BANGOR, Maine — For those of us left plowing and shoveling, the snowstorm that dropped more than 20 inches of snow on much of Maine Tuesday and Wednesday has been a bit frustrating.
For critters that live in the woods, some late-winter storms can be life-threatening. Luckily, however, the state’s deer biologist says this most recent storm shouldn’t prove too troublesome to the state’s whitetail population.
“We’ve had a really mild February for the most part, so I think a big storm coming after all that mildness is not going to be that big a deal for deer,” said Nathan Bieber of the Maine Department of Inland Fisheries and Wildlife.
Bieber explained that “winter severity” isn’t a mere guess for state biologists. Instead, biologists monitor conditions around Maine for 20 weeks each winter, from December through early April, in order to understand how severe the winters are for deer, and to quantify those conditions.
“We come up with a monthly winter severity number that comes from an equation that incorporates snow depth and temperature,” Bieber said. “It relates back to how deer are affected, so the higher the winter severity number, presumably the more difficult the winter is for the deer.”
That index is influenced by several variables.
“It’s how much snow is there, but we also measure ‘sinking depth,’ how far the deer sink [into the snow]. That doesn’t directly describe what the snow is like, but it gives you kind of a basic idea,” Bieber said. “If it’s really powdery, they’re going to sink way down. If there’s a crust on top, they’re not going to sink very far.”
And the less the deer sink, the less energy they have to expend to move around and find the limited food that’s on the landscape during the winter.
Temperature also plays a role, Bieber said, because the colder it is, the more energy the deer have to expend just to keep their own body temperature at the desired level.
“So far [the winter] has been more severe than the last two years,” Bieber said. “I would estimate by the end of the season the winter severity index will be higher than the last two years, but it has still been a pretty mild to moderate year.”
With a state the size of Maine, the conditions are not typically uniform from north to south. Bieber said that at a monitoring site in Orrington, conditions are vastly different than they are in Aroostook County, but in each case, the deer seem to be faring relatively well.
“Right now at Fields Pond [in Orrington], we’ve got a little more than a foot [of snow] in the softwoods and deer are just moving freely through that with no problem,” Bieber said on Tuesday, before the snow started flying. “Up north where you’ve got two-plus feet of snow, they start establishing trail networks and rather than moving all over, they’re just staying on those trails most of the time.”
Bieber explained that deer have a hard time finding suitable food during a typical winter, and during that crucial 20-week period, they’re trying to maintain their body weights as much as they can, hoping to survive until spring.
A late-season snowstorm can compromise a deer’s survival because moving through heavy drifts might burn energy the deer simply doesn’t have.
“Generally speaking, a late-season storm is going to be more difficult on deer,” Bieber said. “They are already very physically stressed and their body reserves are starting to dwindle, so it is going to hit them harder, say, than a January or December storm.”
But there’s an important reason why this recent storm isn’t likely to cause much distress in the herd, Bieber said: Viewed as a whole, winter hasn’t been too bad at all.
“This year in southern Maine, at least, we have had the blessing of all these open fields in all of February and March,” he said. “The deer have had some feeding opportunities that they wouldn’t normally have. So hopefully a late-season storm like this won’t be as impactful on them and they’ve been able to boost reserves a little by feeding in these open fields.”
Bieber counts the Bangor area among those “southern” locations with plenty of open fields, and said he’s been receiving phone calls from people who are reporting historically unprecedented numbers of deer feeding in their fields.
That added energy will help the deer deal with this storm, and any others, potentially.
“It’s not pleasant for deer, but they’ve been dealing with it for thousands of years,” Bieber said.