The study was performed to test whether radiofrequency electromagnetic fields could be used as a method of preventing bats from death caused by collisions with wind turbines.
Four civil air traffic control radar stations, three military air traffic control radars and three weather radars were selected, each surrounded by heterogeneous habitat. At each radar station bat activity was recorded at three matched sites along an electromagnetic field gradient. Each radar station was surveyed three times with three different sampling points sampled on each occasion.
Exposure duration: continuous
reference article: Lin JC (1990) "Auditory perception of pulsed microwave radiation" in: Gandhi OP, ed (1990) "Biological effects and medical application of electromagnetic energy" Chapter 12 Englewood Cliffs, NJ: Prentice Hall pp 275-318
|electric field strength||2 V/m||minimum||measured||-||E > 2 V/m near the source in a distance < 200 m d:|
|electric field strength||2 V/m||maximum||measured||-||E < 2 V/m between 200 m and 400 m distance from the source d:|
|electric field strength||0 V/m||-||measured||-||distance from the source > 400 m|
Bat activity was significantly reduced in habitats exposed to an electromagnetic field strength of greater than 2 V/m when compared to matched sites registering electromagnetic field strength levels of zero (control sites). The reduction in bat activity was not significantly different at lower levels of electromagnetic field strength within 400 m of the radar.
The authors predict that the reduction in bat activity within habitats exposed to radiofrequency electromagnetic field irradiation may be a result of thermal induction and an increased risk of hyperthermia.