Marking earth wires with yellow aviation balls reduces avian collision mortality in South Carolina
Published source details
Savereno A.J., Savereno L.A., Boettcher R. & Haig S.M. (1996) Avian Behavior and Mortality at Power Lines in Coastal South Carolina. Wildlife Society Bulletin, 24, 636-648
Published source details Savereno A.J., Savereno L.A., Boettcher R. & Haig S.M. (1996) Avian Behavior and Mortality at Power Lines in Coastal South Carolina. Wildlife Society Bulletin, 24, 636-648
This study is summarised as evidence for the following.
Mark power lines to reduce incidental bird mortalityAction Link
Mark power lines to reduce incidental bird mortality
A paired sites study in 1991-4 in coastal wetlands in South Carolina, USA (Savereno et al. 1996), found a 53% reduction in collision mortalities at a 3.9 km span of 115 kV transmission lines where the static wires were marked, compared to a 1.2 km unmarked span. A higher proportion of birds approaching marked wires at the most dangerous height (between transmission wires and earth wire) reacted to them, compared to unmarked wires (98% of 9,819 flocks vs. 89% of 4,209 flocks respectively) and fewer crossed the wires at this height (4% vs. 24%). However, overall, a higher percentage of birds reacted to lines at unmarked spans (40% of 17,391 flocks vs. 34% of 64,512 flocks). The experimental span was marked with yellow aviation balls (30 cm in diameter with a vertical black stripe) at 61 m intervals, staggered to give the appearance of a 30.5 m spacing.