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

Journal of toxicology and environmental health. Part A · 2000 · Mixed · Low evidence

← Research stream

MixedLow evidencePaper 5346

Study snapshot

PublicationJournal of toxicology and environmental health. Part A · 2000

Study typeother

Reported directionMixed

Evidence ratingLow

Abstract

Wild birds, particularly raptors, commonly use electrical transmission structures for nesting, perching, hunting, and roosting. Consequently, birds are exposed to electromagnetic fields (EMFs). The amount of time that wild reproducing American kestrels (Falco sparverius) were exposed to EMFs was determined, and the effects of EMFs on the behavior of captive reproducing kestrels were examined. Wild kestrels were exposed to EMFs for 25% to 75% of the observed time. On a 24-h basis, estimated EMF exposure of wild kestrels ranged from 71% during courtship, to 90% during incubation, similar to that experienced by captive kestrels (88% of a 24-h period). Additionally, captive kestrels were exposed to EMF levels experienced by wild kestrels nesting under 735-kV power lines. Captive EMF females were more active, more alert, and perched on the pen roof more frequently than control females during courtship. EMF females preened and rested less often during brood rearing. EMF male kestrels were more active than control males during courtship, and more alert during incubation. Increased activity of kestrels during courtship may be linked to changes in corticosterone, but likely not melatonin. Observed behavioral changes were unlikely to directly result in the better growth of nestlings and fledging success, or poorer hatching success, of the EMF group, as previously reported. Behavioral changes of captive EMF kestrels may be observed in wild kestrels.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeother

Effect directionmixed

PopulationAmerican kestrels (Falco sparverius), wild free-ranging reproducing birds and captive reproducing birds

Sample sizeNot supplied

ExposureELF · Wild kestrels exposed 25%–75% of observed time; estimated 24-h exposure 71% (courtship) to 90% (incubation). Captive kestrels exposed 88% of a 24-h period.

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Wild reproducing kestrels were estimated to be exposed to EMFs for a substantial portion of time (25%–75% of observed time; 71%–90% on a 24-h basis depending on breeding stage). Captive females exposed to EMFs showed increased activity/alertness and more frequent perching on the pen roof during courtship, and preened/rested less during brood rearing; exposed males were more active during courtship and more alert during incubation. The abstract states these behavioral changes were unlikely to directly explain previously reported differences in growth/fledging success or hatching success in the EMF group.

Outcomes measured

Time spent exposed to EMFs (wild kestrels)
Behavioral activity/alertness/perching (captive kestrels)
Preening and resting behavior (captive kestrels)
Nestling growth and fledging success (referenced as previously reported)
Hatching success (referenced as previously reported)
Corticosterone (hypothesized link)
Melatonin (hypothesized not linked)

Limitations

Sample size not reported in the abstract/metadata
EMF field characteristics (e.g., field strength, frequency) not provided in the abstract
Some outcome interpretations rely on previously reported reproductive outcomes rather than results detailed here
Mechanistic links (corticosterone/melatonin) are speculative in the abstract

View raw extracted JSON

{
  "study_type": "other",
  "exposure": {
    "band": "ELF",
    "source": "electrical transmission structures / 735-kV power lines",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "Wild kestrels exposed 25%–75% of observed time; estimated 24-h exposure 71% (courtship) to 90% (incubation). Captive kestrels exposed 88% of a 24-h period."
  },
  "population": "American kestrels (Falco sparverius), wild free-ranging reproducing birds and captive reproducing birds",
  "sample_size": null,
  "outcomes": [
    "Time spent exposed to EMFs (wild kestrels)",
    "Behavioral activity/alertness/perching (captive kestrels)",
    "Preening and resting behavior (captive kestrels)",
    "Nestling growth and fledging success (referenced as previously reported)",
    "Hatching success (referenced as previously reported)",
    "Corticosterone (hypothesized link)",
    "Melatonin (hypothesized not linked)"
  ],
  "main_findings": "Wild reproducing kestrels were estimated to be exposed to EMFs for a substantial portion of time (25%–75% of observed time; 71%–90% on a 24-h basis depending on breeding stage). Captive females exposed to EMFs showed increased activity/alertness and more frequent perching on the pen roof during courtship, and preened/rested less during brood rearing; exposed males were more active during courtship and more alert during incubation. The abstract states these behavioral changes were unlikely to directly explain previously reported differences in growth/fledging success or hatching success in the EMF group.",
  "effect_direction": "mixed",
  "limitations": [
    "Sample size not reported in the abstract/metadata",
    "EMF field characteristics (e.g., field strength, frequency) not provided in the abstract",
    "Some outcome interpretations rely on previously reported reproductive outcomes rather than results detailed here",
    "Mechanistic links (corticosterone/melatonin) are speculative in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "American kestrel",
    "Falco sparverius",
    "raptors",
    "power lines",
    "735-kV",
    "electromagnetic fields",
    "ELF",
    "behavior",
    "courtship",
    "incubation",
    "brood rearing"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.32,
      "reason": "Study concerns exposure near high-voltage transmission lines; closest available hub relates to structured exposure contexts (though this is wildlife rather than human occupational exposure)."
    }
  ]
}

AI can be wrong. Always verify against the paper.

AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1080/009841000156619
PubMed: 10839495

Read the original paper →

Related papers

← Back to the Research Library