Effectiveness of a Vertical 3-wire Electric Fence Modified with Attractants or Repellents as a Deer Exclosure

We conducted experiments with behavioral conditioning of white-tailed deer (Odocoileus virginianus) using verb 3-wire, electrified fencing modified with either an attractant or a repellent in order to test the idea that an attractant or repellent coupled with an electric shock, would be a more effective deterrent than a random shock or no shock at all. Exclosures measuring 6 x 6 m with 3 wires at heights of 50, 100, and 150 cm were established at 2 study sites in Tompkins County, New York. Each site contained 4 exclosures which were either nonelectrified (control), electrified, electrified with an attractant, or electrified with a deer repellent. We baited each exclosure with fresh apples to ensure visitation by deer. All exclosures were monitored daily to determine her visitation, disappearance of apples, and to measure fence voltage. Data from 116 days indicate that the electric fence with a repellent excluded deer most effectively. Deer penetrated this type of exclosure only once. Electricity and attractant ranked second, and electricity alone ranked third in effectiveness for excluding deer. The control was the least effective barrier (37 encroachments). Proc. East. Wildl. Damage Control Conf. 5:44-47. 1992 Increasing human populations, urbanization of rural areas, and increasing populations of white-tailed deer cause more frequent interactions between humans and deer. This increase in interactions corresponds with an increase in deer damage incurred by fruit growers, nurserymen, and other groups (McAninch and Fargione 1987). Damage and economic losses sustained by farmers (Hyngstrom and Craven 1988), orchardists (Phillips et al. 1987, Purdy et al. 1987), nursery growers (Sayre and Decker 1990), and even gardeners and ornamental plant owners (Sayre and Decker 1990) have brought about the need for improved deer control techniques. Little work has been done combining electric fencing with deerrepellentsorattractants. Separately, fencingandrepellents have been found to reduce damage, and perhaps together they have a synergistic effect. We hypothesize that the addition of a repellent to an electric fence would double the negative reinforcement for deer. The repellent itself may cause the deer to avoid the fence. However, if a deer does attempt to enter the fence and receives a shock, the combination of the repellent and the shock may clause the deer to recognize and avoid the fence in the future. Coupling the electric shock with an attractant, to ensure that the encroaching deer receives the shock, may also enhance fence effectiveness. Peanut butter was used as an attractant to encourage deer to touch the electric wires with sensitive parts of their bodies (i.e., their tongue or nose). This, we hypothesize, results in a sufficiently severe shock for deer, and would cause conditioned animals to avoid fenced areas in the future. The use of peanut butter has been found effective with single-wire fences exposed to light deer pressure (Kinsey 1976, Porter 1983, Hygnstrom and Craven 1988), and may therefore enhance the effectiveness of the 3-wire design. We report here on the testing of the 3-wire electric fence with attractants and with repellents to determine its effectiveness as a deer exclosure.