El Impenetrable national park, home to thousands of charismatic plants, flowers and animals, including jaguars.

How to rewild a country: the story of Argentina

It began with a philanthropic couple buying a swamp but has become one of the world’s boldest experiments in restoring degraded habitats, bringing wildlife and landscapes back from the brink

Chapter one

The return of the jaguar

It took about three seconds for piranhas to devour part of her left foot, biologist Deborah Abregü recalls, as we sit waiting for pizzas to cook on an open fire in Argentina’s El Impenetrable national park. The 30-year-old scientist, who works on a jaguar reintroduction programme for the NGO Rewilding Argentina, was getting out of a kayak last year when the water was at its hottest and the fish were most aggressive. The piranhas swarmed, she said, showing me a photo of the resulting wounds from the rare attack.

“I used to feel bad catching piranhas to feed the jaguars. Not any more,” Abregü says, flicking through more images on her phone of the live caymans that she and the other biologists trap for jaguar cubs Nalá and Takajay to teach them how to fend for themselves in the wild.

Covering an area one-and-a-half times the size of California, the dense dry forests of the Gran Chaco stretch from southern Bolivia to northern Argentina and western Paraguay. Its name – which means “hunting land” in Quechua – probably refers to the thousands of charismatic plants and animals found in the arid La Plata river basin: armadillos, maned wolves and the “drunken stick” tree, whose bulging spiky trunks and tiny leaves help it cling on to water in the driest months.

While South America’s second-largest forest receives a fraction of the attention dedicated to the Amazon, it is no less threatened. From 1985 to 2013, a fifth was lost to farmland and cattle ranching, according to Nasa data. The trend has intensified, making it one of the most at-risk ecosystems on the planet…