On New Year’s Day, Merlin, a springer spaniel belonging to Daniel Horsley, ran away from his front garden in Cumbria after appearing to suffer some kind of fit. One hundred people were involved in a search involving drones and thermal-imaging cameras. And, 16 hours later, Merlin found his own way home, quite unharmed. If nothing else, all these helpers united by a lost dog confirmed one thing. Quite simply: animals bring people together.
But what no one seemed to realise is this. No human technology yet invented can match the uncanny homing abilities of dogs. A century ago, a collie cross in the US was busy showing the rest of them up. In August 1923, the Brazier family lost Bobbie on their holiday in Indiana; and in February 1924 he was back home with them in Silverton, Oregon. All the evidence indicates he walked the whole way, about 3,000 miles, over six months through the intense winter cold. His endurance alone was formidable. But how did he know where to go?
