesota Department of Natural Resources’ aerial population survey. The results were made public April 6.
Although the estimate dropped from 2022’s count of approximately 4,700, the change continues to reflect the population stability observed in previous years, according to the DNR. The DNR made a point to mention that Minnesota’s moose count “marks a decade of Minnesota’s moose population remaining relatively stable.”
After a decline from a population estimate of approximately 8,000 in 2009, Minnesota’s moose population appears to have stabilized at about 3,700 animals in recent years, the DNR said this week.
Stabilized doesn’t mean the population is constant, said John Giudice, DNR wildlife biometrician. Instead, annual changes since 2013 appear to be relatively small on average and random, with some years showing a population increase and others a decrease.
But data collected recently by researchers with the Grand Portage Band of Lake Superior Chippewa suggest the magnitude of this year’s decline could be more than an artifact of sampling. They have reported high mortality rates on collared moose and similar decreases in aerial surveys around Grand Portage and at Isle Royale.
As previously reported by WTIP, last spring, in the far reaches of northeastern Minnesota, calf recruitment of moose did not present an uplifting narrative.
“It’s abysmal. I think this is the worst calf recruitment year we’ve seen in 12 years of study,” Moore said during the live broadcast on WTIP last July. “Essentially, of our collared moose, 100 percent of the calves are gone.”
As bleak as that is, during a typical year, an estimated 80 percent of moose calves are taken by predators such as wolves or black bears. Stillbirths also played a factor in the number of moose calves dying last spring, Moore said, following a long winter that was challenging for moose.
Meanwhile, the 2023 DNR survey results showed that calves comprised an estimated 16 percent of the population and the estimated calf-cow ratio was 38 calves per 100 cows. Those estimates are slightly lower than last year’s figures but are comparable to values observed during the last 10 years, especially considering moderate-to-high levels of sampling uncertainty. Both factors are key indicators of reproductive success, according to the DNR.
Both the Fond du Lac Band of Lake Superior Chippewa and the 1854 Treaty Authority contributed funding and personnel for the 2023 annual survey. The survey area is approximately 4 million acres in northeastern Minnesota and includes the Boundary Waters Canoe Area Wilderness.
Click here to learn more about the 2023 moose count and for more information about Minnesota’s moose population.
Joe Friedrichs April 7, 2023
