Fawn Harvesting—A Logical Alternative for Northern Range
(En anglais seulement)
By: John J. Ozoga
The quality of winter habitat and severity of winter weather are the most important factors regulating deer populations across much of the northern portions of the whitetail's range. This is particularly true in the Great Lakes Region north of the 43rd parallel (roughly from central New York, through north–central Michigan, to central Wisconsin), where mild winters allow deer populations to build up to unusually high numbers, only to crash later, during the next severe winter. Such “boom and bust” cycles probably have prevailed ever since whitetails extended their range northward behind receding glaciers.
Young of the year—still referred to as fawns in winter—are the pawns squandered in nature's wicked game of winter survival. During good times, fawns flourish and represent a high percentage of the population. However, during harsh winters, they are the first to die—sometimes by the hundreds of thousands.
Why Harvest Fawns?
There are some good biological reasons why hunters could and, in some situations, should harvest more fawns on extreme northern ranges:
- Fawns generally represent the most numerous single age class in the population. More fawns typically survive to weaning age than are needed to replace adult mortality.
- Fawns contribute little or nothing in the way of reproduction the following year. So their harvest has little impact on annual recruitment rates.
- Fawns are always under–represented in the annual harvest. Given a choice, hunters generally harvest an antlered buck or a doe, instead of a small–bodied fawn.
- Fawns are the most likely to die during harsh winters. Even during years of high reproductive success, there is no guarantee that a high proportion of the annual fawn crop will survive their first winter and be available for harvest as yearlings.
Being Small—Good or Bad?
Fawns typically are smaller than adults, which presents certain advantages as well as disadvantages. Cornell University scientist Dr. Aaron Moen points out that fawns entering the winter at below–average weights have certain laws operating against their chances of survival. Based on Moen's calculations, “More heat is lost by convection (air movement) from a square meter of surface of a small deer than from a square meter of surface of a large deer.”
The critical body weight for fawns lies somewhere between 77 and 88 pounds. Animals below this range lose considerably more body heat, and are less likely to survive extended periods of cold weather. By comparison, larger deer are more efficient in terms of energy conservation. In the South, small fawns often are the result of late births. These fawns may actually experience a metabolic advantage because of their lower food requirements and survive in high numbers where mild winters are the norm.
In contrast, small fawns in the North are more commonly the product of poor summer and autumn nutrition. For them, poor nutrition during the snow–free months is invariably followed by extremely stressful and impoverished food conditions during winter. Few of these stunted and comparatively lean fawns are likely to survive such hardship.
The recent winters of 1995–96 and 1996–97 will long be remembered as real deer killers throughout the Upper Great Lakes region. During those two particularly tough winters, an estimated 310,000 whitetails died in Upper Michigan alone. Roughly half of them were fawns. Even during moderate winters, fawns represent 80–90 percent of the total winter mortality. When coupled with browse–depleted winter range, the loss still can be sizable in high–density deer herds containing many malnourished fawns. In Upper Michigan, for example, the annual death toll of whitetails during the mild winters of the late 1980s and early 1990s matched or exceeded the area's legal rifle harvest, which ranged between 40,000–55,000 deer, annually. Ironically, such winter mortality occurs largely during late winter and early spring—only after each deer already has consumed a large quantity of valuable browse and further degraded the winter habitat.
Fawn Tagging Studies
Studies conducted in Upper Michigan's Petrel Grade Deer Yard revealed high natural mortality of fawns during their first winter. Although fawns represented only about 30 percent of the yarding herd, they accounted for about 60 percent of the total mortality.
Of 145 male fawns we live–trapped, tagged, and released in the yard, only 47 (32.4 percent) were ever reportedly killed by hunters. We had no information on female fawns because of very limited antlerless harvesting in the area. More recently, similar recovery results were found when biologists examined more than 250 male fawn tagging records from various deer yards throughout central Upper Michigan. In fact, the return rate of tagged animals was an identical 32 percent. Certainly, not all tagged animals shot by hunters are reported. And, some bucks survive their first winter only to succumb later to other mortality factors. Nonetheless, the available evidence strongly suggests that, on average, only about half of all fawns survive their first winter in Upper Michigan.
Even during very mild winters, studies conducted by Dr. Timothy VanDeelen revealed comparatively high overwinter fawn death rates in Upper Michigan's Whitefish Deer Yard. During three mild winters (1992, 1993, and 1994), 32 percent of buck fawns and 28 percent of doe fawns fitted with radiocollars died from natural causes during their first winter.
In northern Wisconsin, Dr. Orrin Rongstad also found overwinter fawn mortality rates highly variable. During some very mild winters none of his radio–collared fawns died; whereas, as many as 44 percent died during some severe winters.
The “Bambi’ Complex
From a management standpoint, it is unfortunate we call them "fawns." Even when they are seven or eight months old, and even when some are sexually mature, they are still fawns in the eyes of most wildlife biologists, educated hunters, and the general public. Educated hunters typically distinguish deer as being fawns, yearlings, or adults during the autumn hunt. On the other hand, hunters who know very little about deer biology, recognize only bucks and does. For them, female fawns become “small does,” whereas male fawns are “button bucks” or “knobby bucks.” Even knowledgeable hunters will resort to such terms to minimize criticism for shooting a fawn.
Regardless of their size, the term “fawn” has a certain stigma attached to it. The general public often envisions them as being innocent, spotted creatures hardly able to toddle on wobbly legs. Regardless of their size, to some, the term fawn is synonymous with “Bambi”—after all, who would want to shoot an innocent Bambi?
The idea that fawns could and should be selectively harvested on northern range is nothing new. In 1975, Dr. Orrin Rongstad issued a University of Wisconsin extension news release entitled, “Shoot Fawns to Help the Deer Herd.” In this release, Rongstad criticized hunters for not shooting more fawns, suggesting that starvation losses and waste would be reduced on northern range if hunters selectively shot more fawns. He added, “Because hunters with antlerless permits shoot larger animals, the ages of the animals hunters kill differ from the age structure of deer dying during a severe winter. So, killing a deer during the hunting season does not necessarily prevent one from starving during the winter.” In fact, Rongstad proposed that hunters who shoot a fawn should be rewarded in some way, not condemned. “They're helping the deer population,” he argued, “more so than hunters who kill larger, older animals instead.”
Despite the biological soundness of his proposal, Rongstad was blasted by the ecologically ignorant press for advocating such a revolutionary deer management strategy. Even some wildlife professionals slammed Rongstad, not on biological grounds, but for political reasons. The sentimental and emotional public just was not ready, neither were deer managers, who were more concerned with providing quantity instead of quality. Deer hunters, who were more concerned with trophies on the wall or large quantities of venison in the freezer, also were not ready.
Conclusions and Management Implications
As with many aspects of deer management, the application of this research depends on your individual situation and management objectives. If your deer population is at or near the carrying capacity of the habitat (i.e., too many deer), and your goal is to reduce the population, then harvesting adult does, rather than doe fawns, is advised. This reduces the number of breeding–age does and, following the additional natural fawn mortality during winter, the reduction in the population will be maximized.
In contrast, if your population is below the carrying capacity of the habitat, and herd stabilization is your goal, then harvesting fawns, particularly doe fawns, is recommended. Such a harvest mimics natural mortality, makes wise use of a vulnerable and precarious surplus, and has little impact upon the size of next year’s deer herd. This also would lessen browsing pressure in critically important deer yards.
The harvesting of buck fawns is somewhat more complicated. Given that most practitioners of Quality Deer Management attempt to maximize the number of mature bucks in a population, the harvest of buck fawns is generally not recommended. However, in extreme northern ranges, many buck fawns will succumb to natural mortality even when protected from legal harvest. As such, protecting buck fawns in these areas will have minimal effects during years of extreme winters. However, during mild winters, protecting buck fawns may increase the number that survive the winter and enter the population the following year as yearlings. In either case, a buck fawn is far more "expendable" than a yearling buck if a harvest decision between the two must be made.
In conclusion, harvesting fawns on extreme northern ranges is a logical alternative to massive winter deer mortality and further deer yard degradation. It could be safely implemented even in areas of low deer numbers where no antlerless deer hunting currently exists. Surprisingly, neither educated hunters nor trained biologists have advocated this harvesting strategy—even in the face of recent massive winter dieoffs. I cannot help but wonder if the day will ever come when scientific reasoning, instead of human emotions, determines deer management direction?
Mr. John Ozoga is a former Wildlife Research Biologist for the Michigan Department of Natural Resources. He spent more than 30 years conducting deer research at Upper Michigan’s Cusino Wildlife Research Station. He now devotes much of his time to consulting and popular writing and serves as Research Editor for Deer and Deer Hunting magazine.
Portions of this article were reprinted with the author’s permission from a previous article in Deer and Deer Hunting magazine.