The rising concerns over the long-term environmental effects of fossil fuel usage have caused people to consider renewable energy as an important alternative solution for the electrical power industry. Hence, the increasing number of wind farms and solar panel farms over the last few decades. Supposedly renewable energy brings no harm to the environment, but the hidden truth is, the growing number of these facilities in general, might have impacts on wildlife. What can we do to make these green energies, greener? Is there any action that could be taken to reduce all these potential threats?
Bat killed by a wind turbine on Buffalo Mountain. Chris M Morris
For now, let’s talk about the risk of wind farm facilities to wildlife, especially for birds and bats.
Concern about wildlife mortality at wind farms began to surface in the late 1980s and early 1990s, where thousands of birds died every year, including endangered one (Asmus, 2005; Smallwood and Thelander, 2008) either in the USA (Erickson et al., 2001) or even in Europe (Lowther, 1998; Everaert and Stienen, 2007). Baerwald et al (2008) and Garvin et al (2011) have investigated the impacts of wind farm development on bird populations and shown that the effects can be fickle. It might depend on differences of aspects including the turbine type, the land topography, the surrounding habitat, and the species present (Barrios and Rodriguez, 2004). According to Carrete et al (2012), grouse, raptors, terns, and gulls tend to collide more often with wind farm infrastructure. White-tailed sea eagles in Norway, golden eagles in California, and Tasmanian wedge-tailed eagles in Australia are among of endangered species that are affected from wind farm (Sanchez-Zapata et al., 2016).
Another group that is afflicted by a wind farm is bats, especially tree-roosting bats (Arnett et al., 2008; Grodsky et al., 2011; Voigt et al., 2012). The first report on bat fatality was during the 1990s and occurred in Europe and North America (Kunz et al., 2007). Since then, research and monitoring have been carried out around wind farms to see the implications on bats (Rydell et al., 2010; Parsons and Battley, 2013; Arnett and Baerwald, 2013; Cryan et al., 2014). Although the information about the impacts of wind farms on bat population is still lacking, based on a study by Grodsky et al (2011), out of 39 bats carcasses found around wind farms, 74% had bone fractures, primarily in wing bones. Thus, the cumulative impacts of this new hazard could result in long-term population declines or even extinctions in certain areas (Kunz et al., 2007). This problem arises when bats confuse the turbines with tree silhouettes (Cryan et al., 2014) and are attracted to wind turbines because of curiosity, potential foraging area, or social interactions (Cryan and Barclay, 2009).
Potential mitigation to minimize the risk?
The high mortality rate caused by wind facilities poses a serious threat to these flying animals unless solutions are developed and implemented. Perhaps the most effective ways needed for conservation is to predict and evaluate how a wind turbine impacts on local and migratory animals based on previous studies. Thus, the best measure to minimize the collision risk on migratory birds and bats is to identify their roosting area and migration routes and avoid positioning the wind farm in this location. Predicting the collision risk by modeling the seabird flight heights can be one of the solutions to reduce the negative effects of wind farm on birds (Ross-Smith et al., 2016). Another effective management strategy to reduce bat fatalities is to increase the turbine’s cut-in speed (the speed which wind turbine become operational) in late summer and early autumn at night. Preventing rotor blades from turning at low wind speeds, resulting in fewer bat fatalities in previous studies. Other than that, it is suggested to remove turbine lighting to reduce insect’s attraction, hence lowering the bat’s foraging activity near the wind farm.
We will talk about the impacts of solar power farms on wildlife, and the mitigation, on the next post!
By: Amira Rahman
*Note: I would like to thank Reka, Syahid and Beth for their suggestions and comments for this post.
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References:
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Arnett, E.B., & Baerwald, E.F. (2013) Impacts of wind energy development on bats: Implications for conservation. Bat Evolution, Ecology, and Conservation, eds Adams RA, Pedersen SC (Springer, New York), pp 435–456.
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