title: Weak Broadband Electromagnetic Fields are More Disruptive to Magnetic Compass Orientation in a Night-Migratory Songbird (Erithacus rubecula) than Strong Narrow-Band Fields.
abstract: 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.
authors.affiliation: Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität OldenburgOldenburg, Germany; Research Centre for Neurosensory Sciences, University of OldenburgOldenburg, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Schwarze
authors.affiliation: Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität OldenburgOldenburg, Germany; Research Centre for Neurosensory Sciences, University of OldenburgOldenburg, Germany.
authors.forename: Nils-Lasse
authors.initials: NL
authors.lastname: Schneider
authors.affiliation: Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität OldenburgOldenburg, Germany; Research Centre for Neurosensory Sciences, University of OldenburgOldenburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Reichl
authors.affiliation: Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität OldenburgOldenburg, Germany; Research Centre for Neurosensory Sciences, University of OldenburgOldenburg, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Dreyer
authors.affiliation: Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität OldenburgOldenburg, Germany; Research Centre for Neurosensory Sciences, University of OldenburgOldenburg, Germany.
authors.forename: Nele
authors.initials: N
authors.lastname: Lefeldt
authors.affiliation: Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität OldenburgOldenburg, Germany; Research Centre for Neurosensory Sciences, University of OldenburgOldenburg, Germany.
authors.forename: Svenja
authors.initials: S
authors.lastname: Engels
authors.affiliation: Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory Oxford, UK.
authors.forename: Neville
authors.initials: N
authors.lastname: Baker
authors.affiliation: Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory Oxford, UK.
authors.forename: P J
authors.initials: PJ
authors.lastname: Hore
authors.affiliation: Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität OldenburgOldenburg, Germany; Research Centre for Neurosensory Sciences, University of OldenburgOldenburg, Germany.
authors.forename: Henrik
authors.initials: H
authors.lastname: Mouritsen
keywords: bird orientation; magnetic compass; magnetoreception; narrow-band electromagnetic field; radical pair mechanism; time-dependent electromagnetic fields