Migratory birds can extract positional information from magnetic inclination and magnetic declination

Proceedings of the Royal Society B: Biological Sciences · 2024 · Unclear · Insufficient evidence

← Research stream

UnclearInsufficient evidencePaper 64

Study snapshot

PublicationProceedings of the Royal Society B: Biological Sciences · 2024

Study typeother

Reported directionUnclear

Evidence ratingInsufficient

Abstract

Migratory birds can extract positional information from magnetic inclination and magnetic declination alone Packmor F, Kishkinev D, Zechmeister T, Mouritsen H, Holland RA. Migratory birds can extract positional information from magnetic inclination and magnetic declination alone. Proc Biol Sci. 2024 Nov;291(2034):rspb20241363. doi: 10.1098/rspb.2024.1363. Abstract Migratory birds are able to navigate over great distances with remarkable accuracy. The mechanism they use to achieve this feat is thought to involve two distinct steps: locating their position (the 'map') and heading towards the direction determined (the 'compass'). For decades, this map-and-compass concept has shaped our perception of navigation in animals, although the nature of the map remains debated. However, some recent studies suggest the involvement of the Earth's magnetic field in the map step. Here, we tested whether migratory songbirds, Eurasian reed warblers (Acrocephalus scirpaceus), can determine their position based on two magnetic field components that are also associated with direction finding, i.e. magnetic inclination and magnetic declination. During a virtual magnetic displacement experiment, the birds were exposed to altered magnetic inclination and magnetic declination values that would indicate a displacement from their natural migratory corridor, but the total intensity of the field remained unchanged, creating a spatial mismatch between these components. The response was a change in the birds' migratory direction consistent with a compensatory re-orientation. This suggests that birds can extract positional as well as directional information from these cues, even when they are in conflict with another component of the magnetic field. It remains to be seen whether birds use the total intensity of Earth's magnetic field for navigation. Open access paper: royalsocietypublishing.org

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 directionunclear

PopulationMigratory songbirds (Eurasian reed warblers, Acrocephalus scirpaceus)

Sample sizeNot supplied

ExposureNot supplied

Evidence strengthInsufficientConfidence: 66% · Peer reviewed: yes

Main findings

In a virtual magnetic displacement experiment where magnetic inclination and declination were altered while total field intensity was kept unchanged, birds changed their migratory direction in a manner consistent with compensatory re-orientation. The authors interpret this as evidence that birds can extract positional information from magnetic inclination and declination even when these cues conflict with another magnetic field component (total intensity).

Outcomes measured

Change in migratory direction
Compensatory re-orientation in response to altered magnetic inclination and declination

Limitations

Sample size not reported in the provided abstract/metadata
Exposure parameters beyond altered inclination/declination (e.g., exact field values, duration) not reported in the provided abstract/metadata
It remains unresolved whether birds use total magnetic field intensity for navigation (as stated by the authors)

View raw extracted JSON

{
  "study_type": "other",
  "exposure": {
    "band": null,
    "source": "Earth's magnetic field (altered magnetic inclination and declination in a virtual magnetic displacement experiment)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Migratory songbirds (Eurasian reed warblers, Acrocephalus scirpaceus)",
  "sample_size": null,
  "outcomes": [
    "Change in migratory direction",
    "Compensatory re-orientation in response to altered magnetic inclination and declination"
  ],
  "main_findings": "In a virtual magnetic displacement experiment where magnetic inclination and declination were altered while total field intensity was kept unchanged, birds changed their migratory direction in a manner consistent with compensatory re-orientation. The authors interpret this as evidence that birds can extract positional information from magnetic inclination and declination even when these cues conflict with another magnetic field component (total intensity).",
  "effect_direction": "unclear",
  "limitations": [
    "Sample size not reported in the provided abstract/metadata",
    "Exposure parameters beyond altered inclination/declination (e.g., exact field values, duration) not reported in the provided abstract/metadata",
    "It remains unresolved whether birds use total magnetic field intensity for navigation (as stated by the authors)"
  ],
  "evidence_strength": "insufficient",
  "confidence": 0.66,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "migratory birds",
    "navigation",
    "magnetoreception",
    "magnetic inclination",
    "magnetic declination",
    "virtual magnetic displacement",
    "Eurasian reed warbler"
  ],
  "suggested_hubs": []
}

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: 10.1098/rspb.2024.1363
PubMed: Not supplied

Read the original paper →

Related papers

← Back to the Research Library