We all know that birds fly south for the winter ... unless you're in the southern hemisphere, then they fly north. But for for a migrating bird it isn't a simply case of flying from A to B.  A bird not only has to find its way but build up the strength to make marathon flights, and no two birds perform their migration in the same way. So join me this week as in dig into one of the most remarkable bird behaviour. NotesThe  world's largest dyke: https://en.wikipedia.org/wiki/Saemangeum_Seawall Operation Migration: https://en.wikipedia.org/wiki/Operation_MigrationNo fish besmirches my brand: https://www.youtube.com/watch?v=h4pxLHG0Wzs&ab_channel=BBCEarth