By Nathan Lance
Although wolves may not have drastic economic repercussions on the livestock industry as a whole, they can substantially affect individual ranchers when depredations become chronic. This creates a difficult environment in which to balance wolf conservation with other human interests. Modifying predator and human behavior, as well as a thorough understanding of biological and sociological factors associated with these conflicts, are essential for successful predator conservation and management.
Lethal removal of problem individuals is still used as a traditional management strategy; however, new, non-lethal management tools that decrease risk of predation provide additional flexibility to both livestock producers and conservationists.
Tools such as fladry can be very effective by exploiting natural predator behaviors like fear and avoidance. It uses flagging interspersed along a line and strung across fences surrounding livestock pastures. The flagging triggers an innate fear and avoidance in wolves, because it is a novel stimulus. However, it has the potential to be rendered ineffective through the process of habituation.
Alternatively, the effectiveness of a stimulus such as fladry can be magnified when animals learn to avoid it altogether by associating it with a negative experience in a process called "aversive conditioning." For example, in the case of "Turbo-fladry," a predator’s fear response is reinforced when a second stimulus, such as electric shock, acts as a reinforcing deterrent. This technique prolongs the repellent effect and is not susceptible to habituation, because of the supplemental aversive conditioning element.
My research objective was to determine the effectiveness and usefulness of electrified fladry for preventing wolves from accessing a protected food resource or a pasture. We tested this technique with captive wolves in Minnesota, as well as on nine ranches in Montana that had historic wolf conflicts.
My research indicated that electrified fladry was successful at changing captive wolf behavior, and has the potential to reduce wolf depredations on ranches, while providing sociological benefits to management. However, animal learning, motivation and personality all influence its effectiveness. Logistic and economic considerations may also limit its use to smaller applications, since about $3,685 of investment is required for a relatively small 40 acre pasture.
It is possible that limiting the evaluation of a tool to its economic cost-benefit ratio may erroneously discount the biological and sociological importance of electrified fladry. Managers will need to weigh the costs and maintenance against the risk of damage and management objectives.
It is argued that non-lethal management only delays the inevitable lethal removal of a depredating wolf, just as lethal removal subsequently delays the inevitable colonization and damage by another wolf filling the recently vacated niche. Thus, both types of management have been criticized, since they require actions that seem doomed to fail.
It is important to acknowledge, however, that lethal control is not a proxy for non-lethal techniques, nor are non-lethal tools a replacement for lethal control. Rather, a perpetual management employing a combination of tools that promote livestock protection, foster human tolerance, and maintain a viable carnivore population will be unrivaled. Ultimately, solutions to predator-livestock conflicts need to evolve from an understanding and balance of the biological, economical and sociological contexts in which these problems exist.
Nathan Lance is a wolf management specialist with Montana Fish, Wildlife & Parks. He received his B.S. in wildlife biology from the University of Montana and an M.S. in wildlife biology from Utah State University. For the last eight years, his work has focused on wolf and bear ecology and minimizing conflict with carnivores and humans.