Niokolo-Koba National Park, SenegalThe squeals of a warthog blast from loudspeakers and echo through the trees as Kris Everatt tries to lure in a lion to be darted and radio-collared. He pauses the recorded cries, and the team goes back to waiting sleepily in the truck.

Seemingly out of nowhere, we hear paws crunching through dry leaves close by. We’ve been here all night, staking out the bait, but are suddenly very awake.

Then, silence. Everatt, a Canadian biologist with the wild cat conservancy Panthera who has worked in Africa for more than a decade, has the vacant, intent expression of someone trying to see with his ears.

To my surprise, he begins huffing the deep grunting purrs of a contented lion. The ruse works, and