Minnesota moose numbers still down.
Feb 15, 2018 12:55PM
By John Myers of The Duluth News Tribune - February 15, 2018
Northeastern Minnesota’s moose population dropped some over the last year but appears to have leveled off after big declines earlier in the decade.
The Minnesota Department of Natural Resources reported Thursday that its annual winter moose estimate came in at 3,030 moose, an 18 percent decline compared to 3,710 moose in 2017, a decline the agency said was statistically insignificant.
The state conducts an aerial survey each winter, flying helicopters over predetermined quadrants to count moose. Biologists enter those numbers into a formula to determine the overall population across 6,000 square miles of moose range in Cook, Lake and St. Louis counties.
Statistically, the DNR is 90 percent certain that the population is between 4,140 and 2,320 moose.
“While the population appears stable, low numbers of moose are still a major concern for the DNR,” said Tom Landwehr, DNR commissioner, in a statement. “We continue to pursue the best science, research and management tools available to us to help Minnesota’s moose.”
Northeastern Minnesota held nearly 9,000 moose as recently as 2006. But their numbers began to plummet rapidly after that and are now down two-thirds from that recent high level.
Scientists have been studying myriad possible causes for the decline, and they have found a complicated web of reasons. More years with warmer temperatures and less snow, thanks to global climate change, may be pushing other issues, such as allowing deer numbers to increase in the moose range. Deer carry a parasitic brainworm that is extremely fatal to moose (although harmless to the deer.)
Warmer weather also stresses moose, so they eat less and have less fat to survive winter. Warmer winters with less snow also allow more parasites like winter ticks to thrive — some moose can carry thousands of blood-sucking ticks.
Wolves also are a major factor, especially once the moose population began to drop. Wolves are now holding down calf numbers, thwarting any major recovery of the overall population. Cow moose are getting pregnant and having calves, DNR research found, but very few calves are living to their first birthday. Research shows wolves are killing about two-thirds of all calves that die in their first year compared to about one-third of adults per year.
Aging forests with less moose habitat also may be an issue. Scientists have noted that the only areas with increasing moose numbers in recent years are where big fires have occured in the past decade, clearing way for a younger forest that has the type of food moose thrive on.
Still, the fact the population may have found a stable, if still low, level is the only good news in years.
“The stability of moose numbers in recent years provides a reason for some optimism … we’re not facing a significant decline,” said Glenn DelGiudice, the DNR’s moose research leader. “But this year’s results would be more palatable had they reflected the beginning of a turnaround in the population trend.”
This year’s numbers also are confusing any effort to detect if the downward trend has truly reversed or simply slowed.
“While the trend of stability is encouraging, it does not allow us to forecast the future trajectory of the population,” DelGiudice said.
Minnesota once had a large population of moose in the northwestern region, but that population dwindled to nearly zero by the 1990s.
This year’s survey involved flying in 52 survey plots distributed across Northeastern Minnesota’s moose range from Jan. 3 to Jan. 13. The Fond du Lac Band of Lake Superior Chippewa and 1854 Treaty Authority contributed funding and provided personnel for the annual moose survey.