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Item Permeability of three-strand electric fences by black bears and grizzly bears(Montana State University - Bozeman, College of Agriculture, 2018) Johnson, Brittani Justine; Chairperson, Graduate Committee: Lance McNewElectric fencing has been used to deter bears in North America for several decades. Producers have turned to a design of a minimum of five-wire electric fence as their primary solution to reduce livestock depredation and to reduce raids of chicken houses and beeyards. However, these designs are expensive and reducing the number of wires used in a design to three wires would be beneficial. Scientific evaluations of the efficacy of three-wire electric fencing at deterring bears is lacking. In 2015 and 2016, I conducted a study in the Blackfoot Valley of Montana to evaluate the efficacy of rapid-deployment electric fencing designs in deterring bears from baited enclosures. Baited enclosures of two fencing configurations were established at 20 sites in the study area. Each enclosure was systematically energized and unenergized for 3-day periods; and passage into the enclosure was monitored with trail cameras to provide information on effectiveness and permeability. I recorded 134 visits by bears to fenced enclosures during the study seasons of 2015 and 2016. Of these visits, 78 occurred in 2015 and included 57 black bears and 21 grizzly bears. Fifty-six visits occurred in 2016, including 34 black bears and 22 grizzly bears. Black bears and grizzly bears were successful at passing the short fence 48% (95% CI: 32.0 -- 63.6) and 23% (5.0 -- 53.8) of the time, respectively, when it was not energized. When the short fence was energized, black bears were 7% (0.2 -- 33.9) successful in passing, whereas grizzly bears were successful in 25% (5.5 -- 57.2) of attempts. When not energized, both species successfully passed the tall fence design in 58% (95% CI: 27.7 -- 84.8) of attempts. Black bears and grizzly bears successfully entered energized enclosures with tall fences in 30% (95% CI: 13.2 -- 52.9) and 0% (95% CI: 0.0 -- 45.9) of attempts, respectively. Both fence types deterred bears from entering baited enclosures and all fences allowed less than perfect access when unenergized, suggesting that even minimalistic configurations of electric fences may act as barriers to black and grizzly bears. Further study evaluating the effects of rapidly increasing construction of electric fencing is needed to assess landscape level effects on bear movement and habitat selection.Item Effectiveness of modifying existing fences to deter deer and elk from crops and high-value pastures(Montana State University - Bozeman, College of Agriculture, 2006) Fenster, Randy Lee; Chairperson, Graduate Committee: James E. Knight.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.