Scientists believe that bats are suffering unusually high mortality rates because of wind turbine-related deaths. In a study recently published in BioScience, scientists surveyed the number of dead bats found at 21 wind energy facilities and based on that number ran analysis and extrapolated to estimate how many bats were dying as a result of wind turbine impact in 2012. They estimate the number at around 600,000 bats.
Bats can be killed by a wind turbine in one of two ways. First, they can be killed from impact with the wind turbine blade. A more stealthy killer, however, is the change in air pressure caused by the blades. The number is actually a conservative estimate; up to 50 percent more bats could in fact have been killed by the turbines, a press release obtained by EurekAlert reports.
Bats are an important part of ecosystems because they conduct minor pollination operations and act as insect control, consuming insects during the nighttime hours. The consequences of the unnatural bat deaths are hard to estimate, however, because there is no good estimate available of how many bats are in the U.S., so it is difficult to know whether the number of bats killed is significant in terms of population size. Bats are facing other population threats, however, so the situation is deserving of more research.
The researchers believe that more bats are being killed in the Appalachian Mountains than in other locations around the country, raising questions as to why that area of the country is more affected by the issue. Bats are highly vulnerable to changes in the environment, and bat populations worldwide have been on the decline for several decades, the International Business Times explains. Bats have a very low reproductive rate, and young bats have a high mortality rate. Female bats only give birth once per year, so repopulating the species would take considerable time and effort.
Another recent threat to bats is a white fungus that has killed six million American bats since it emerged seven years ago. Named white-nose syndrome, it is now present in 22 states, complicating efforts to examine bat populations. Wind farms are just the latest threat to the bat species, and have been known to kill birds as well. Wind farms consist of many wind turbines (perhaps around 50) and are becoming more prevalent in the United States as individuals, companies and the government seek to reduce the country’s dependence on oil.