What is the effectiveness of using conspecific or heterospecific acoustic playbacks for the attraction of animals for wildlife management? A systematic review protocol

BACKGROUND: Many animals are attracted to the sounds of their conspecifics and some are attracted to the sounds of other species. Therefore, wildlife managers have begun to capitalize on this attraction to lure animals to specific places by broadcasting vocalizations—a method referred to as acoustic playback. Playbacks have been conducted to attract animals for capture, encourage birds to use specific nest boxes, attract animals to safe locations where they can breed, or to lure animals to habitats away from human disturbances. However, there has been no evaluation of the general effectiveness of this intervention on the attraction of animals for wildlife management. We describe a protocol to systematically review the literature of the effectiveness of using playbacks so that conservation practitioners can make informed wildlife management decisions. METHODS: The review will examine primary field studies that use acoustic playbacks to attract animals for wildlife management. Playbacks could be of conspecifics, heterospecifics, or both. We will search various bibliographic databases, online search engines, and specialist websites for relevant studies. We will screen studies first on title and abstract, then on full text. We will only include studies that measure quantitative results. Relevant outcomes will include the attraction of animals to playbacks and encompass various management goals: to capture the animal, to persuade the animal to use a new breeding location, and/or to persuade the animal to settle in a location during the study duration. Studies must be based on comparison between conditions before and after intervention, on comparison between treatment and control plots, or both. Inter-reviewer consistency in article inclusion will be performed with 10% of the titles and abstracts and 10% of the full texts. We will critically appraise the literature based on study type and design, sample sizes, study duration, and other aspects of methodology. We will extract data and meta-data including various potential effect modifiers (e.g., taxon). Finally, we will evaluate the effectiveness of playbacks through a narrative synthesis of the evidence, and quantitative synthesis (i.e., meta-analysis) if sufficient data (more than two studies) of similar outcomes are found.