Influence of radar radiation on breeding biology of tits (Parus sp.).

Electromagnetic biology and medicine · 2007 · Mixed · Low evidence

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MixedLow evidencePaper 6450

Nest-boxes on the radar station area had different species occupancy patterns than controls: blue tits nested more in higher-exposed boxes while great tits occupied mainly lower-exposed boxes on the radar area (p < 0.01). No statistically significant differen…

Study snapshot

PublicationElectromagnetic biology and medicine · 2007

Study typeexposure_assessment

Reported directionMixed

Evidence ratingLow

Abstract

The aim of the present study is to observe the influence of long-term exposure to radar radiation on breeding biology of tits (Parus sp.), living and building nests around a military radar station, emitting pulse-modulated microwave radiation of 1,200-3,000 MHz. Two series of 36 nest-boxes each were located on the radar station area. Measurements of exposure were performed separately for each nest-box. Average power density (P(av), W/m(2)) and dose of exposure (W/m(2) x h) were recorded for each nest-box during 45 days. Control nest-boxes (N = 42) were located in other part of the same forests, free from radar radiation. The assessment of effects of radar exposure on breeding biology of tits included number of inhabited nest-boxes, number of eggs, and nestlings in the nest (Why not chick mortality?). Experimental nest-boxes were either exposed to relatively high levels of radiation (2.0-5.0 W/m(2), mean 3.41 +/- 1.38 W/m(2)) or an intermediate level of radiation that ranged from 0.1-2.0 W/m(2) (mean 1.12 +/- 0.84 W/m(2)). For control nest-boxes the exposure ranged from 0.001-0.01 W/m(2) (mean 0.0062 +/- 0.0007 W/m(2)). Only blue or great tits occupied all nest-boxes, used in the experiment. The number of nesting blue tits was higher in nest-boxes located on the radar station area than in the control boxes. In contrast, control nest-boxes were inhabited mainly by great tits. On the radar station area, blue tits nested in high exposed nest-boxes (67,0%) and great tit occupied mainly these boxes, which were exposed to low-level radiation (62,5%), the difference being statistically significant (p < 0.01). No statistically significant differences in other parameters of breeding biology (number of eggs per box, number of nestling per box) were observed between tits occupying exposed and control nest boxes. Results of the present study show that radar radiation generally does not lead to decrease of number of nesting tits, but may cause shifts in tits species living around the radar station. (But is the microhabitat, apart from the radiation level, around each nest box more likely to attract one species of tit or another?).

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 typeexposure_assessment

Effect directionmixed

PopulationTits (Parus sp.; blue tits and great tits) using nest-boxes in forests around a military radar station

Sample sizeNot supplied

Exposuremicrowave · 45 days (recorded during 45 days; described as long-term exposure)

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Outcomes measured

Number of inhabited nest-boxes
Number of eggs per nest-box
Number of nestlings per nest-box
Species distribution/occupancy (blue tit vs great tit)

Limitations

Observational design; potential confounding by microhabitat differences around nest-boxes (noted in abstract)
Chick mortality not assessed (raised in abstract)
Frequency range given (1,200–3,000 MHz) but no single frequency specified
Sample size for exposed nest-box occupancy not fully stated in abstract (two series of 36 nest-boxes mentioned; control N=42)

View raw extracted JSON

{
  "study_type": "exposure_assessment",
  "exposure": {
    "band": "microwave",
    "source": "military radar station",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "45 days (recorded during 45 days; described as long-term exposure)"
  },
  "population": "Tits (Parus sp.; blue tits and great tits) using nest-boxes in forests around a military radar station",
  "sample_size": null,
  "outcomes": [
    "Number of inhabited nest-boxes",
    "Number of eggs per nest-box",
    "Number of nestlings per nest-box",
    "Species distribution/occupancy (blue tit vs great tit)"
  ],
  "main_findings": "Nest-boxes on the radar station area had different species occupancy patterns than controls: blue tits nested more in higher-exposed boxes while great tits occupied mainly lower-exposed boxes on the radar area (p < 0.01). No statistically significant differences were observed between exposed and control nest-boxes for number of eggs per box or number of nestlings per box.",
  "effect_direction": "mixed",
  "limitations": [
    "Observational design; potential confounding by microhabitat differences around nest-boxes (noted in abstract)",
    "Chick mortality not assessed (raised in abstract)",
    "Frequency range given (1,200–3,000 MHz) but no single frequency specified",
    "Sample size for exposed nest-box occupancy not fully stated in abstract (two series of 36 nest-boxes mentioned; control N=42)"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "radar radiation",
    "pulse-modulated microwave",
    "1200-3000 MHz",
    "power density",
    "dose",
    "nest-box",
    "breeding biology",
    "blue tit",
    "great tit",
    "species shift"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.35,
      "reason": "Study involves exposure around a military radar station (environment near occupational/military source)."
    }
  ]
}

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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: 10.1080/15368370701357841
PubMed: 17886009

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