Mitigation techniques to reduce avian electrocution rates

Abstract

From August 2013, we undertook a 1-year trial of mitigation techniques at an electricity power line in the Mongolian steppe with a high avian electrocution rate. We examined 2 mitigation methods at phase-1 conductors on the top of power poles (i.e., reconfiguration of the insulator mount and insulation covers on the conductor wire) and 3 mitigation methods at phase-2 and 3 conductors on pole cross-arms (i.e., perch deflector brushes, rotating-mirror perch deterrents, and insulation covers on the conductor wires). The perch management techniques selected for the trial are currently widely adopted by power line managers in Mongolia. In comparison with the control, with no mitigation, electrocution rates were reduced both by the reconfiguration of insulator mounts and insulation of conductor wires at phase-1, though the reduction was greater for the former-73% mean reduction for reconfigured mounts and 59% for insulation covers. Electrocution rates were reduced by the placement of rotating-mirrors and insulation of conductor wires at phases 2 and 3, with the reduction being greater for the former-91% mean reduction for mirrors and 66% for insulation covers. Deployment of metal perch deflector brushes at phases 2 and 3 had no effect on electrocution rates and should not be used as mitigation. Most electrocutions occurred at phase 1 on the top of the pole, indicating that mitigation should be prioritized at this phase. In terms of cost and efficacy, reconfigured mounts represented the best option as a permanent fix at phase 1. At phases on cross-arms, the relative merits of mirrors and insulation covers need to be assessed over a longer period, and these temporary mitigation measures should be compared with alternative permanent fixes.

Do supplemental perches influence electrocution risk for diurnal raptors?

“…Our work suggests, in line with previous studies (Janss and Ferrer 1999;Dixon et al 2019), that supplemental perches reduce electrocution risk. However, the results are not homogeneous among species.…”

Can an Avian Electrocution Risk Model From California Guide Retrofitting Throughout the Western United States?

“…Of these, 21 reported more electrocutions on more complex structures than on tangent structures. Many reported electrocutions of various species, often including eagle species, such as bald eagles Haliaeetus leucocephalus (Harness and Wilson 2001), Bonelli's eagles Aquila fasciata (Tintó et al 2010;Guil et al 2011), chaco eagles Buteogallus coronatus (Sarasola et al 2020), eastern imperial eagles Aquila heliacal (Gális et al 2019), Spanish imperial eagles Aquila adalberti (Janss and Ferrer 2001;Guil et al 2011), steppe eagles Aquila nipalensis (Matsyna et al 2011;Dixon et al 2019), tawny eagles Aquila rapax (Harness et al 2013), and white-tailed eagles Haliaeetus albicilla (Demeter et al 2018). Across species, electrocutions were associated with more complex structures.…”

“…We did not find a single study indicating tangent structures were equally dangerous or more dangerous to golden eagles specifically, or to birds generally, than non-tangent structures. Patterns illustrating the risk-relationship between equipment and grounding were particularly apparent in India, Hungary, and Mongolia (Harness et al 2013;Demeter et al 2018;Dixon et al 2019) where nearly all configurations, including tangents, involved grounded structures. Tangent structures in those locations were associated with increased numbers of electrocutions, but even then, intersection and equipment structures had greater numbers.…”

Importance of Power Pole Selection When Retrofitting for Eagle Compensatory Mitigation

“…Avian electrocution risk varies among poles (Harness and Wilson 2001;Cartron et al 2005;Ferrer 2012;Dixon et al 2019). Complex configurations have more wires, pole-mounted equipment, and grounded surfaces (Dwyer and Mojica 2021).…”