Efficacy and Underpinnings of the Effigy in Wildlife Management

Displaying representations or actual individuals of the same or similar species can have a congregating or deterring effect on animals. An effigy, an animal or animal representation in a moribund state, is a tool aimed at deterring target animals in wildlife management settings. Despite being used as a deterrent for decades, neither a synthesis of effigies nor an exploration of the behavioral drivers tied to effigy effectiveness has occurred. We reviewed the effigy literature in terms of both efficacy as a deterrent and behavioral driver(s). We examined research on effigies encompassing 13 social avian species. Nine of seventeen (53%) investigations included experimentation and statistical validation, and of those, six of nine (66%) found effigies to be effective at deterring the focal species, though the temporal scale and spatial extents of the investigations were highly variable. We argue that central to an effigy's effectiveness is the elicitation of fear in the target animal(s) and propose and discuss several potential drivers of fear derived from an effigy, namely antipredator behavior, neophobia, and disgust. Only a single study discussed behavioral drivers of effigy response. We conclude that effigies show promise as a wildlife deterrent for social avian species and have potential for uninvestigated species, and greater efforts should be made to incorporate robust study designs capable of strong inference and elucidation of behavioral drivers of an animal's response to an effigy.