Radiofrequency disorientation in migratory birds: radical pairs or a separate sensory system?

Journal article

Alongside other directional cues, migratory songbirds use the Earth’s magnetic field to help them navigate the hundreds or thousands of kilometres between their breeding and overwintering sites. If it seems surprising that an animal can extract information from a magnetic field a hundred times weaker than a small refrigerator magnet, it should be astounding that this ability can be disrupted by radiofrequency magnetic fields thousands of times weaker still. Magnetic fields with strengths between 1 and 100 nT and frequencies between 0.1 and 100 MHz have been found to prevent captive night-migratory songbirds from orienting in the geomagnetic field (25−65 µT, depending on geographic location). Remarkably, the frequency dependence of this disruption agrees closely with predictions for radical pairs in cryptochrome (the leading hypothesis for the mechanism of the avian magnetic compass), whereas the extraordinarily weak fields that cause disorientation are difficult to reconcile with conventional radical-pair theory. This perspective examines the evidence for radiofrequency-induced disorientation and its relationship to the cryptochrome hypothesis. It concludes by considering a suggestion that birds may possess a distinct radiofrequency-sensitive system based on electromagnetic induction. 

Authors: Hore, PJ

• Publication status: Accepted
• Peer review status: Peer reviewed
• Publisher: China Science Publishing & Media Ltd
• Journal: Zoological Applications More from this journal
• Language: English