Contending that “the current situation is particularly worrying”, authors of a troubling new paper assert that the bat habitat loss fomented by the presence of wind turbines is so pervasive that bat activity continues to decline precipitously from a range of “at least 1000 meters from a wind turbine”.
Image Source: Millon et al., 2018
Wind turbines negatively affect the well-being of nearby human populations
It is well established that situating wind turbines near human populations has a “significant negative and sizable effect on life satisfaction” and well-being (Krekel and Zerrahn, 2017). This harm can affect households as far as 4,000 meters away from a wind turbine.
“We show that the construction of wind turbines close to households exerts significant negative external effects on residential well-being … In fact, beyond unpleasant noise emissions (Bakker et al., 2012; McCunney et al., 2014) and impacts on wildlife (Pearce-Higgins et al., 2012; Schuster et al., 2015), most importantly, wind turbines have been found to have negative impacts on landscape aesthetics (Devine-Wright, 2005; Jobert et al., 2007; Wolsink, 2007). … We show that the construction of a wind turbine within a radius of 4,000 metres has a significant negative and sizable effect on life satisfaction. For larger radii, no negative externalities can be detected.” (Krekel and Zerrahn, 2017)
The critical role of bats in natural ecosystems
Bat species can be found dwelling in a wide variety of terrestrial habitats, including deserts and along sea coasts. Each bat species may play a fundamental role in the local ecosystem.
For example, Kuntz et al., (2011) indicate that 528 different plant species rely on bat pollination and seed dispersal for sustainability.
Boyles et al., (2011) estimated that by controlling pest populations (insects), the agricultural benefits of bats may reach $22.9 billion (U.S.D.) annually in the continental U.S. alone.
A 20-fold loss of bat habitat at sites where wind turbines are located
Last March a scientific paper was published in the journal Ecological Engineering documenting the profound loss of bat habitat use at locations where wind turbines have been installed.
Not only is mortality due to collision endangering rare bat species, but the mere existence of wind turbines at previously undisturbed sites may have the effect of reducing bat activity (i.e., flying passes) twenty-fold, effectively despoiling bat habitats. This phenomenon is reportedly occurring on a “worldwide” scale.
“Wind turbines impact bat activity, leading to high losses of habitat use … The result of the study demonstrates a large effect on bat habitat use at wind turbines sites compared to control sites. Bat activity was 20 times higher at control sites compared to wind turbine sites, which suggests that habitat loss is an important impact to consider in wind farm planning. … Here, we provide evidence showing that two genera of insectivorous bat species are also threatened by wind farms. … To our knowledge, this is one of the first studies quantifying the indirect negative impact of wind turbines on bat activity in the tropics. … The lower attractiveness of the foraging habitat under wind turbines, both in a tropical and in a temperate climate, indicates that the indirect impact of wind turbine is a worldwide phenomenon.” (Millon et al., 2018)
Bat populations at risk for extinction due to wind turbine installation
In addition to White Nose Syndrome, deaths connected to collisions with wind turbines are now the leading cause of multiple mortality events in bats (O’Shea et al., 2016).
Roughly 25% of North American bats are now classified at risk for extinction (Hammerson et al, 2017) in large part due to the explosion of wind turbines across the landscape.
If the expansion of wind turbines continues at its current pace, the hoary bat population is projected to be reduced by 90% (Frick et al., 2017) within the next 50 years.
As Hein and Schirmacher (2016) conclude, the “current and presumed future level of fatality [for bat populations] is considered to be unsustainable.”
New paper quantifies the “worrying” range of wind turbine-induced bat habitat loss
In a new paper published in the journal Biological Conservation, French ecologists provide quantification for the range of habitat loss caused by the installation of wind turbines at locations where high bat activity exists.
The dispiriting results indicate that the radius for the loss of habitat due to wind turbine presence may extend at least 1,000 meters from each individual wind turbine.
Even more troubling, 89% of NW France’s 909 wind turbines assessed for the study are currently located less than 200 meters from natural bat habitats, implicating France’s complicity in habitat despoliation.
As Barré et al., 2018 conclude, “there is an urgent need to assess the potential decrease in bat activity close to wind turbines.”
Estimating habitat loss due to wind turbine avoidance
by bats: Implications for European siting guidance
• “Wind energy is rapidly growing as a renewable source of energy but is not neutral for wildlife, especially bats. Whereas most studies have focused on bat mortality through collision, very few have quantified the loss of habitat use resulting from the potential negative impact of wind turbines.”
• “We quantified the impact of wind turbines at different distances on the activity of 11 bat taxa and 2 guilds. … We found a significant negative effect of proximity to turbines on activity for 3 species (Barbastella barbastellus, Nyctalus leisleiri, Pipistrellus pipistrellus), 2 species-groups (Myotis spp., Plecotus spp.) and 2 guilds (fast-flying and gleaner).”
• “The current situation is particularly worrying, with 89% of 909 turbines established in a region that does not comply with recommendations, which themselves are far from sufficient to limit the loss of habitat use.”
• “[T]here is an urgent need to assess the potential decrease in bat activity close to wind turbines in order to quantify the changes of habitat use and the distance of impact. This possible underestimated impact of wind turbines could constitute an important concern, affecting population dynamics with a loss of habitat availability (Rodrigues et al., 2015).”
• “[F]or most species, the negative effect of wind turbines on activity extends at least 1000 m from a wind turbine. The lost activity was therefore likely underestimated and occurred at > 1000 m. … Bat activity within 1000 m of wind turbines by gleaners and fast-flying bats is reduced by 53.8% and 19.6%, respectively.”
• “Thus, the percentage of lost activity was high, even at long-distances: for instance, at 500 m from the nearest turbine, we detected activity losses of 57% and 77% for P. pipistrellus and the gleaner species guild, respectively.”
• “Among the 909 wind turbines in northwest France, which contained the studied farms, 89% were established at < 200 m from any type of wooded edges (forest or hedgerows).”