Moose populations are declining in Minnesota, according to results of aerial surveys by the state DNR. Moose in Minnesota are at the southern limits of their North American range.

In the northeast, wildlife researchers estimate there are 6,500 moose, down 23 percent from last year’s count of 8,400. The northwest moose population numbered just 84 animals, down from the 2003 survey, which estimated 253 animals. The northwest population, which numbered about 4,000 animals in the mid-1980s, is now concentrated in a narrow strip from Thief River Falls to the Canadian border.

“It’s still too soon to predict the long-term trend for the northeast moose population,” said Mark Lenarz, a DNR wildlife researcher. “In the northwest, results of a recent study suggest climate change, in combination with pathogens and malnutrition caused the decline of the moose population.”

Increasing temperatures could contribute to a declining moose population, Lenarz said, as the animals must expend additional energy to stay cool. “Moose expend energy to regulate their temperature in the warmer months by panting,” he said. “If they’re panting, they can’t eat as much and that saps their energy reserves, making them more susceptible to disease and malnutrition.”

The decline in this year’s survey estimate from northeastern Minnesota was not unexpected. A study of radio-collared moose has identified nonhunting moose mortality that ranged from 9 to 34 percent in the past five years. This year’s nonhunting mortality rate in northeastern Minnesota was 34 percent, Lenarz said. The nonhunting mortality rate for moose is generally between 8 and 12 percent elsewhere in North America.

During the past five years of the study, 80 of the 116 moose that were radio-collared have died. A few have been killed by hunters, wolves, or in collisions with motor vehicles, but the majority appears to have been killed by some unknown diseases or parasites.

“We’ve tested for all of the diseases and parasites known to kill moose yet the cause of death in most cases, remains unclear,” Lenarz said.
Moose are pursued by state and tribal hunters in separate seasons. In the past, hunters who drew one of the state’s once-in-a-lifetime moose permits could harvest either a bull or cow moose. This year, 233 antlered bull-only state permits are available in 30 zones in the northeastern part of the state. There is no hunting season in northwestern Minnesota. The season dates are Sept. 29 through Oct. 14.
In 2006, 2,952 parties applied for the 279 available state permits. State licensed hunters killed 133 bulls and 28 cows, for a party success rate of 60 percent.

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