The Great Moose Migration has become a ‘slow TV’ sensation, keeping audiences worldwide glued to the beasts’ epic trek – even if they’re rarely spotted on screen. We go behind the scenes with its makers The Great Moose Migration has become a ‘slow TV’ sensation, keeping audiences worldwide glued to the beasts’ epic trek – even if they’re rarely spotted on screen. We go behind the scenes with its makers O n a crisp bright early spring afternoon on a small uninhabited island in the Ångerman river