VIDEO: Moose populations decline in Minnesota, Ontario

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Moose populations in northeast Minnesota and Ontario are declining because of low survival, reproduction rates. Photo: Unhindered by Talent

Warmer temperatures may be the cause of declining moose populations in northeast Minnesota.

A model by the Minnesota Department of Natural Resources shows moose numbers dropping by 15 percent each year over the long-term, according to an aerial survey.

The agency estimates that there were 7,600 moose in January 2009. That number dropped to 5,500 this year.

There are also fewer baby moose – numbers fell to a record low of 28 calves per 100 cows. Ontario is experiencing a similar decline in reproduction rates, according to  the province’s Ministry of Natural Resources.

Minnesota moose are dying for a number of reasons, said Mark Lenarz, group leader for the department in Grand Rapids, Minn.

The ultimate cause is climate change, but parasites and collisions with vehicles are also killing off individual animals. Nearly 70 percent of 150 adult moose with radio collars have died since 2002 because of diseases and parasites, according the department.

The most common parasite is brain worm, Lenarz said. Virtually all white-tailed deer carry the long, threadlike worm.

“It does not affect deer, but it’s invariably fatal to moose,” he said.

Winter ticks, which attach to moose and feed from their blood, are found throughout Minnesota, Ontario, Alberta and Manitoba. Lenarz found one animal infested with more than 70,000 to 80,000 ticks.

“Needless to say, it’s very irritating,” he said. “Moose tend to rub up against tree and rocks in attempt to dislodge ticks. Consequently, they rub off extensive areas of hair.”

Some moose lose up to 80 percent of their body hair. Death can result from loss of blood or insulation, Lenarz said.

Moose mortality is also caused in part by collisions with vehicles and wolf predation. In Minnesota, approximately 15 percent of 150 collared moose died from fender benders since 2002, according to the department.

Six deaths were the result of wolf attacks in northeast Minnesota.

The opposite is true in Michigan’s Upper Peninsula, where moose have increased slowly due to wolf predation. That’s because the wolves keep deer populations low; thus reducing the chance for moose to contract deadly parasites.

See more below this video from Mike Wendland’s blog for the Detroit Free Press.

“Wolf predation is a very effective control on deer density in such deep snow areas, so essentially there is a deer-free area in winter where moose density is highest,” said Rolf Peterson, wildlife ecology research professor at Michigan Technological University, in an e-mail. “It is possible that this reduces the rate at which moose acquire brain worm, which most moose biologists think is an important reason for the moose decline in Minnesota.”

Moose were re-introduced to Michigan in 1985 and now number in the hundreds, Peterson said.

Peterson studies the wolves and moose on Isle Royale and published a book on the relationship. He’s also chair of the Minnesota Moose Advisory Committee.

The ultimate cause of moose decline in northeast Minnesota is climate change, Lenarz said.

Moose aren’t adapted to warm weather and prefer the cold.

When temperatures exceed 57 degrees in the summer and 23 degrees in the winter, moose have to increase their metabolic rate, Lenarz said. This impairs the animal’s immune system and increases its respiration rate.

“Warmer temperatures from climate change are making ideal conditions for diseases and parasites to become fatal to moose,” he said.

Lenarz isn’t sure what will happen to Minnesota moose. Peterson expects deer populations to increase if moose levels get too low.

The species will likely persist in the foreseeable future, according to a report by the Moose Advisory committee. But monitoring is critical.

The Minnesota Department of Natural Resources conducts aerial surveys every January to observe moose numbers and uses models to estimate the entire population.

The committee also makes yearly recommendations, like keeping white-tailed deer populations low to reduce parasite-related deaths.
“At this point, all we can do it watch,” Lenarz said. “We can manage habitat to make sure we’re not losing it. That may simply delay declining populations.

“There’s no way we can control climate, so there’s not an awful lot we can do,” he said.

*Updated for accuracy 3/16/2010 at 3:25 p.m.

5 thoughts on “VIDEO: Moose populations decline in Minnesota, Ontario

  1. The MN. DNR. did cancel the moose hunt for 2013 and are going to review it next year to see if it going to have a hunt in 2014.

  2. I’m afraid that most DNRs these days are more concerned about the politics rather than about the science and conservation of the resource. Sad, but true. The Michigan DNR seems to be suffering the same fate. I guess it hasn’t been the same since they changed the name from “Department of Conservation”.

  3. I am a hunter. As a hunter I am a conservationist. Why would the DNR still issue tags to hunt the moose? Or are they more interested in revenue sources rather than protecting a resource????enetaiststudents

  4. If the numbers are at historically low levels then why is the DNR still giving out moose permits?

  5. It’s grim to hear the pressure on moose in Northeast Minnesota, but I greatly appreciated Great Lakes Echo running this story. Too many stories have been written about falling moose populations that do not squarely and unequivocally lays the blame where it belongs: climate change.

    My only quibble is the last quote from the researcher that we have no control over the climate. That is the unbearable reality: we most certainly do, and the good news is that if we act aggressively enough, we can avoid the worst consequences of a changing climate. We may not be able to slow climate change fast enough now to save moose in Minnesota, that is true. But the future of the climate is our choice.

    I have traveled in that NE Minnesota/Ontario wilderness in most years, winter and summer, over the past 35 years. I know that it is much more difficult to see a moose than when I was 19. My son has been fortunate, he has seen moose in Minnesota, and when he was 19, he even studied them on Michigan’s Isle Royale with Dr. Peterson. I know that my grandchildren will likely never see a moose in Minnesota.

    I note too that the story did not mention the population of moose in Northwest Minnesota, but I recalled that it was under even greater pressure from high temperatures, its failure to thrive over 57 degrees, and parasites.

    Our friend Mr. Google found the story that I recalled. Now it’s five years old:

    The dying moose herd in northwestern Minnesota
    by Dan Gunderson, Minnesota Public Radio
    February 10, 2005


    “There were about 3,500 moose in 1993. By 2002, the population fell to about 400. In 1995, researchers began putting radio collars on moose and carefully examining the moose that had died. Data collection ended in 2000.”

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