Winter will take its toll on wildlife if tough conditions persist

So, just how bad is this winter so far?

For context, I checked out the Winter Severity Index, a measure the Minnesota Department of Natural Resources has used since the winter of 1988-89 to gauge conditions.

At this point, conditions aren't real bad, based on the index, at least. But they're getting worse fast, and there's lots of winter left. The next two months will be critical to the fate of deer, pheasants, grouse and other wildlife.

That's also true in North Dakota, which is enduring its third consecutive winter of heavy snowfall across the state. Barring a major break in the weather, hunters could feel the impact next fall.

And not for the better.

"Animals definitely could use a reprieve," Randy Kreil, wildlife division chief for the North Dakota Game and Fish Department in Bismarck, said in a news release earlier this week. "They are not as resilient as they were in the beginning of winter. The longer winter drags on, the greater the impact to wildlife populations and next fall's hunting opportunities."

That reality also will factor into the Winter Severity Index, which the DNR calculates by adding the number of days with temperatures colder than 0 degrees F and the number of days the snow depth exceeds 15 inches. As the DNR explains on its website, a day with a temperature of 5 below zero and 20 inches of snow on the ground would get an index of two.

That number, of course, tends to increase daily as winter progresses. The higher the number, the more severe the winter: An index less than 100 is considered mild, anything from 101 to 180 falls into the moderate category and an index of 180 or higher is considered severe.

So far, all of the sites in northern Minnesota fall into the mild category -- no surprise, considering February is just getting started. Updated every two weeks, the index Jan. 23 was 41 at Thief Lake Wildlife Management Area (up from 22 last year), 56 in Bemidji (23 last year), 61 at Red Lake WMA (26 last year) and 62 at Roseau River WMA (28 last year).

Poplar Lake, located along the Gunflint Trail in northeastern Minnesota, recorded the state's highest WSI reading to date at 89, compared with 29 in 2010.

Still, wildlife in northern Minnesota could be in for a rough time if last winter is any indication. The WSI might have been lower last year at this time, but by the end of April, the index had reached 156 at Red Lake WMA and 183 at Tower in northeastern Minnesota.

The same thing could happen this year if the snow and cold persist.

Already, there have been troublesome signs in North Dakota. Kreil said the Game and Fish Department has received reports of pheasant losses but the extent is unknown.

"For the most part, birds were able to adapt the past two winters under similar conditions," he said. "But then again, good nesting habitat in spring allowed them to rebound. With the continued loss of Conservation Reserve Program acres, their ability to rebound could be impaired."

The Game and Fish Department also has documented about 25 cases of deer dying from "grain overload," which occurs when deer switch from their natural diet to foods such as corn or other grains. Basically, their digestive systems can't handle starch, and even 1 to 2 quarts of corn or other grain can kill a deer in 48 to 72 hours.

In yet another sign of winter's impact, Game and Fish is working with about 200 livestock producers to protect stored feed supplies. That's similar to last year but far below the winter of 1996-'97, when the department worked with more than 1,000 producers on depredation issues.

Winter's bad, in other words, but it could be worse.

On both sides of the Red, there are a lot of "ifs" to the eventual severity and impact of this winter. And for wildlife living along the river, the spring flooding that now appears inevitable likely will present additional challenges.

"A mild February and March is much needed, and if we get a break we will see the benefits next fall," Kreil said. "If not, then hunters will need to adjust their expectations in 2011."

At this point, I'm betting on the latter. Stay tuned.

Dokken reports on outdoors. Reach him at (701) 780-1148; (800) 477-6572, ext. 148; or send e-mail to bdokken@gfherald.com .