The primary aim of a virtual fence is to manipulate the animals “Landscape of Fear” to create areas which are perceived to be scarier than others. This is achieved by simulating the presence of natural predators, territorial competitors or providing painful, unpleasant or scary stimuli (e.g. distress and/or alarm calls, loud bangs).
The integrity of the virtual fence requires that the boundary is spatially predictable while the production of the stimuli is temporally unpredictable. This uncertainty creates stress, which enhances the fear, and hence the efficacy of the virtual fence.
The HWS Virtual Fence produces a variety of stimuli (alarm calls, predator calls, sounds of dying animals, predators squabbling and pyrotechnics) which create stimulus unpredictability, thus minimizing the chances of habituation. The virtual fence manipulates the animal’s “Landscape of Fear” to create areas that are perceived to be scary, and hence are avoided.