Although a lot of snow has fallen across northern Minnesota since early February, the Winter Severity Index compiled by the Minnesota Department of Natural Resources remains below average, said Tom Rusch, DNR area wildlife manager at Tower.
“Winter severity, specifically snow depth and duration of snow cover, is the most critical factor affecting white-tailed deer survival in the northern forest,” Rusch said. “Deer movement is now heavily restricted, especially up in the border country. Deer are in heavy conifer cover. With restricted mobility, wolf predation will increase as the tables have now turned against deer. Until mid-February, deer had excellent mobility, and wolves were at a disadvantage, in all but the northern most parts of St Louis County.”
The winter of 2012-13 has abruptly changed since the last Winter Severity Index report in early February, Rusch said. More than 30 inches of snow has fallen in the last month in northern St Louis County, with three storms in the 6-inch-plus category. For northern forest whitetails, the going has gotten tougher. All snow measurement stations are currently over the 15-inch mark, one of the thresholds the DNR uses in computing its Winter Severity Index. The other threshold is the number of days when the temperature reaches zero or below.
As of March 12, snow depth readings were 24 inches at Greaney, 22 inches at Snowbank Lake near Ely, 20 inches in Tower and 18 inches in Eveleth.
“If winter and snow pack fade in late March, the 2013 fawn crop should still be a good one in most of northern St. Louis County,” Rusch said.