Deer hunters as ecologists

Deer-hunting season is upon us again, and hunters around the country are packing their guns and heading for the woods.

It may seem ironic that in this time of loss of biodiversity, hundreds of thousands of people undertake to shoot deer for sport and food. But while I come to this issue from an ecological perspective, and I don't hunt, I would argue that the No. 1 wildlife issue in the Eastern United States is a gross overabundance of deer that is actually threatening the ecosystem, not to mention posing a serious hazard to motorists and farmers.

Brian Murphy, executive director of the Quality Deer Management Association (www.qdma.org), says the white-tailed deer range extends from Texas to Maine and west to Minnesota, a sort of backwards "C." Within that area live about 32 million deer. Of those, 1 million to 1.5 million are involved each year with deer-vehicle collisions.

How did the deer population skyrocket to the point of throwing our ecology so far out of balance? The answer in Pennsylvania is virtually identical to that of West Virginia and virtually all of New England. During the 17th, 18th, and early 19th centuries, much of the Pennsylvania forest was cut for wood and farming. By the late 1800s, narrow-gauge railroads pushed up ravines and creek beds throughout most of the state. Then, by 1900 the land was cleared, ravaged by fires that burned the remaining brush.

Today, with few exceptions, Eastern forests are second-growth, consisting of what grew back naturally after this period of human expansion. The most important impact has come from the loss of predators at the top of the food chain: the wolf and mountain lion. Those predators controlled the deer population.

In Pennsylvania, there are so many deer in the forests, fields, roads, and suburbs that they cause at least $300 million in damage each year. About $100 million of that is done to crops - and this in a state where agriculture is still the No. 1 revenue source. Some 45,000 deer are killed on state highways each year, doing another $100 million in damage to cars and drivers. And another $100 million of damage is done to private and state forests, which is where the problem is most acute.

Deer populations are so thick in some areas that they are entirely preventing the regrowth of saplings. Rare and famous old-growth forest areas such as Cook Forest State Park consist almost entirely of mature trees, with no new growth coming along to replace those giants that eventually fall from old age.

But perhaps more threatening is the fact that the deer are also eating the understory (where migratory songbirds nest), the wildflowers, and even the grasses. The forest is turning into a virtual species desert. There are areas such as Valley Forge National Park where there are more than 500 deer per square mile! While this is a uniquely high density, it is not uncommon to have more than 30 deer per square mile - a density which is beyond a sustainable level.

The forest is dying at this density, and its species composition is changing radically. Meanwhile, winters have been quite mild recently and the food supply is virtually infinite (think of all the cornfields, and consider how much additional fodder is supplied along edges of field and newly cleared forests). Natural predators are gone. The only thing left that is likely to make a difference in the deer population is hunting.

But what's the soundest approach? We posed this question at a conference last fall, attended by people with many interests from the Eastern US - hunters, farmers, state hunting and game regulators, native Americans, conservationists, and others. I was one of the organizers of that conference (see http://pa. audubon.org/DCP.htm for proceedings). One thing we could all agree on is that changing our approach to deer management is in the interests of all these parties, some of which have viewed their interests as being in conflict.

Now more than ever, it's time for Americans of all stripes to rethink our approach to managing deer populations. We need to develop an approach to deer management that's based on sound science and compassion for the animals and environment.

Bryon Shissler, a wildlife biologist, says state game commissions have historically approached deer hunting as if deer were an agricultural resource to be "harvested" by hunters. To a degree, this is true. What's sorely missing from hunting policy is a scientific understanding of the larger ecological environment in which deer live - of what levels of deer population are acceptable and beneficial to the environment, and at what point they cross the line. On the other side, some nature lovers who would never hunt consider the practice barbaric and, in the name of compasssion, oppose the practice altogether.

Some people advocate a "kinder and gentler" solution than hunting, such as deer contraception. But the reality is that deer contraception in the wild has no politically viable funding source, which renders it a non-option for a million-plus deer herd. Can you imagine the cost of trapping and inoculating every female deer in the herd, perhaps twice each year, and keeping track of all that? Hunting is the only way to control the deer herd in the short run, and perhaps in the long run.

I submit that the most scientifically sound and compassionate direction is for policymakers to change their approach to game management from an "agricultural" perspective to an "ecological balance" perspective, in which hunters take the place of predators and keep the ecosystem in balance.

It is a sort of "strange bedfellows" experience that hunters are actually the key to preservation of so many values we hold concerning the outdoors of the Eastern US.

It is frightening to face the future of the forest in Pennsylvania, seeing species extirpation going on at such a rapid pace. The state game commission is working with a new sense of urgency to implement the plans of its advisers and staff to bring the deer herd under control. These are responsibilities society does not necessarily welcome, but decisions made centuries ago leave us few options.

Donald L. Gibbon, a geologist with 35 years of field experience, is a consultant to the Pennsylvania Bureau of Forestry.

(c) Copyright 2000. The Christian Science Publishing Society