Anthropogenic electromagnetic noise disrupts magnetic compass orientation in a migratory bird

Abstract

Electromagnetic noise is emitted everywhere humans use electronic devices. For decades, it has been hotly debated whether man-made electric and magnetic fields affect biological processes, including human health. So far, no putative effect of anthropogenic electromagnetic noise at intensities below the guidelines adopted by the World Health Organization has withstood the test of independent replication under truly blinded experimental conditions. No effect has therefore been widely accepted as scientifically proven. Here we show that migratory birds are unable to use their magnetic compass in the presence of urban electromagnetic noise. When European robins, Erithacus rubecula, were exposed to the background electromagnetic noise present in unscreened wooden huts at the University of Oldenburg campus, they could not orient using their magnetic compass. Their magnetic orientation capabilities reappeared in electrically grounded, aluminium-screened huts, which attenuated electromagnetic noise in the frequency range from 50 kHz to 5 MHz by approximately two orders of magnitude. When the grounding was removed or when broadband electromagnetic noise was deliberately generated inside the screened and grounded huts, the birds again lost their magnetic orientation capabilities. The disruptive effect of radiofrequency electromagnetic fields is not confined to a narrow frequency band and birds tested far from sources of electromagnetic noise required no screening to orient with their magnetic compass. These fully double-blinded tests document a reproducible effect of anthropogenic electromagnetic noise on the behaviour of an intact vertebrate.

The quantum needle of the avian magnetic compass

“…However, very recent experiments (51), designed to replicate the earlier study (50), under much more stringently controlled conditions, failed to find specific effects at the Larmor frequency. In contrast, very weak broadband fields were found to disrupt the birds' magnetic compass orientation capabilities (51,52 Spin Relaxation and Magnetic Disorientation. The third major condition for the emergence of the spike is that the spin coherence times of the radicals should be longer than 1 μs, which in turn means that the librations of the radicals within their binding pockets must be of relatively low amplitude and not too sluggish.…”

“…Another approach would be to extend the behavioral experiments mentioned above in which broadband subnanotesla electromagnetic noise was found to prevent European robins from using their magnetic compass (52). If, for example, the birds' ability to orient was disrupted by 1-to 100-kHz but by not 1-to 10-kHz broadband noise, this would provide evidence for radical pair lifetimes and spin relaxation times in the range of 10−100 μs (50).…”

“…Because the spike only emerges when the coherence time exceeds 1 μs, its presence could explain why slow relaxation might have evolved. Moreover, it may now become possible to understand how radiofrequency fields, in particular broadband anthropogenic electromagnetic noise (sometimes called electrosmog) (52), interferes with the operation of the avian compass: not because all anisotropy is destroyed (21), but because the spike is attenuated. It remains to be seen, however, whether the spin relaxation can be slow enough to explain the reported effects (52).…”

High levels of maternally transferred mercury disrupt magnetic responses of snapping turtle hatchlings (Chelydra serpentina)

“…Overall, the emerging picture suggests that magnetic cues are an essential feature of animal spatial perception and behaviour, with a functionality going well beyond 'classical' navigational tasks ( Cervený et al, 2011;Dommer et al, 2008;Kimchi et al, 2004;Philips et al, 2010). Recently it has been shown that anthropogenic pollution in terms of electromagnetic background noise in and near cities are sufficient to disrupt such a magnetic sensor (Engels et al, 2014).…”

Recent progress in organic spintronics

“…In this context, a truly fascinating analogy can be made with the quantumbiological compass that is believed to enable organisms such as migratory birds to sense the Earth's magnetic field [38,39].…”