Species-Specific Effects of a Sound Prototype to Reduce Bird Use of Powerline Poles

Abstract

Powerlines pose a significant threat to many bird species, impacting their conservation. Current research focuses on developing methods to mitigate bird mortality due to electrocution and collisions with powerlines. In this study, we designed a sound prototype to be installed on infrastructure poles, including powerlines, aiming to reduce their use by birds. We conducted bird surveys over 47 days, from February to May 2020, in five light poles: the central pole where the device was installed (0 m), two poles at 25 m, and two poles at 50 m from the central pole. The first 10 days served as a control period with the deterrent device switched off, followed by 37 days with the device switched on. In total, we recorded 1945 bird observations, of which 1569 occurred with the device on. The device was triggered by bird movements, resulting in 588 reactions to sound. When activated, 10.6% of large- and medium-sized birds were flushed from the surveyed poles: 2.6% were already perched and flushed due to the sound, 3.9% were prevented from perching, and 4.1% were flushed after perching, thereby reducing the risk of electrocution. Among the birds perching or approaching the pole where the device was installed, 25% were deterred by the sound. The black kite, Milvus migrans, was the most reactive species to the device (54.3% flushed at 0 m, and 8.8% flushed at 25 and 50 m), while the white stork, Ciconia ciconia, showed the least sensitivity to the disturbances (14.4% flushed at 0 m, and 2.7% flushed at 25 and 50 m). The corvids exhibited a response rate between the other two species (33.3% flushed at 0 m, and 6.8% flushed at 25 and 50 m). We identified significant limitations to this prototype and proposed recommendations to improve its efficiency.