Editors Blog

Dan Schmidt: Can Brutally Cold Weather Affect When Bucks Shed Antlers?

This season's brutal cold temperatures are adding up quickly. The result: Stress on the deer herd, which means many bucks are losing their antlers more than a month earlier than normal. (photo courtesy of Michael Solberg)

This season’s brutal cold temperatures are adding up quickly. The result: Stress on the deer herd, which means many bucks are losing their antlers more than a month earlier than normal. (photo courtesy of Michael Solberg)

Can cold weather affect when bucks lose their antlers? Absolutely. It’s not common, but as seen here, it can happen when the days of below-zero temperatures start adding up. In fact, this is the fifth trail-cam photo I’ve seen this week of a buck that has already shed its antlers. 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.

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 bad news is this 2013/2014 winter is shaping up to be a doozy in many Upper Midwest and Northeast states.

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.

Wisconsin’s deer herd is not even near a critical juncture … yet, especially considering the fact that as of today (Jan. 2), only one small pocket of northern Wisconsin had snow depths of more than 12 inches (6 inches below the WSI requirement). However, the big caveat here has been the cold temperatures. Where I live, in Waupaca County (which, by the way, is too far south to be considered a candidate for WSI impacts), we have already experienced 16 days where temperatures have dipped below zero.

Throw in one heavy snowfall — and continued below-zero temps — and we’ll be looking at moderate to severe winter die-offs of last year’s fawns, older bucks and, in some cases, even mature does.

Let’s just hope winter’s worse is already behind us and an early spring is in the cards.

6 thoughts on “Dan Schmidt: Can Brutally Cold Weather Affect When Bucks Shed Antlers?

  1. D&DH Editor Dan Schmidt Post author

    This year has been quite the exception, hasn’t it? We haven’t had one like this, that I can recall anyway, since 1977. Going to take a toll on herds across the country, no doubt. -DS

  2. exaltedjbowtech

    Hi dan, as for brutal temps causing antlers to shed a month early i strongly disagree,,, its feb 27th and.i am located in north east ohio i have been shed hunting for over a month now and found 1 and in the past two weeks ive encountered 15 mature whitetails still holding antlers

  3. exaltedjbowtech

    Also dan another factor that is far from the truth is you claim brutal cold temps cause antlers to shed a month early well i have to disagree bud…..today is feb 27 im located in north east ohio I’ve been out shed hunting over a month so far and found 1 and in the last two weeks ive spotted over 15 mature deer still supporting both antlers .

  4. NWWI

    Dan-

    This couldnt be farther from the truth. Have you looked at the NOAA snow cover map online? A couple MILLION acres of Northern Wisconsin has between 20 and 50″ of snow on the ground right now. They have had 20″+ on the ground for 6 weeks or longer. I know because I havent been able to get into my Deer Camp in Douglas county because it too deep for my truck.

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