Mar 24, 2007 12:38 pm US/Central
Scientists Stumped By Dwindling Moose Population
St. Paul (AP) ―
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In northwestern Minnesota, which as recently as the mid-1980s had a 4,000-animal moose herd, there's now an estimated 84 moose. Even four years ago, that number was around 250. (File)
AP
What's happening to Minnesota's moose?
That's a question that's stumping state wildlife scientists as they watch the moose, an enduring symbol of the north woods, disappear from the state at what they say is an alarming rate.
In northwestern Minnesota, which as recently as the mid-1980s had a 4,000-animal moose herd, there's now an estimated 84 moose. Even four years ago, that number was around 250.
The area with the most moose, northeastern Minnesota's Arrowhead region, saw its own moose numbers decline 23 percent last year -- from about 8,400 to about 6,500 in the most recent aerial survey.
"The moose is an icon in northeast Minnesota, and they are declining in huge numbers," said Mark Lenarz, the chief moose researcher for the state Department of Natural Resources. "Unless we can identify something we can do with habitat management, I'm not sure there is anything we can do."
Minnesota is on the southern range of North America's moose population. The animals need cool swamps and forests to survive.
Some scientists have questioned whether warmer climate trends are making Minnesota less habitable for the moose. But that doesn't explain why moose populations in neighboring North Dakota, as well as parts of New England, seem to be doing well.
The decline in northwestern Minnesota is less surprising, and scientists have been tracking it for more than a decade. The region is more agricultural, and has fewer swamps and forested areas.
A 2006 report noted the warming climate, parasites and disease as factors in killing off the northwestern moose.
But scientists are less sure what's going on in the Arrowhead.
Lenarz said moose need cool summers to survive, and he thinks there's a correlation between last year's hot northeastern Minnesota summer with the sharp population decline. Fewer moose died in the cool summer of 2004.
But Lenarz is not ready to conclude that climate warming is the culprit. "It's possible, but I wouldn't draw that conclusion at this time," he said.
Lenarz is embarking on an in-depth analysis of a five-year moose study that concluded this year in northeastern Minnesota. That study tracked 116 moose with radio transmitters, and 80 of them died. Some were from hunters, wolves and collisions with cars, but most of the deaths were unexplained.
Lenarz said poor nutrition was a factor in many of the deaths. Most of the dead moose lacked sufficient fat.
"That makes you sit up in your seat," said Mike Schrage, wildlife biologist for the Fond du Lac Band of Lake Superior Chippewa, which co-funded the recent study.
"That indicates there is a real issue out there with our survival," Schrage said. "We can't sustain a mortality rate like that for very long."
A typical moose death rate in North America is 8 percent to 12 percent for both males and females.
On Friday, the DNR announced this year's moose hunt will be for bulls only, because female moose are the productivity engine for the herd. Lenarz said hunting is not contributing to the decline, and the new rule is only precautionary.
Chippewa officials are worried about the future of an animal that has cultural importance to their tribe.
"Moose have been a part of Fond du Lac culture prior to European settlement," Schrage said.
(© 2007 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)
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