Lingering cold, snow taking toll on U.P. wildlife
Marquette, Mich. — There was an extremely mild start to winter in the northern tier of Michigan that had sportsmen and biologists anticipating the fourth mild winter in a row. At the end of January, things changed dramatically. Weather, especially snowfall, became so severe that wildlife managers are now concerned about white-tailed deer.
According to Todd Kubler, meteorologist at the National Weather Service in Marquette, there were a couple snowfalls early on that for the most part melted. On Jan. 29, U.P. residents could still drive on unplowed rural roads.
“From October though the third week of January, we experienced the third least-snowy start to winter in 33 years,” Kubler said. “Then everything flipped, and from the end of January until now we have been back-loaded with system snows, so much so that the second half of winter became the fourth snowiest.”
On Jan. 23, the area was 40 inches below normal. As of mid-April, snowfall had caught up to normal averages, leaving 39 inches of hard-packed snow on the ground. Some areas got hit harder than others.
The Shingleton area received over 300 inches of snowfall. Munising was near 200 inches, double what the area received last year.
“Because they were mostly heavier system snows versus fluffier lake-effect snow, the snow pack now is glacier-like. Every three inches of snow we have on the ground now contains a very high rate of one inch of water,” Kubler said.
With a heavy snow pack, biologists fear a late green-up. This does not only hinder deer survival but may lead to poor health of fawns this year. Deer depend on herbaceous greens in the spring to rebound from woody browse and to provide energy for developing fawns.
“We are starting to get concerned,” Brian Roell, DNR biologist in Marquette, told Michigan Outdoor News. We cracked open some femurs on road-killed deer near the Harlow Lake winter yard, and the marrow was pinkish. A late green-up will result in the birth of runty fawns with lower survival rates.”
The reddening and liquifying of bone marrow is a telltale sign that winter is starting to put a death grip on deer. After a deer burns up fat reserves, the fat in the bone marrow is the last resort. On a healthy deer, bone marrow has extremely high fat content – so much so that wolves key on marrow because it is so nutritious. When the marrow becomes cherry-red, there is no chance the deer will rebound and survive, Roell said. A deer was found in the AuTrain area that only had 30-percent bone marrow fat and apparently died of winterkill.
“When a deer starts using bone marrow fat, their tank is pretty much running on empty,” Roell said.
In the Shingleton area where winter really came down hard, officials also are finding dead deer, according to wildlife assistant Jeff Lukowski. He also reports seeing fuzzy-faced fawns with ribs and hips showing that he doubts will make it.
“We are really, really concerned here,” Lukowski said.
In the Garden Peninsula region, considered the banana belt of the U.P., deer aren’t suffering to the same extent. Lukowski said they are seeing 70-percent bone marrow fat in deer in that area.
On the east end of the U.P. in the Soo area, biologist Dave Jentoft said the first half of winter was mild, but the snow started piling up during the latter half. He reports seeing some fawns not looking as good as they have the past few years. With fairly deep snow on the ground, the deer haven’t begun to migrate yet and are still in the winter yards.
“If the snow remains persistent, I would expect it will start taking its toll on the deer,” Jentoft said. “It would have been a lot tougher on the deer if winter started earlier. We were halfway through winter before we got deep snows.”
The northern Lower Peninsula in the Gaylord area is having an average winter, according to biologist Brian Mastenbrook. He reports some fawns getting a little fuzzy-faced, but winter is losing its grip there quickly.
“We only have about 10 to 12 inches of snow left and deer can be out and about and are moving around,” Mastenbrook said. “Some areas are opening up.”
The deep snows have biologists rethinking the number of doe permits that will be available in some areas.
U.P. biologists also were somewhat concerned about ruffed grouse due to the hard-pack snow that won’t allow them to make snow burrows. Snow burrows protect the birds from cold and predation.