A field study was performed on kestrels to compare chicks from pairs nesting on high voltage power lines versus those nesting in control sites in similar habitats.
Nesting on high voltage power line towers exposes birds to electric and magnetic fields for long periods. Nestlings are exposed from their development in ovo until fledging. This is a critical period for them, because the quality of the environment may affect their fitness at adulthood.
The study was carried out during the breeding season in the year 2000 in an area aoround Rome. Nest-boxes for kestrels have been attached to high voltage power line towers. 44 nest-boxes were included in the study: 28 were exposed and 16 were control nests (attached at abandoned transmission towers, non-electric pylons or abandoned buildings). Different numbers of nests were used to study different parameters.
Exposure duration: breeding season of the year 2000
|Exposure duration||breeding season of the year 2000|
|electric field strength||480 V/m||-||measured||-||on the ground below a 150 kV line|
|electric field strength||2,600 V/m||maximum||measured||-||inside the nest at a 150 kV line|
|magnetic flux density||4 µT||-||measured||-||on the ground under a 150 kV line|
|magnetic flux density||7.9 µT||-||measured||-||in the nest at a 150 kV line|
|magnetic flux density||1.37 µT||minimum||measured||-||-|
|magnetic flux density||8.63 µT||mean||measured||-||-|
|magnetic flux density||25.16 µT||maximum||measured||-||-|
None of the variables differed between exposed and control nestlings. The data suggest that exposure to magnetic fields produced by high voltage power lines during the embryonic and post-hatching period (until fledging) does not have significant short-term physiological effects on kestrel nestlings.