There is also something called barrotrauma, that is pulmonary embolism caused by a bat or bird flying behind the spinning blades. No contact is necessary and bats and sometimes birds can fly for quite a distance before hemorrhaging to death.
If you’ve been reading my blog for a while, you know I’m not concise. So here is my longer explanation.
My correspondent refers to this summary. You can find the full article on the second tab of that link. I don’t see a specific data, but do notice a 2008 copyright date.
I also found the article here: Barotrauma is a significant cause of bat fatalities at wind turbines.
The team of biologists explain wind turbines create a low-pressure area behind the turbine. Bats have superb echo locating ability so they can easily identify turbines and stay out of their way. The low-pressure area is undetectable for them.
When they fly through that low-pressure, the rapid change creates a significant difference in the pressure in their lungs compared to their immediate surroundings. That change causes a rapid expansion of the air in their lungs. The rapid change damages their particularly sensitive bodies. The hemorrhaging is so significant that the injury can be fatal.
The biologists explain several factors in a bat’s biology that create particular vulnerability to a rapid change in air pressure.
So that’s a great theory. It would explain why there are so many dead bats around wind turbines.
Do the biologists offer any evidence for their theory?
They went out to a turbine farm, gathered up a bunch of dead bats, and examined them to find the cause of death.
Let me quote them so you can see their detailed medical description:
Of 188 bats killed at turbines the previous night, 87 had no external injury that would have been fatal, for example broken wings or lacerations (Table 1). Of 75 fresh bats we necropsied in the ?eld, 32 had obvious external injuries, but 69 had haemorrhaging in the thoracic and/or abdominal cavities (Table 1). Twenty-six (34%) individuals had internal haemorrhaging and external injuries, whereas 43 (57%) had internal haemorrhaging but no external injuries. Only six (8%) bats had an external injury but no internal haemorrhaging
Let me rephrase their field autopsies:
- 6 – external injuries only
- 26 – external injuries and internal bleeding
- 43 – died due to internal bleeding
Of the bats who died so quickly that they immediately dropped to the ground, 91% had internal bleeding.
The portion of bats who are injured but live long enough to fly a few hundred or thousand feet before bleeding out is unknown.
I’m wondering if there is a better term to use than slice-and-dicer when referring to wind turbines. Because decompression is the cause of killing off lots of bats, slicer-dicer-crusher isn’t quite exact.
Slicer-dicer-decompressor may have too many syllables. Poor pithy score. (How’s that for a cool word?)
Friend of mine refers to the wind and solar industries as slice-dice-fry. Turning those verbs into nouns would give us slicer-dicer-fryer. I’ve also seen others refer to wind turbines as Cuisinarts ™. I doubt the trademark holder would appreciate that comment from those other pundits.
Will need to think about something more expansive than slice-and-dicer.