There is hardly a topic in the letters to the editor of our local paper, The Rivertowns Enterprise, that is more emotional and sensitive than deer control. Local citizens who believe that the deer population should be reduced usually cite three reasons, that deer destroy ornamental plantings, cause traffic accidents, and spread Lyme disease.
These are all serious concerns but, as I’ve learned recently, there is a far more significant reason: Deer are destroying the understory of our forests and wooded areas.
In the fragile ecosystems of the woodlands that surround and weave through our suburban areas the deer are eating and/or have destroyed the lowest growing plants and shrubs, including the tree seedlings. This is upsetting the balance of nature—of animal, insect and bird life—and is preventing regeneration of the forests, which are responsible through the carbon cycle for creating the very air we breathe. According to the U.S. Department of Agriculture, one acre of forest absorbs six tons of carbon dioxide annually and puts out four tons of oxygen. This is enough to meet the needs of 18 people.
Thus, even if the deer could be kept out of our yards with fences and sprays; even if everyone planted only “deer-proof” species; even if there were no traffic accidents or cases of Lyme disease, deer herds in the woods—like those we see along the Saw Mill Parkway, on Mountain Road, and throughout the Rivertowns—are destructive to our region and our planet.
Carolyn Summers, a landscape architect and adjunct professor at Westchester Community College, is a local expert on biodiversity. She writes in Designing Gardens with Flora of the American East, “Instead of a sustainable number, perhaps ten or twenty deer per square mile, surveys are revealing population densities in the hundreds. Deer are eating themselves out of house and home. In the process, they are leaving little or nothing for other forms of wildlife, including the plants that support us all.” In a recent lecture I attended, she stated that almost all butterflies require indigenous flora—the plants the deer are destroying—to reproduce. In turn, baby birds can only exist on insect larvae. Decimated foliage means fewer beneficial insects and reduced bird populations.
Dr. Doug Tallamy, professor and chair of entomology and wildlife ecology at the University of Delaware, and author of Bringing Nature Home, agrees: “The deer are above their carrying capacity—that is, the herds are larger than the land can support—because we have killed all their predators in our area. We have also created their favorite edge habitat, our gardens. In many places, the only plants the deer have left in our forest understory are invasive and unpalatable species. Our forests may appear to be healthy, but there is no recruitment; that is, the next generation of trees is being destroyed.”
In a paper entitled “Ecological Impacts of Deer Overabundance,” four professors at the University of Wisconsin and Université Laval, Quebec, state: “By foraging selectively, deer affect the growth and survival of many herb, shrub and tree species. Cascading effects on other species extend to insects, birds, and other mammals. In forests, sustained over-browsing reduces plant cover and diversity, alters nutrient and carbon cycling. These states are difficult to reverse.”
Solutions are tough to come by. Contraception has been proposed, but there is no evidence that it works on a large scale. Says Prof. Tallamy: “The only place that I know contraception has worked—meaning the herd is no longer growing—is Fire Island in New York. The experiment was in a small area where they could dart all the deer with contraceptives. It has failed everywhere else it was tried. The deer have to be darted repeatedly, and it’s way too expensive. Experts will tell you that sharpshooters are the only thing we have right now.”
The Fairfield Country, CT, Municipal Deer Management Alliance maintains a comprehensive website with facts, studies, and articles. All evidence seems to point to the fact that thinking globally may mean looking beyond our own backyards and making painful decisions at the local level. Very few people, especially in communities like ours, can abide the thought of sharpshooters felling deer with bow and arrow. I live at the intersection of Whitetail Road and Deertrack Lane, which sounds idyllic. But last night I turned into my driveway and almost hit a deer. The situation has gotten so out of hand, and the consequences so dire, what choice do we have?