Frontiers in Behavioral Neuroscience (Mar 2016)

Weak broadband electromagnetic fields are more disruptive to magnetic compass orientation in a night-migratory songbird (Erithacus rubecula) than strong narrow-band fields

  • Susanne eSchwarze,
  • Susanne eSchwarze,
  • Nils-Lasse eSchneider,
  • Nils-Lasse eSchneider,
  • Thomas eReichl,
  • Thomas eReichl,
  • David eDreyer,
  • David eDreyer,
  • Nele eLefeldt,
  • Nele eLefeldt,
  • Svenja eEngels,
  • Svenja eEngels,
  • Neville eBaker,
  • P J Hore,
  • Henrik eMouritsen,
  • Henrik eMouritsen

DOI
https://doi.org/10.3389/fnbeh.2016.00055
Journal volume & issue
Vol. 10

Abstract

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Magnetic compass orientation in night-migratory songbirds is embedded in the visual system and seems to be based on a light-dependent radical pair mechanism. Recent findings suggest that both broadband electromagnetic fields ranging from ~2 kHz to ~9 MHz and narrow-band fields at the so-called Larmor frequency for a free electron in the Earth’s magnetic field can disrupt this mechanism. However, due to local magnetic fields generated by nuclear spins, effects specific to the Larmor frequency are difficult to understand considering that the primary sensory molecule should be organic and probably a protein. We therefore constructed a purpose-built laboratory and tested the orientation capabilities of European robins in an electromagnetically silent environment, under the specific influence of four different oscillating narrow-band electromagnetic fields, at the Larmor frequency, double the Larmor frequency, 1.315 MHz or 50 Hz, and in the presence of broadband electromagnetic noise covering the range from ~2 kHz to ~9 MHz. Our results indicated that the magnetic compass orientation of European robins could not be disrupted by any of the relatively strong narrow-band electromagnetic fields employed here, but that the weak broadband field very efficiently disrupted their orientation.

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