As we head into March, scenes like this (above photo) are now common, as well more than 50 percent of the bucks have shed their antlers in the upper Midwest. In other areas of the country, most bucks have shed their antlers by now. There were several cases of bucks shedding their antlers in January. I’m speculating off of years of experience here, but I’d attribute almost all of these cases to environmental stress on the deer herd.
A common question that we get here at Deer & Deer Hunting goes something like this:
“I’m guessing low stress and a mild winter helps bucks hold onto their antlers longer?”
In general, the answer to that question is a qualified “no.”
Low stress and good nutrition can prolong deer to hold their antlers, but not usually. Of course, nothing is absolute when it comes to whitetails. Interestingly, bucks will shed their antlers (we’re talking adult bucks here) nearly the same time every year. Charles Alsheimer has documented this phenomenon in Deer & Deer Hunting many times over the past 30+ years. When bucks get beyond 4 years old, Alsheimer said they will shed almost to the same date every year — give or take a day or two. Shedding is a genetic predisposition that way.
Now, during really severe winters, mostly during severe nutritional stress, bucks can and do shed their antlers earlier. The overall health of the individual animal plays a big role in these cases. But, all things being equal, an adult buck that sheds his antlers the last week of February this year will most likely shed during that same week for the rest of his life. Yearling bucks are a different story, as they have yet to reach maximum skeletal capacity.
What about deer health in winter?
During normal years, whitetails can withstand almost anything Mother Nature dishes out. Their breaking points, however, are deep winter snow depths and brutally cold temperatures. The 2013/2014 winter was a doozy in many Upper Midwest and Northeast states. This year’s weather has been harsh, but nothing close to what could be considered harsh on the deer herd in general.
Many decades ago, biologists in Minnesota and Wisconsin set out to learn more about winter’s wrath on the whitetail herd. During their studies, the researchers found a direct link between snow depth, wind-chill temperatures and winter dieoffs among whitetails. They also came up with a formula for predicting how bad any given winter would have on the deer herd. It’s called the “Winter Severity Index.” Here’s how it came to be, according to the Wisconsin Department of Natural Resources:
“Prior to 1975, Wisconsin did not have a formal procedure for measuring winter severity and predicting its impact on deer herds. Michigan had developed a severity index that used calorimeters to estimate a winter air-chill factor, and snow depth and sinking-depth measurements to estimate a snow-hazard factor (Verme 1968). The air-chill and snow-hazard factors were summed at the end of each week to derive a cumulative severity index. Ontario was using the Passmore-Hepburn Method, which also involved collecting relatively complex snow measurements (Passmore and Hepburn 1955). Our winter severity index (WSI) was developed after testing several procedures for quantifying winter conditions (Kohn 1975). It used the number of days with a minimum temperature of 0°F as a measure of winter air-chill, and the number of days with 18 inches of snow on the ground to estimate the snow hazard. Days when both conditions occurred are scored as 2. These are added together from 1 December through 30 April to obtain the WSI.”
Winters are considered “mild” if the calculated WSI is less than 50, “moderate” if it is between 50 and 80, “severe” if it is between 80 and 100, and “very severe” if the WSI exceeds 100.
As you can see, last year was bad. Really bad in some areas of northern Wisconsin. What about this year? Not so much. It’s been incredibly mild, based off the numbers so far:
Throw in one heavy snowfall in March (or even April) — and continued below-zero temps — and we’ll be looking at slight winter die-offs of last year’s fawns, older bucks and, in some cases, even mature does, but nothing to get too alarmed about.
Let’s just hope winter’s worse is already behind us and an early spring is in the cards.