The jaguar known here as Tobuna saunters along nonchalantly, undisturbed by the humans observing her with fascination. The 14-year-old female investigates the inside of a hollow tree trunk and finds a piece of pork that her handler had left for her there. Then she trots off and agilely climbs to a tree platform built for her in her octagonal, wire-fenced confinement area of 1,200 square meters.

“Since she arrived here last May, she has lost two or three kilos thanks to the activity,” says her handler, David Diago, an employee of the San Alonso Reserve a vast area of conserved land in northeastern Argentina’s Esteros del Iberá, the second largest wetland region of South America. “Compared to her previous life in a zoo cage, she’s now in a five-star hotel.”

Tobuna’s new turf is a small corner of the Experimental Jaguar Breeding Center (CECY), a complex at San Alonso featuring seven confinement areas of various sizes for jaguars that will be bred and released into the Esteros del Iberá, which is located in the Argentine province of Corrientes. Tobuna is the first jaguar (Panthera onca) seen since the mid-20th century in Corrientes, which borders, Brazil, Paraguay and Uruguay. Born and raised in captivity, she was donated to the reserve by the Batán Zoo, located 420 kilometers (260 miles) south of the Argentine capital of Buenos Aires. Her role will now be to produce offspring that the center hopes will become the first free-roaming jaguar here since the species disappeared from this province, largely due to expanded cattle ranching and hunting in the region.

San Alonso, a 10,000-hectare (25,000-acre) former cattle ranch, is only reachable by boat or plane on account of its location deep in the Esteros del Iberá. The Esteros, as they’re called, cover 1.3 million hectares (3.2 million acres), or approximately 15% of Corrientes province’s land area. They encompass grasslands, swamps, lakes and some woodlands, and are home to an extraordinary range of plant and animal species. A boat ride to the reserve underscores the point, revealing two types of caiman (Caiman latirostris and Caiman yacare), marsh deer (Blastocerus dichotomus), capybara (Hydrochaeris hydrochaeris), two types of foxes (Cerdocyon thous and Lycalopex gymnocercus) and an enormous variety of birds.

Nevertheless, various animal species disappeared here over the years in addition to the jaguar, which is known by the name given it by the region’s indigenous Guaraní people: yaguareté. Among the other mammals to vanish locally are the giant anteater (Myrmecophaga tridactyla), collared peccary (Pecari tajacu), South American tapir (Tapirus terrestris) and pampas deer (Ozotoceros bezoarticus). The causes, aside from ranching and hunting, included the appearance of animal traffickers, says Spanish biologist Ignacio Jiménez Pérez, who has been conducting research in the Esteros del Iberá for nine years.

Jiménez (see Q&A—this issue) is general coordinator of species-reintroduction programs here for the Conservation Land Trust, a charitable foundation created at the outset of the 1990s by U.S. entrepreneur Douglas Tompkins, co-founder of the Esprit and The North Face clothing lines. Headquartered in San Francisco, California, the trust has undertaken large-scale land conservation initiatives in the Esteros and is underwriting the project to reintroduce the jaguar as well as other of the animals that vanished in this vast wetland region.

Though the trust also has funded major land-conservation efforts in Chile and the south of Argentina, its wildlife-reintroduction efforts focus exclusively on the Esteros del Iberá. Those efforts began bearing fruit in 2007 with the return to the wild here of the giant anteater, which can measure two meters in length thanks in part to its long tail and snout. In March of 2007, Corrientes province Gov. Ricardo Colombi turned loose the first pair of these anteaters in the Esteros del Iberá.

Since then, dozens more giant anteaters have been donated to the reserve by individuals and rescue centers that have raised them in other northern Argentine provinces, usually after hunters had killed their mothers. All have been returned to the wild. The Conservation Land Trust estimates that 68 to 78 giant anteaters are now living in the Esteros, and that 27 of them were born in the wild. The reintroduced anteaters initially are monitored through the use of radio collars and are given food supplements consisting of a mix of fruits, yogurt and a variety of cat food. Most now no longer have collars and sustain themselves on their own.

The second animal reintroduced by the center was the pampas deer, whose return to the Esteros del Iberá was begun in 2009. The deer’s population in the area now numbers 80 to 110, of which about 50 were born in the wild. And in May, the center’s scientists released eight collared peccaries, which had been donated to the center by a wildlife reserve run by the Natural Sciences School at the National University of Tucumán Province. Next—sometime before the end of the year—the center plans to begin releasing tapirs into the wild.

None of the center’s work has attracted as much attention as its planned reintroduction of the jaguar, which is near extinction in Argentina, with an estimated 200 of the animals still living in the wild nationwide. In 2001, the Argentine Congress declared jaguars a “natural monument,” effectively extending the country’s strongest legal protection to the animal.

Most of Argentina’s jaguars are believed to live in the northern provinces of Misiones, Salta and Jujuy. The animal’s disappearance in the Esteros del Iberá is believed to have spurred growth there in the populations of herbivores such as the capybara, the world’s largest rodent. Scientists and government authorities in Corrientes hope the reintroduced jaguars not only will help bring the wetland’s animal populations in balance, but also will attract tourists in the same way jaguars draw visitors to the enormous Pantanal wetland in Brazil. “Here in the Iberá, the resource is the fauna,” says Jiménez. “People here no longer see the question of animals as a matter of conservation but of economic development. And the jaguar will generate many resources, just as the glaciers in Calafate or the whales off Peninsula Valdés do.”

The reintroduction project here has a strong advocate in George Schaller, a German naturalist known internationally for his studies of gorillas and feline species in Africa. Schaller visited Corrientes province in 1975. Recalling that visit during a trip to Corrientes in 2012, Schaller told the Argentine media: “I was in the Brazilian Pantanal doing a marsh-deer census and wanted to see what the situation was in Iberá. In a small plane we flew over 1,000 kilometers of the wetlands and I saw 17 marsh deer. It wasn’t a complete count, of course, but I was impressed because this fantastic place was practically devoid of animals.”

Jiménez, the species-reintroduction coordinator, says the jaguar center will obtain two more male jaguars and a female, which—counting Tobuna—will give it two pairs. These jaguars will never be freed, since they are deemed incapable of living in the wild. Their role will be to produce offspring, which will live in ever-larger enclosures until their release into the Esteros del Iberá.

After the female jaguars give birth in their 1,200-square-meter enclosures, they and their offspring will be moved to larger confinement areas of 1.5 hectares (3.7 acres), in which animals such as foxes and capybara will eventually be introduced so the young jaguars can learn to hunt, though they will be fed meat as well. Finally, the offspring will live for approximately six months without their mothers in a far bigger 30-hectare (74-acre) confinement area that has been built to provide near-wild conditions before the animals are set loose in the Esteros.

Though enclosed, the larger area will encompass key components of the Esteros landscape, including grassland, marsh, water bodies and woods. It will also contain capybara, deer and other native animal species that the new generation of jaguars will be expected to prey on to meet their full dietary needs.

Fencing off the areas in which jaguars will be raised has been a feat in itself, involving the installation of 300 tons of metal posts donated by an oil-transport company. The posts were brought to the jaguar center at San Alonso by raft and, once on land, drawn by oxen because the ground in many places was too wet for tractors. They were cut and welded over a period of weeks in San Miguel, a town of 4,000 about 60 kilometers (37 miles) from the center.

The reintroduction project comes against a backdrop of conservation efforts in the Esteros del Iberá. Those efforts date from 1983, when the Corrientes provincial legislature passed a law extending natural-reserve status to 1.3 million hectares (3.2 million acres) of the Esteros. Over half of the new reserve comprised private property owned by agricultural operators. The province hired park guards—including former hunters who know the wetlands well—and animal populations slowly began to recover.

Another provincial law enacted in 1993 made a park out of a 550,000-hectare (1.4-million-acre) portion of the Esteros del Iberá reserve that belonged to the provincial government. Soon after, tourism investment got underway in Carlos Pellegrini, a town of under 1,000 residents that serves as a point of entry to the wetlands. Tourism, which was virtually nonexistent in the region in the 1990s, now amounts to some 30,000 visitors annually, according to Corrientes province’s Tourism Ministry.

Douglas Tompkins and his wife Kris, a former CEO of the Patagonia outdoor-clothing company, became acquainted with the Esteros del Iberá in 1997, when the Argentine government invited them to tour the region. The Conservation Land Trust at the time had brought some 400,000 hectares of land under protection in Chile, and was looking to embark on conservation projects in Argentina.

The Esteros del Iberá struck the Tompkinses as an ideal focal point for ecological restoration, habitat protection and reintroduction of native animal species. In the period 1997 to 2002, Conservation Land Trust bought 150,000 hectares (370,000 acres) of Iberá land previously used for ranching, all of it bordering the provincial park. From the start, Tompkins let it be known that once the trust’s land was restored to ecological health it would be donated to the Argentine government in the expectation it would be designated as a national park. One condition set by Tompkins, and which Corrientes authorities do not appear eager to agree to, is that the province eventually donate the Iberá land it holds to the future national park. If the province were to do so, it would help create one of Argentina’s largest national parks, at 700,000 hectares (1.7 million acres).

Early headwinds

As in Chile, Tompkins encountered public doubts about his motives. Some critics objected to the prospect of a foreigner owning one of Argentina’s prime water sources and questioned the sincerity of his offer to donate the trust’s land to the government for a national park. Also as in Chile, however, he responded by pushing ahead. In 2002 the Conservation Land Trust and Kris Tompkins’s foundation, Conservación Patagónica, bought a former sheep farm of 66,000 hectares (163,000 acres) in the Patagonian province of Santa Cruz and donated it to the government to allow the creation, in 2004, of a national park, Monte León.

Throughout, such projects have been driven by the view that biodiversity loss is the prime threat facing the planet. “The crisis of extinction is the mother of all crises,” Tompkins wrote in a book published last year by the trust. “It should be addressed with even more vigor than climate change, even though both should be confronted simultaneously.”

To that end, Conservation Land Trust created the species-reintroduction program at the Esteros del Iberá. Says Ignacio Jiménez: “To be complete and of genuine quality, the future national park should have all of its species.”

In September of 2012, the Conservation Land Trust brought international conservation experts as well as provincial and federal environmental and wildlife officials to the Esteros to discuss the possibility of reintroducing the jaguar. Among those present was Schaller, the German naturalist. “The return of the jaguar can generate a great increase in tourism in the Iberá, as was the case with the Pantanal,” Schaller said during his 2012 visit. “When I worked there [in the Brazilian Pantanal] in the early 70s, the jaguars were very timid and one would never see them. Then came the visitors and inns were built on ranches. Today the tourists move around by boat and the jaguars are accustomed to seeing them. It is a marvelous experience for the visitor.”

Scientific approach praised

Some 30 Argentine and Brazilian biologists and veterinarians have collaborated in the project. One of them, Mario Di Bitetti, director of the Institute of Subtropical Biology at Argentina’s University of Misiones, says he is impressed by the strong scientific underpinnings of the work. He also praises the goal—to restore an ecosystem thrown out of balance by the disappearance of its apex predator. Says Di Bitetti: “There are not many precedents in the world for the reintroduction of large carnivores, so we’ll know within 10 years or so whether the project is successful.”

Biologist Carlos de Angelo conducted aerial surveys of the Iberá during a 12-month period in 2013-14. “A great predator needs prey to eat and refuges where it can stalk its prey,” he says. “These two requirements make for a secure place, so that over time the circumstances that extinguished it will not extinguish it once again. The Iberá has these two things.” De Angelo estimates the Esteros could support 100 jaguars, half again as many jaguars as are estimated to be living in the wild in Argentina.

Social repercussions of the reintroduction are being explored as well. Flavio Caruso, a biologist at the National University of the Northeast, which is located in the city of Corrientes, the provincial capital, surveyed 450 residents of the province. Some 90% of the participants, who included residents of the capital and of cities and towns near the Esteros, supported reintroduction of the jaguar.

Indeed, there is other evidence that the project has gained traction. Numerous businesses in San Miguel these days display decals bearing images of jaguars, anteaters and pampas deer along with the tagline: “Corrientes is going back to being Corrientes.”