Magnetic activation in the brain of the migratory northern wheatear (Oenanthe oenanthe)
Behavioural and neurobiological evidence suggests the involvement of the visual and trigeminal sensory systems in avian magnetoreception. The constantly growing array of new genetic approaches becoming available to scientists would bear great potential to contribute to a generally accepted understanding of the mechanisms underlying this ability, but would require to breed migratory birds in captivity. Here we show that the transcontinental night-migratory Northern Wheatear (Oenanthe oenanthe), which is currently the only migratory songbird successfully being bred in reasonable numbers in captivity, shows magnetic-field-induced neuronal activation in the trigeminal brainstem areas receiving their input through the ophthalmic branch of the trigeminal nerve. In addition, preliminary data indicate night vision-triggered activation in the anterior visual forebrain. This brain area could represent the same brain region, which has previously been named “Cluster N” and shown to be involved in processing magnetic compass information in European Robins. Thus, based on brain activation data, both visually and trigeminally mediated magnetic senses known from other birds seem to exist in Northern Wheatears. This makes this species a potentially excellent model species for future genetic research on magnetoreception in migratory birds.