 On NewsHour now, we have a story of endurance from the animal kingdom. Two lions have been filmed making what looks to have been a record-breaking one and a half kilometre swim across a crocodile-infested channel in Uganda. Their feet says a lot about their determination to get out of the way of humans and also determination to mate. As Craig Packer explains, he is founder of the Lion Centre at the University of Minnesota in the US. He's been analysing what happened.