Moose population decline continues

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Moose population decline continues in northeastern Minnesota


According to results of an aerial survey released by the Minnesota Department of Natural Resources (DNR), the moose population in northeastern Minnesota continues to decline.

Survey results revealed lower moose numbers and the proportion of cows accompanied by calves continued a 13-year decline and dropping to a record low of 28 calves per 100 cows.

“These indices along with results from research using radio-collared moose all indicate that the population has been declining in recent years,” said Dr. Mark Lenarz, DNR forest wildlife group leader.

Moose populations are estimated using an aerial survey of the northeast Minnesota moose range. Based on the survey, wildlife researchers estimate that there were 5,500 moose in northeastern Minnesota. The estimate, while not statistically different from last year’s 7,600, reinforces the inference that the moose population is declining. In addition to the decline in the calf to cow ratio, the bull to cow also continued to decline with an estimated 83 bulls per 100 cows. Aerial surveys have been conducted each year since 1960 in the northeast and are based on flying transects in 40 randomly selected plots spread across the Arrowhead.

A study of radio-collared moose in northeastern Minnesota between 2002 and 2008 determined that non-hunting mortality was substantially higher than in moose populations outside of Minnesota. Lenarz indicated that, “combined with the reduced number of calves, the high mortality results in a population with a downward trend.”

The causes of moose mortality are not well understood. Of 150 adult moose radio-collared since 2002 in Minnesota, 103 have subsequently died, most from unknown causes thought to be diseases or parasites. Nine moose died as a result of highway vehicle accidents. Two were killed by trains. Only six deaths were clearly the result of wolf predation.

Analyses by Lenarz and other scientists have indicated a significant relationship between warmer temperatures and non-hunting mortality. “Moose are superbly adapted to the cold but intolerant of heat,” said Lenarz, “and scientists believe that summer temperatures will likely determine the southern limit of this species.”

As recently as the 1980’s as many as 4,000 moose inhabited northwestern Minnesota, an area of agricultural land interspersed with woodlots. The population declined dramatically during the 1990s and currently numbers fewer than 100 animals. In contrast, the northeastern population occurs in wetland-rich forested habitat which presumably provides thermal cover in a warming environment.

In August, a Moose Advisory Committee convened by the DNR released their findings which will be used in the development of a legislatively-mandated research and management plan. They indicated that while climate change is a long-term threat to the moose in Minnesota, moose will likely persist in the state for the foreseeable future. The plan should be ready later this spring and will be open to the public for comment.

The Fond du Lac band of Lake Superior Chippewa and 1854 Treaty Authority contributed funding and provided personnel for the annual survey.

A copy of the aerial survey report is available online.

[Lee Borgersen]

Here's an editorial that also includes some info on the moose.


Deer herd needs time to recover, but DNR decision on moose looms

Ely Echo Editorial

The Minnesota DNR's juggling act of managing the state deer herd is about to get even more difficult if the fate of the moose population becomes part of the equation.

Right now the state must continually find ways to balance the needs of hunters, foresters, land managers and others interested in how many deer there are per square mile. It's no easy task, that's for sure. And the DNR's toolbox is really a simple tool: how permits and licenses to take deer are handed out.

Mother Nature has tools of her own. Here's the top two: the severity of the winter and the number of predators (primarily wolves).

This winter is mild to date and that's good news for a deer herd that took it in the teeth the past two years. Hunters had a tough time harvesting a deer in our neck of the woods this past season. Many blamed a growing wolf population but whatever the reason, the results were plain to see, or in this case, not see.

We did have to smile at the tongue-in-cheek idea put forward by our friend George: "You have to turn in a wolf tail to shoot a buck, two wolf tails to shoot a doe." Maybe he meant tale, not tail.

The DNR measures winter based on two criteria: the number of days with 15 inches or more of snow on the ground; and, the days where the temperature is zero degrees or lower.

Each day can be given zero, one or two points with the cumulative score known as the Winter Severity Index or WSI.

Local readings are taken near Smitty's Resort on Snowbank Lake, at the DNR office in Tower and in Isabella.

This year the results look good for DNR, with the lower the number the less severe of a winter.

As of Jan. 31, Snowbank was at 42 compated to 96 last year; Tower was at 35 compared to 96 and Isabella was at 68 compared to 95.

Snow depth of 15 inches just became a factor at Snowbank and Isabella while Tower has only counted days below zero up to Jan. 31.

"It's pretty mellow this year other than Isabella has 22 inches of snow which is not much for Isabella, it's way behind last year," said DNR wildlife manager Tom Rusch in Tower.

During a tough winter, the WSI numbers would be in the 100 range by now and Rusch knows that even if we do get there, enough winter has passed to lessen the impact on deer.

"We can still get some big dumps of snow but that doesn't add a month to winter like when we get it in December," said Rusch.

So despite talk in some camps of giving the deer a year off, there will be a hunting season in 2010.

"We know biologically we don't have to shut it down, we just have to take pressure off antlerless deer," said Rusch.

Look for the DNR to go to a bucks-only type of season in our neck of the woods.

The wild card is the moose. Here's a population problem with no solution in sight. There is, however, a recommendation to the DNR to apply liberal deer hunting rules in areas where moose are known to habitate.

Should the DNR include that recommendation in its moose plan that is due to come out this year, our deer herd will be in for even tougher times.

Let's hope the big picture is taken into account when decisions are made in St. Paul. We can hope for that anyway.