Effectiveness of modifying existing fences to deter deer and elk from crops and high-value pastures

Abstract

Big game can damage crops and compete with livestock for valuable forage. Ranchers have reported their tolerance for big game would increase if the animals could be prevented from using key areas critical for livestock use. Likewise, some farmers have high value areas and crops that must be protected. Fences provide the most consistent long term control compared to other deterrent methods, but are costly to erect. Traditional complete construction of game fences cost more than $9,000 per kilometer for materials. Costs of erecting deer proof fencing can be greatly reduced if an existing fence is modified instead of being replaced entirely. The objective of this study was to investigate the possibility of modifying existing fences to prohibit deer (Odocoileus spp.) and elk (Cervus elaphus) crossings. Forty exclosures were constructed to test 4 different fence modifications across southwest Montana. Exclosures were baited and monitored for two winters to determine how well they detered ungulate crossings. Results indicate effective modifications can be made to existing fences for $827 - $2187 per kilometer for materials. Different designs proved to have varying levels of effectiveness, with 1.8 m woven wire being 100% effective. These fences are a cost-effective way to fence out wildlife in many high-value areas where traditional fences are not practical. If farmers and ranchers can keep big game out of important foraging areas, their tolerance for these animals on the rest of their property may increase as depredation losses decrease.