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| Fig. 1: Picture of a completely white wind turbine. (Source: Wikimedia Commons) |
Wind Turbines are one of the largest providers of renewable energy in the United States. However, in 2013, it was estimated that between 140,000 and 328,000 birds were killed due to colliding with wind turbines. [1] The goal of this report is to put the number of birds killed by wind turbines in context.
Birds often perceive the path traveled by wind turbine blades as an open area which causes them to fly into the blades. However, wind turbines have a comparatively low number of avian fatalities when weighed against other structures. In 2013, the US Fish and Wildlife Service estimated that around 4 to 5 million birds were killed each year by communications towers. At the time, there were only about 77,000 towers in the US. [2] In 1991, it was estimated that about 98 million birds died from plate glass collisions. [3] Birds do not perceive the reflections of glass as a reflection but reality, so they do not hesitate to fly into them, often resulting in their deaths
A study done in a Norwegian wind-power plant found that when an ordinary wind turbine, such as the one in fig. 1, had a single blade painted black, bird fatalities were reduced by about 70%. [4] This could significantly reduce the number of bird-wind turbine fatalities if widely implemented.
Wind turbines cause the deaths of thousands of birds every year. However, this is a small number compared to other causes of avian death and does not significantly impact bird populations. For what avian fatalities wind turbines do cause, there are measures that can be taken to significantly reduce them.
© Garin Gross. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] S. R. Loss, R. Will, and P. P. Marra, "Estimates of Bird Collision Mortality at Wind Facilities in the Contiguous United States," Biol. Conserv. 168, 201 (2013).
[2] G. Shire, K. Brown and G. Winegrad, "Communication Towers: A Deadly Hazard to Birds," American Bird Conservatory, June 2000.
[3] D. Klem, Jr., "Glass and Bird Kills: An Overview and Suggested Planning and Design Methods of Preventing a Fatal Hazard," in Wildlife Conservation in Metropolitan Environments,ed. by L. W. Adams and D. L. Leedy (Natl. Inst. for Urban Wildlife, 1991), p. 99.
[4] R. May et al., "Paint It Black: Efficacy of Increassed Wind Turbine Rotor Blade Visibility to Reduce Avian Fatalities," Ecol. Evol. 10, 8927 (2020).
