A machine learning analysis of wild lion audio reveals they have two roar types, not one. This insight might help detect where lions are declining.

As the Chinese Year of the Tiger draws to a close on 2nd February, TRAFFIC and WWF China are urging those concerned over the plight of wild Tigers to register their support at and make a Tiger roar.

Years ago, I was sitting in a friend’s living room with their cats when a lion documentary came on. A little bit of me wanted to change the channel – I worried the dainty pets felt a bit of “look what ...