According to a study done in the University of Colorado, more than 600,000 bats were killed by wind energy turbines in 2012. That is more than 10 times the amount of American soldiers killed during the whole of the Vietnam War. This is a serious blow to this amazing population of mammals that are integral to the world’s ecosystem. You see Bats are pretty amazing, they not only pollinate crops, flowers and cacti, they also help with the control of flying insects, like mosquitos with one bat eating more than 6,000 insects a night.
“The development and expansion of wind energy facilities is a key threat to bat populations in North America,” said study author Mark Hayes, PhD, research associate in integrated biology at CU Denver. “Dead bats are being found underneath wind turbines across North America. The estimate of bat fatalities is probably conservative.”
The study was taken by analysing the data from the number of dead bats found surrounding wind turbine sites and it was published in the journal, BioScience.
According to Hayes, areas near the Appalachian Mountains like Buffalo in Tennessee and Mountaineer in West Virginia had the highest fatality rates for bat. Information was scarce on bat losses at wind turbines in the Rocky Mountain West or the Sierra Nevadas. Earlier estimates of bat fatalities were incredibly varied and ranged from 33,000 to 880,000, and Hayes believes his estimate of 600,000 is probably conservative.
His theory has two factors. First, when a range of bat fatality estimates were reported at a wind facility, Hayes would choose the minimum estimate. Secondly, the number of deaths was estimated during migratory periods and not the entire year, this means the study has probably omitted many other deaths. Hayes, who has studied bats for 15 years said that “The number could be as high as 900,000 dead,”
The bat species suffering the most fatalities are the hoary bat, eastern bat and the silver-haired bat.
Hayes has suggested methods that could stop anymore bat-turbine related deaths, such as having the turbines activated to spin at higher wind speeds when bats don’t tend to fly. Making similar amounts of energy, but with less chance of doing damage to the bat population.
“A lot of bats are killed because the turbines move at low wind speeds, which is when most bats fly around. In a recent study in Pennsylvania, researchers adjusted the operating speeds from 10 mph to 18 or 20 mph and decreased fatalities by 40 to 90 percent.”
Hayes believes that with expansion of wind energy in the future, even more bats are likely to fall to their deaths. Although Hayes is not adverse to the benefits of wind power, “I am not against wind energy. It’s clean, it reduces pollution and it creates jobs. But there are negative impacts,” he said. “Still, I think this is a problem we can solve.”
For information on British bats look at websites that offer information, such as these bat surveys from Arbtech.co.uk