Michael J. Lavelle

Fences and Deer-Damage Management: A Review of Designs and Efficacy

Abstract White-tailed deer (Odocoileus virginianus) may cause more damage than any other species of wildlife. These damages include crop loss, automobile and aviation collisions, disease transmission, environmental degradation, and destruction of ornamental plantings. One practical method of controlling deer damage is the use of exclusionary fences. The relatively high cost of labor and materials required to build effective fences has limited most applications to the protection of orchards, vegetable farms, other high-value resources, and mitigation of human health and safety risks. Improvements in fence technology resulting in less expensive, yet effective fences have expanded the use of fences to manage damage caused by deer. Fences typically installed to manage white-tailed deer damage include wire or plastic mesh, electrified high-tensile steel wire, and electrified polytape or polyrope fence. We reviewed the scientific literature on fencing to determine which fence designs would be the most effective for excluding deer in a variety of situations.

Livestock Protection Dogs for Deterring Deer From Cattle and Feed

Abstract Disease transmission between wildlife and livestock is a worldwide issue. Society needs better methods to prevent interspecies transmission to reduce disease risks. Producers have successfully used livestock protection dogs (LPDs) for thousands of years to reduce predation. We theorized that LPDs raised and bonded with cattle could be used to also reduce risk of bovine tuberculosis (Myobacterium bovis; TB) transmission between white-tailed deer (Odocoileus virginianus) and cattle by minimizing contact between the 2 species and use of cattle feed by deer. We evaluated 4 LPDs over 5 months, utilizing 2 data collection methods (direct observation and motion-activated video) on deer farms that supported higher densities than wild populations. Dogs were highly effective in preventing deer from using concentrated cattle feed (hay bales), likely the greatest risk factor of TB transmission on farms. Dogs also prevented deer from approaching cattle in core areas of pastures (near hay bales) and were very effective throughout pastures. Our research supports the theory that LPDs, specifically trained to remain with cattle, may be a practical tool to minimize potential for livestock to contract TB from infected deer in small-scale cattle operations. Where disease is present in deer, it may be possible to reduce the potential for disease transmission by employing LPDs.

Management of damage by elk (Cervus elaphus) in North America: a review

Abundant populations of elk (Cervus elaphus) are cherished game in many regions of the world and also cause considerablehuman-wildlifeconflictsthroughdepredationonagricultureandspecialitycrops,lackofregenerationtonative ecosystems,collisionswithvehiclesandtransmissionofdiseasebetweenfree-rangingandfarmedhoofstock.Managementof elk varies, depending on current and historical agency objectives, configuration of the landscapes elk occupy, public perception, population density and behaviour of elk. Selection of the method to manage elk often requires knowledge of timing of impacts, duration relief from elk damage is desired, cost-effectiveness of management activities, tolerance of impacts, public perception of management strategies and motivation or habituation of elk to determine the likelihood of success for a proposed management action. We reviewed methods that are available to control abundant populations of elkthatincludelethal(e.g.hunting,sharpshooting)andnon-lethal(e.g.fertilitycontrol,frightening)options.Wepromotean integrated approach that incorporates the timely use of a variety of cost-effective methods to reduce impacts to tolerable levels.Lethaloptionsthatincluderegulatedhunting,sharpshootingandaerialgunningvarybylikelihoodofsuccess,duration neededforpopulationreduction,costtoimplementreductionandpublicperceptions.Severalnon-lethaloptionsareavailable to affect population dynamics directly (e.g. fertility control, translocation), protect resources from damage (e.g. fences, repellents) or influence space use of elk on a regular basis (e.g. harassment, frightening, herding dogs, humans). Public perceptionshouldbeconsideredbyagenciesthatarelookingforfeasiblemethodstocontrolpopulationsofelk.Disturbance to residents or visitors of public property may influence methods of management employed. Future research should explore thedurationofharassmentneededtoavertelkfromsensitiveareasandcoststoimplementsuchprograms.Severalmethodsin ourreviewwereimplementedondeerandadditionalresearchonelkandothercervidsinconflictwithhumaninterestswould provide a much needed component to our understanding of management methods available for ungulate species.

Efficacy of an animal-activated frightening device on urban elk and mule deer

Abstract Cervids readily adapt to suitable human-altered landscapes and can cause several types of damage, including economic loss associated with landscape and agricultural plantings, human health and safety concerns, and adverse impacts on natural habitats. The need for effective, practical, and nonlethal tools to manage damage caused by elk (Cervus elaphus), mule deer (Odocoileus hemionus), and white-tailed deer (Odocoileus virginianus) has been heightened by the growing prevalence of locally overabundant populations and public demand for nonlethal wildlife management methods. Various frightening devices are available commercially, but most have not been subjectively evaluated. We used consumption measurements to evaluate the efficacy of a specific motion-activated light- and sound-emitting frightening device for urban mule deer and elk. The devices proved ineffective; deer and elk ignored them. As the demand for frightening devices to reduce deer and elk damage increases, it is important that research be conducted to evaluate the efficacy of new devices so that users know what level of efficacy to expect.

Fence-Line Contact Between Wild and Farmed White-Tailed Deer in Michigan: Potential for Disease Transmission

Abstract Interactions between wild and farmed white-tailed deer (Odocoileus virginianus) along perimeter fences may play a role in the transmission of diseases like bovine tuberculosis and chronic wasting disease. However, no study has evaluated direct contact between wild and farmed deer through fences. We used animal-activated cameras to estimate rates of interaction between wild and farmed deer at 6 high-fenced commercial white-tailed deer farms in Michigan, USA, during October 2003 to January 2005. We recorded only 2 direct, naso-oral contacts between wild and farmed deer during >77,000 hours of camera monitoring. We documented little direct contact between wild and captive deer through fences and, therefore, believe there is limited potential for direct transmission of diseases. However, we suspect our results are conservative and do not rule out the risks of direct or indirect disease transmission into or out of deer farms. Our findings will be of use to federal and state agencies responsible for regulating deer farms as well as managers of such facilities.

Elk Use of Wallows and Potential Chronic Wasting Disease Transmission

Deposition of prions into the environment by infected animals may contribute to transmission and spread of chronic wasting disease (CWD) among free-ranging cervids, and identification of such environmental sources may provide an avenue for managing CWD. We evaluated the role that wallow use by elk (Cervus elaphus) may play in CWD transmission by monitoring wallows with animal-activated cameras throughout their period of use. We monitored 39 wallows from 5 August 2005 to 14 October 2005. Elk visited 20 sites; we recorded 22 events when only male elk wallowed and 374 additional events when male and female elk had naso-oral contact with wallow contents. Because wallows are foci of male elk activity, behaviors at wallows could potentially contribute to the maintenance and transmission of CWD. Our findings, however, suggest that because wallows are only used an average of one or two times a season they may not be important in CWD transmission. The data also suggest that mineral licks could be more important in CWD transmission because they were used more frequently and by three species that contract CWD.

Evaluation of Fences for Containing Feral Swine under Simulated Depopulation Conditions

ABSTRACT Populations of feral swine (Sus scrofa) are estimated to include >2 million animals in the state of Texas, USA, alone. Feral swine damage to property, crops, and livestock exceeds

Assessment of Abilities of White-Tailed Deer to Jump Fences

50 million annually. These figures do not include the increased risks and costs associated with the potential for feral swine to spread disease to domestic livestock. Thus, effective bio-security measures will be needed to quickly isolate affected feral swine populations during disease outbreaks. We evaluated enclosures built of 0.86-m-tall traditional hog panels for containing feral swine during 35 trials, each involving 6 recently caught animals exposed to increasing levels of motivation. During trials, fences were 97% successful when enclosures were entered by humans for maintenance purposes; 83% effective when pursued by walking humans discharging paintball projectors; and in limited testing, 100% successful when pursued and removed by gunners in a helicopter. In addition to being effective in containing feral swine, enclosures constructed of hog panels required simple hand tools, took <5 min/m to erect, and were inexpensive (

Fence‐Line Contact Between Wild and Farmed Cervids in Colorado: Potential for Disease Transmission

5.73/m excluding labor) relative to other fencing options. As such, hog-panel fences are suitable for use by state and federal agencies for rapid deployment in disease response situations, but also exhibit utility for general control of other types of damage associated with feral swine.

A Simulation Model for Determining Cost-Effectiveness of Fences for Reducing Deer Damage

Abstract There is a need for insight into fence heights required for impeding white-tailed deer (Odocoileus virginianus). We evaluated the ability of wild-caught deer to jump progressively taller fences and documented deterrence rates of 0% for fences ≤1.5 m followed by increasing deterrence rates of 14% at 1.8 m, 85% at 2.1 m, and 100% at 2.4 m. We documented 100% deterrence rates during 5 additional experiments with different deer and the test fence at 2.4 m, a common height of fences at captive deer facilities. Our results will be valuable to those managing spread of wildlife diseases, deer–vehicle collisions, and agricultural damage.