In the Portland Shipping Forecast last month we learnt how migrating birds use the iconic Bill as a landmark on their seasonal migration, an amazing feat of navigation that is possible in part due to the fact they have a molecule called Cryptochrome 4 in their eyes that helps them find north. Combined with their ability to recognise the constellations rotating around Polaris every night, they can cross-reference the stars with the earth’s magnetic field to pinpoint north more accurately than a compass.
Following on from these fascinating navigation skills, in this column I will explore how another species – the salmon – also uses magnetism on equally impressive journeys from the River Tyne to Norway and back! In a sense this is even
