Date of this Version
Published in G.M. Linz, M.L. Avery, and R.A. Dolbeer, editors. Ecology and management of blackbirds (Icteridae) in North America. CRC Press, Boca Raton, FL. Pgs. 159-174.
By their nature, avian frightening devices are intended to provide temporary (days, weeks) relief from a specific depredation or conflict situation. Ideally, the method applied will produce an immediate fright response, causing depredating birds to leave and to stay away as long as the method is in place. Longer-term (months, years) resource protection would involve methods such as crop varietal improvement, blackbird population management, or habitat manipulation. Frightening devices primarily affect the avian auditory and visual senses. With few exceptions (e.g., avian distress or alarm calls), frightening devices are not species-specific.Very few frightening devices have been subjected to adequate scientific evaluation, so their efficacy under field conditions is often unknown. When field tests have been conducted, flaws in experimental design and analysis have rendered most trials inconclusive as to their effectiveness (Bomford and O'Brien 1990). Anderson et al. (2013) surveyed fruit crop producers in five states and reported that >50% of respondents considered "auditory scare devices" to be "slightly effective" or "not effective" in reducing bird damage. The specific types of auditory deterrents were not indicated. Relatively few published reports of frightening devices include testing against blackbirds. Therefore, the usefulness of many aural and visual devices for managing blackbirds can only be judged by extrapolating from studies that have focused on species other than icterids, such as corvids and gulls, in settings such as landfills and orchards, which are not usually associated with blackbirds.