“Go now! The spoor is fresh!” Sandra Snelling, an operations manager for South African National Parks (SANParks), exclaimed, sending a squad of rangers on their next mission: tracking the poachers who had just killed a rhino in Kruger National Park.

It was October 2016, and I’d come to Skukuza, a SANparks post inside Kruger, to see how anti-poaching operations are carried out in the famed 7,500-square-mile preserve, where about 30 percent of the world’s estimated remaining 18,000 wild rhinos live.

Urgent dispatches are no surprise to these rangers, members of a special operations unit. Kruger, which encompasses land in Mpumalanga and Limpopo provinces, has long been a key target of poachers who kill rhinos for their horns, says Johan Jooste, former head