Harsh winters make fining food difficult for deer. Image: cseeman, Flickr
By Kaley Fech
Capital News Service
With a prolonged winter in the Upper Peninsula, the Michigan Department of Natural Resources (DNR) is concerned about the impact the conditions will have on the region’s white-tailed deer.
“Before this last storm that came through, we had a least a foot of snowpack over probably 80 percent of the U.P.,” said Terry Minzey, the Upper Peninsula regional wildlife supervisor for the DNR. With the latest storm, “we’re running anywhere from 18 inches to over two feet of snow on the ground.”
He said that’s unusual for this time of year.
“This late in April, typically we’re seeing daffodils coming up next to the houses, and we’re seeing a little bit of green grass coming.”
With all the snow on the ground, deer cannot find a good source of food. During the spring and summer, deer eat grasses and herbaceous vegetation such as violets and other flowering plants, Minzey said.
In the winter, they’re forced to each the leaf buds on trees and other woody materials, that aren’t nutritious enough to keep up their weight. The deer simply try to sustain themselves until they get to more nutritious vegetation.
“In the winter time, from about mid-December to mid-March, their metabolic rates slow down, so they move less and they need to eat less,” Minzey said. “But even with that, they’re not getting enough food to sustain their weight. And when you get to about the middle of March, their metabolic rates accelerate.”
He called it a “negative energy balance.”
While sportsmen’s clubs in the U.P. feed the deer, they’re running out of food because they hadn’t planned on feeding them this late into the spring, said George Lindquist, the vice president of the Michigan United Conservation Club and a trustee for the U.P. Whitetails Association of Marquette County, said.
Deer can survive between a 15 and 20 percent weight loss during the winter, Minzey said. When they start losing between 25 and 30 percent, they’ll most likely die.
It’s also a lot harder for deer to walk through snow than to walk on dry ground.
“With the snow, not only can they not get at any quality food, they also expend a lot more energy just trying to move around the landscape,” Minzey said. “So it’s a double whammy. There’s a much larger energy drain, and they don’t have the ability to replace that energy.”
After mid-March, deer need a lot more energy, Minzey said. Pregnant does are in their last trimester, and they need more energy to develop healthy fetuses. Bucks are getting ready to develop antlers, so they need additional energy as well.
Pregnant does may not be unable produce a fully developed fetus and fawns may not be born healthy enough to survive, he said.
“There aren’t a lot of deer up here to begin with,” said Lindquist. “And bad weather like this can impact two generations.”
He said that because young deer are so vulnerable, last year’s fawns will be the first to die now, and there won’t be as many fawns born this June.
Lindquist said a loss to the U.P.’s deer population leads to a decline in hunters.
“People get discouraged if they’re seeing low numbers or no deer at all,” he said. “It’s the number one reason people stop coming out.”
Minzey said the DNR won’t know the extent of the snowstorms’ impact in terms of death rates until after the spring.
“We do have some deer radio-collared or GPS-collared in the west end of the UP, and we’ll be able to get some sort of reading of what’s going on there,” he said. “But we won’t really know the full effects until after the snow is gone and we’re able to go out and do some of our springtime surveys.”