DNR biologists concerned about late U.P. winter impacts on deer

A map shows Upper Peninsula snow depths
With more snow predicted for the region this weekend, the prolonged wintry conditions being experienced in the Upper Peninsula show no sure signs of relenting soon, a circumstance that has state wildlife biologists concerned about the stressful impact to white-tailed deer.

“A month ago, we were optimistic about the deer herd, with spring on the horizon and the winter we’d had to that point,” said Terry Minzey, Upper Peninsula regional wildlife supervisor for the Michigan Department of Natural Resources. “Now, I’m quite concerned with what we might end up with because of this protracted winter weather.”

Deer radio-collared in the western U.P. as part of an ongoing predator-prey study or a new deer migration study, have suffered a 13.5 percent mortality rate so far this winter, with 11 percent of adult female deer dying.

That mortality rate compares to 15 percent through the entire month of April in 2017.

“The big difference between this year and last year is that as of April 11 last winter, 95 percent of the deer had dispersed from their wintering complexes,” Minzey said. “This year, there have been none. They’re all still there because of the continuing winter conditions.”

An April 9 snow depth map showed more than 2 feet of snow in some northern parts of the region, nearly 2 feet of snow in other places, and several inches on the ground in areas traditionally green with grass by this time of year.

Some snow depth examples included 20 to 26 inches in Hulbert, 12 to 17 inches in Gwinn, 15 to 19 inches at Baraga, 16 to 17 inches at McLain State Park north of Hancock and 17 to 21 inches at Wakefield.

“In general, across the north and west, the deer are starting to look pretty rough and stressed,” said Brad Johnson, a DNR wildlife technician at Baraga. “The Keweenaw is almost up to 300 inches of snow (for the season) and we are listening to Tiger baseball on the truck radio 5 miles out on 2 feet of ice in Lake Superior in April.”

Johnson said DNR staffers are starting to get a lot of calls of stressed deer reported at feeding sites.

Minzey said this winter is different than most others because a comparatively low amount of snow fell during the early part of the winter. Temperatures remain below average for April so far.

“With relatively no green vegetation available, deer are suffering a negative energy balance at the same time they are burning energy used for developing fetuses or antler development,” Minzey said. “Deer expend five times more energy to move through snow than they expend to keep warm.

“Generally speaking walking in 14 inches of snow results in a 50 percent energy expenditure increase as compared to walking on dry ground. If deer are forced to walk through 21 inches of snow, they burn twice the energy compared to walking on dry ground.”

Minzey said when these snow, weather and health conditions exist after mid-March, it typically spells trouble for fawn, and potentially adult deer, survival.

In some areas, the only snow-free areas are along roadsides where deer are congregating and getting struck by passing vehicles.

“Up until a month ago, I would have said that is was 20 percent of fawns that looked like there were in rough condition, or at least starting down that path,” said Kristie Sitar, DNR wildlife biologist at Newberry. “These last two weeks, about half of fawns look like they are not going to make it. Most adults look still fairly decent.”

At Sault Ste. Marie, DNR wildlife biologist David Jentoft said most of the deer he’s seen on the far east end of the peninsula still look OK.

“Deer movement was not heavily restricted for most of the winter in eastern Chippewa and Mackinac (counties), as snow depths have not been real deep, so that likely has helped,” Jentoft said. “Having said that, deer don’t seem quite as responsive as they were a couple of weeks ago. If the winter conditions hold on a lot longer, deer condition may deteriorate.”

At Crystal Falls, DNR wildlife biologist Monica Joseph said most deer look skinny, but OK.

“They still seem willing to run off and jump banks, so they still have some energy reserve,” Joseph said. “We are likely losing fawns as some are looking bad, and with persistent snow cover and significantly more snow forecast for the weekend, they are going to be stressed even more. No observations of dead adult deer, due to winter loss, have been reported.”

Similar reports were received from Shingleton where deer were observed at northern feeding sites and in the southern part of the Cusino wildlife management unit.

“Most of those deer are skinny, but don’t look like they’re quite on their last legs yet,” said Cody Norton, DNR wildlife biologist. “I’m sure they are getting pretty susceptible to predation and other forms of mortality though, and the coming storms could definitely push them over the edge in much of the unit.”

In Delta and Menominee counties, deer observed looked to be in good condition, according to DNR wildlife biologist Karen Sexton and wildlife technician Colter Lubben.

“I was out working late last night running on sick/injured deer and I made it a point to look at fields of deer and large feeding sites. I looked closely at the fawns and I can say that out of the 150 plus fawns I observed I didn’t see a single fuzzy face or any that I could see ribs or hip bones,” Lubben said. “The deer are still very active; chasing each other, running from moving vehicles, et cetera.”

Sexton said fields were mostly open during the last week of March and then snow-covered from April 1 until a few days ago.

At the Marquette DNR office, during the past month, folks who have been feeding deer have reported the number of deer observed has increased by 20 to 50 percent.

“Overall, my forecast for the northern deer is poor if the weather doesn’t turn soon,” said DNR wildlife technician Caleb Eckloff. “Southern deer in my work area are faring much better, but I still have reservations about a successful fawn crop.”

Overall, with improving winter conditions, the Upper Peninsula deer herd had been rebounding over the past year or so, after three consecutive hard winters in which significant deer mortality was recorded.

A hunter camp survey released in February reviewed last fall’s deer hunting season. Across the region, hunters said the number of deer seen and the percentage of hunters harvesting a buck had increased, while they said the deer herd trend and rating of the season had improved.