Text and Photos by Charles J. Alsheimer
Much has been written about wintering whitetails — everything from fawn mortality to how deer populations migrate. And certainly, great work has been done to help deer hunters understand how winter affects deer in the North. However, because hunting pressure, predation and severe winters make it difficult for bucks to reach old age, little has been written about what it takes for an old buck to survive a Northern winter.
For those of us who raise whitetails, a buck isn’t considered old until it reaches about 10 years of age. That’s when a buck’s body and antlers begin to show a significant decline. But that isn’t the real world. In a wild, free-ranging whitetail population, most knowledgeable whitetail enthusiasts consider any buck older than 6 or 7 to be old.
By the time a buck has survived to the ripe age of 6, he has dodged nearly every thing life has thrown at him. He’s been chased and hunted by man and beast, endured the stress of summer insect populations, fought numerous times for breeding rights, and struggled through deep snow and cold in search of food. By the time he’s reached old age he has experienced a lot and learned what it takes to survive when the temperature drops and snow begins to fall. Still, his survival is far from guaranteed.
In order to survive winter, an old buck must have several things going for him: good food, adequate cover, minimal stress, health and a winter that is reasonably mild.
Food is critical. An older buck must have above average food sources to survive the rigors of a Northern winter. If he enters December with inadequate fat reserves, it will be tough for him to survive.
Cover is also essential. To survive winter, a buck must keep his core body temperature at a sustainable level. Consequently, shelter is a critical component for winter survival. During the dead of winter, the temperature in a conifer forest is roughly 10 degrees warmer than open hardwoods. A buck needs to know where these locations are and bed there when the going gets tough.
Stress is a factor as well. As a deer ages, its ability to handle stress decreases. One of the greatest stresses for an old buck is an overpopulation of deer. If you add to this other stressors — like swarming insects in summer, food shortages (because of too many deer), the rigors of the rut, or having to breed too many does — by the time winter arrives, an old buck might be too stressed to survive.
Health and Mother Nature play a part, too. Often older bucks enter December exhausted, and in many cases, wounded from the fights they’ve encountered during the rut. These factors, as well as overall health, play a major role in a buck’s ability to survive a winter.
One thing deer cannot control is winter’s severity. Some areas of the North go years without a severe winter, making it easier for older bucks to survive. Then, the tide turns on them and their corner of the world gets hit with several bad winters in a row. When this happens, the young, old and weak are the first to die.
It might seem like the odds are stacked against an old buck making it through winter. However, whitetails are hardy, adaptable creatures. During winter, a whitetail’s metabolic rate drops, decreasing its need for food. I’ve studied the food consumption of our research facility’s deer month by month for the past 10 years. I’ve found that even if our deer are provided all the food they want, they only consume about half as much food in January and February as other months.
In addition, the fully mature bucks consume about 10 percent less food than 1- to 4-year-old bucks during January and February.
With less food needed for survival, mature bucks bed more than younger bucks during winter. It’s not uncommon for a fully mature buck to bed 90 percent of the time when winter becomes harsh. This enables old bucks to conserve energy and maintain adequate body temperatures.
Age also allows wild, free-ranging bucks to know where their zip code needs to be when winter’s snows begin piling up. Because age has enabled them to experience several winters, they know south-facing slopes are warmer on sunny winter days. They also know thick conifer swamps will be warmer at night.
So, although survival might be more difficult for stressed older bucks, these warriors also know that to survive winter they must eat right and bed a lot to gain an edge when the wolf of winter comes knocking at their door.
— Charles Alsheimer is Deer & Deer Hunting’s contributing editor of deer behavior.
References:
Archives