By Jack Kloepfer

Years ago I put that question to a respected Yellowstone wildlife biologist and former Wisconsin state game manager. He responded that human hunting will never control white-tailed deer populations. That response sent me on a quest for knowledge and answers to the ever-expanding white-tailed deer population in North America. I soon found out trying to obtain unbiased and objective info from game managers and sport hunters was futile if not downright sacrilegious. Over the past ten years I’ve gathered information by working as a volunteer on wildlife conservation projects and deer census in North America and South America, talking to field biologists and reviewing findings of wildlife studies. Additionally, I found a good deal of useful information in the book “The American Hunting Myth” by Ron Baker. Lastly, I analyzed principles of basic wildlife biology. The following is a summary of my findings and conclusion.


Many hunters, to their credit, honestly believe they are practicing conservation by “thinning the herd”, as they call it. After all when you kill something it no longer exists, right?


Yes there is an immediate reduction of animals but what about the long-term reproduction response to hunting?

(Photo by Kimberly Duke – Kimberly was shocked to find a killing field of deer after hunting started. This allowed hunters to kill more. The poor deer below were hacked apart and left to rot, so hunters could overkill.)

Why do states like Minnesota, Wisconsin, Michigan, PA, GA and TX which have the most hunters also have the most deer? Why have deer populations in these as well as other heavily hunted states steadily risen in the past three or four decades? More importantly, what are the environmental consequences of high deer populations? The answer my Yellowstone wildlife biologist friend gave me soon became clear because sport hunting is simply not supposed to reduce deer populations. It is a business. Why kill the goose that laid the golden egg? Game managers are not going to manage away their livelihood. Rather than reduce hunting, game management will seek to expand hunter opportunities by extending seasons and opening new areas to hunting. Game management is designed to insure a bumper crop of replacement “targets” each fall. Lots of “targets” means lots of hunters. Lots of hunters mean revenue for the state and federal wildlife management coffers. Consequently, deer populations are tied to and explicitly managed by permits. That is the nuts and bolts of deer management in America. The problem with the agenda is that it is working too well. Many game managers will freely admit that white-tailed deer exceed prudent carrying capacity in many areas. This is often used as a ploy to promote hunting, but often when we tamper with nature it can backfire.


Hunting and management policies have created an overabundance of deer by the manipulation of deer biology. White-tailed deer have a natural sex ratio that is approximately 51% male. This is one of nature’s important control mechanisms. Deer are polygamous, meaning males will impregnate multiple mates. When fewer doe permits are issued, more females survive to breed. The higher percentage of females in a herd compromises this important control mechanism.

After the availability of a mate, the primary factor of reproduction of wildlife is the availability of food. Historically, game management has maximized deer habitat by the slash and burn technique. This promotes the vigorous growth of new shoots of grasses which deer love. In the past, some state game departments have actually planted wild corn patches to encourage deer populations. Winter feeding programs have also been used to promote deer. I have witnessed both planting and winter feeding programs in the 1970’s in McHenry City, IL. Human intervention with the natural process is a contributing factor to deer abundance. Weather, primarily severe winters and drought can play an important natural check of deer.

A basic factor of reproduction of any organism is the principle of overcompensation for losses. Hunting creates a sudden drop in herd density which will activate the overcompensation mechanisms in deer. Deer will overcompensate to hunting stress by having more twins and triplets causing an explosion of fawns each spring. Reproduction rates are also encouraged by the increase of space and food available to the survivors of the hunt. Conversely, in non-hunted environments reproduction rates would not be stimulated causing fewer females to become pregnant and single births become the norm.

A study in the Shenandoah National Park has shown that a high number of large herbivores, like deer, have negative effects on ecosystems by crowding out smaller animals ad reducing biodiversity. Studies in the northwestern U.S. are showing that white-

tailed deer have become so numerous in some areas they are crowding out mule deer. While “crowding out” is a subtle phenomenon, it is a very real danger to biodiversity and long-term well being of our biosphere.


Some pro-hunting advocates will promote doe hunting only to control populations. In practice this has rarely worked. Although a few suburban hunters would shoot does, most deer hunters disdain killing females. Killing does contradicts the most sacred white-tailed deer hunting doctrine of bagging the largest buck with the largest rack. Few hunters would pay a taxidermist good money to mount a doe head above their fireplace. Mistakes as well can be made. Often in the field it is not easy to determine whether you are shooting a doe or a buck. Some bucks are antlerless. Often bucks with small “spikes” are taken for does. For some urban hunters, it is difficult to determine the difference between a cow and a deer.

Additionally deer, in search for mates and food, will “fill-in” or migrate to areas which have been “thinned.” Radio-collared deer have been known to migrate 20 miles.

Many proponents of hunting attempt to rationalize sport hunting by saying human hunting takes the place of natural predators. While it is true many areas of our country lack natural predators, which is due to over hunting and government predator control programs, it has never been conclusively proven that predators control ungulate populations. In fact, prey numbers may have a greater influence on predator numbers. This is commonly referred to as the bottom to top control mechanism. The 30-year study of moose and wolf population dynamics show that wolf populations may actually be driven by moose populations. Carcass studies in the Yellowstone wolf project show the average wolf-killed cow elk is 14 years old, far past the prime breeding ages of 2-9 years. These studies, as well as others, clearly show predators have little effect on ungulate populations.

Predators will primarily kill the older, injured and sick animals. Recently a Yellowstone wildlife biologist witnessed a wolf make three unsuccessful charges into an elk herd. After the third charge, the exhausted wolf stood panting as three large bull elk charged from the herd surrounded the hapless wolf and attacked! The battered wolf narrowly escaped with his life.

The theory that the presence of predators markedly reduces ungulate populations has little scientific basis. Before human intervention carnivores and herbivores evolved for eons in a life-sustaining harmonious relationship.


I believe the reduction of hunting stress, allowing natural population checks like natural sex ratio, normal birth rate, weather and disease, a natural predator/prey interaction, as well as immunocontraception in selected sites would be sufficient to maintain a reasonably stable and environmentally sound deer population. The immunocontraception program – the administration of a contraceptive vaccine by darting – developed by Jay Kirkpatrick, Ph.D., of the HSUS has proven to be 90-95% effective in reducing pregnancies in wild horses. The vaccine is currently being adapted for use in deer. Immunocontraception holds great promise for use in island populations of deer, residing in urban nature centers and conservation sites where hunting would be ineffective, inappropriate and dangerous.

It would be environmentally beneficial to scale back hunting to a level which would not increase reproduction rates, end control of predators, and institute a management philosophy based on science and restoring ecosystems.

It is said that everything in America is driven by politics and money, and game management is no exception. Wildlife policies are primarily established for the benefit of special interest groups, such as sport hunters, with little input from the general public. This is done at great cost to predators and non-game species.

The good news is that there is a growing appreciation for wildlife, and an increase in environmental consciousness. This ethical and environmental awareness portends a bleak future for sport hunting in America. I believe the idea of using sport hunting as a conservation tool will become as obsolete as using the Pony Express to deliver mail. Hopefully, the changes will not come too late. Nineteenth Century philosopher Arthur Schopenhauer’s concept of the three phrases of truth are: First it is ridiculed. Second it is violently opposed. Finally it is accepted as being self-evident.


Contact Us

Committee to Abolish Sport Hunting / C.A.S.H.
P.O. Box 562
New Paltz, NY 12561