Study type: Medical/biological study (experimental study, observational study)

Behavior of free-ranging and captive American kestrels under electromagnetic fields. med./bio.

Published in: J Toxicol Environ Health A 2000; 59 (8): 597-603

Aim of study (acc. to author)

To determine the amount of time that wild reproducing American kestrels are exposed to electric fields and magnetic fields from power lines and to examine the behavior of captive kestrels exposed to electric fields and magnetic field similar to those from power lines.

Background/further details

For the first aim, wild pairs of kestrels were observed between 9 am and 4 pm. Time they spent in the wooden nest box (approximately 1 m below the power line) was determined. One pair of kestrels was observed during courtship (14 day long), six pairs during incubation and brood rearing (28 days each), and three pairs during the fledgling phase (10 days).
For the second aim, 56 pairs of American kestrels were randomly selected and the behavior was examined under different stages of reproduction: 1.) courtship (11 pairs control group, 9 pairs exposure group), 2.) incubation (10 pairs control group, 6 pairs exposure group) and 3.) brood rearing (4 pairs control group, 4 pairs exposure group).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: 71% - 91% of 24 h/day (estimated due to observed time)
wild kestrels
Exposure 2: 60 Hz
Exposure duration: 21 h/day for 95 days
captive kestrels

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Exposure duration 71% - 91% of 24 h/day (estimated due to observed time)
Additional info wild kestrels
Exposure setup
Exposure source
Distance between exposed object and exposure source 1 m
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1.2 µT - - - -
electric field strength 50 V/m - - - -

Exposure 2

Main characteristics
Frequency 60 Hz
Type
Exposure duration 21 h/day for 95 days
Additional info captive kestrels
Exposure setup
Exposure source
  • not specified
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 10 kV/m - - - -
magnetic flux density 30 µT - - - -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

Free-ranging American kestrels: Kestrels were exposed for 25% to 75% of the observed time. In a 24 hours-period, exposure of free living adult kestrels was estimated to range from 71% during courtship to 91% during incubation.
Captive American kestrels: During courtship, exposed female birds were significantly more active, more alert and perched on the roof more frequently compared to females from the control group. Exposed males were significantly more active than control males during courtship and incubation. During brood rearing, exposed females preened and rested significantly less often in comparison to the control group.
The authors conclude that exposure conditions of wild and captive American kestrels during the breeding saison were similar. The data indicate that exposure to electric fields and magnetic fields similar to those from power lines could influence the behavior of American kestrels.

Study character:

Study funded by

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