A decade ago, up to 1,000 of the apex predators lived in one South African bay. Now they have gone, fleeing from killer whales. But the gap they have left creates problems for other species

The first carcass of a great white, a small female, washed up in South Africa on 9 February 2017. The 2.6-metre-long body had no hook or net marks, ruling out human involvement. Whatever had killed her had vanished. So too had all the other great white sharks in Gansbaai on the Western Cape, Dr Alison Towner noticed.

“We had several sharks acoustically tagged, and later realised three had moved as far as Plettenberg Bay and Algoa Bay, more than 500km [300 miles] east,” says the Rhodes University marine biologist.

Juan Guillermo Garcés had a brush with death while burning jungle for cattle pasture – now he runs a nature reserve in Colombia where more than 100 new species have been discovered

• Words and photographs by Anastasia Austin and Douwe den Held

Juan Guillermo Garcés remembers coming face to face with death at age 17. Smoke filled the air, choking his lungs. The temperature rose and Garcés struggled to see through the haze. Panic set in as he watched monkeys, snakes, lizards and birds desperately trying to escape the flames surrounding them.

Garcés and his brother started the fire that nearly killed them to clear a large stretch of land. But when the wind suddenly changed direction, they found themselves locked in. The brothers survived, but the fire destroyed the little remaining patch of virgin forest on the family’s 2,500-hectare (6,200-acre) ranch, nestled along Colombia’s Magdalena River. Experiencing firsthand what the animals and plants endured was a turning point for Garcés.