Wind Turbines and…bats

How this two relate, you might ask yourself-it seems that the Power-generating wind turbines are life-threatening hazard for birds but mostly bats. Ninety percent of the dead bats examined, presented signs of internal hemorrhaging and trauma from the sudden drop in air pressure (also known as ” barotrauma”) formed by the turbine blades. Half of the bats showed clear evidence of direct contact with the blades.

“Because bats can detect objects with echolocation, they seldom collide with man-made structures,” ( Erin Baerwald of the University of Calgary in Canada). “An atmospheric-pressure drop at wind-turbine blades is an undetectable—and potentially unforeseeable—hazard for bats, thus partially explaining the large number of bat fatalities at these specific structures.

“Given that bats are more susceptible to barotrauma than birds, and that bat fatalities at wind turbines far outnumber bird fatalities at most sites, wildlife fatalities at wind turbines are now a bat issue, not a bird issue.”

Bats’ lungs, are balloon-like, with two-way airflow ending in thin flexible sacs surrounded by capillaries, and when outside pressure drops, those sacs will over-expand, bursting the capillaries around them.

Bats can reach ages of 30 or more and most have just one or two pups at a time, and not necessarily every year. “Slow reproductive rates can limit a population’s ability to recover from crashes and thereby increase the risk of endangerment or extinction,” ( Robert Barclay, also at the University of Calgary).

In the areas covered by wind turbines there are many species of bats eating thousands of insects—including many crop pests—per day as they go. So, having them wiped in one area could have very bad effects on our ecosystem.

A solution would be to reduce the pressure drop at wind turbines but that would severely limit their use or  to increase the speed at which turbine blades begin to rotate during the bats’ fall migration period because bats are more active when wind speeds are low.

    Sphere It