Family Planning Reaches the Forest

To city dwellers, wild deer are perhaps the ultimate symbol of bucolic country life. But for many who live in the country and the suburbs, the animals are little better than rats with hooves, pests that voraciously eat gardens and crops, collide with cars and play host to ticks that carry Lyme disease. From a turn-of-the-century low of 500,000, white-tailed deer in the continental U.S. have rebounded to a population of 25 million -- about as many as there were before hunting, land-clearing Europeans colonized America -- and that is just too many to coexist comfortably with modern society. Still, simply killing off the excess raises questions of safety and ethics, especially in the suburbs.

Now researchers working with the Humane Society of the U.S. are trying a kinder, gentler approach: birth control. Led by Jay Kirkpatrick, a biologist at Eastern Montana College, they are rounding up wild does at the National Zoo's research center in Front Royal, Virginia, and inoculating them with what amounts to an antipregnancy vaccine. Developed by Kirkpatrick and two other scientists, the technique, known as immunocontraception, involves injecting a protein extracted from the reproductive system of a pig. In making antibodies to attack the foreign pig protein, the deer's immune system also attacks the doe's own, very similar protein. The result is temporary sterility.

Immunocontraception has already been field-tested successfully with wild horses on Assateague Island, off Maryland. If this and other planned tests work equally well, the vaccine could become the method of choice for controlling booming deer populations. It could even, in theory, be used as a one-shot, long-lasting human contraceptive as well.