In January 2021, Argentina released three jaguars into the Iberá wetlands, a region where the species had been locally extinct for 70 years. Scientists gave the reintroduction project a decade to prove itself. Four years later, the population had grown beyond expectations, with wild births occurring for the first time in generations.

The Iberá wetlands span 13,000 square kilometers in Corrientes Province in northeastern Argentina. The region contains floodplains, lakes, and subtropical forests, and supports more than 4,000 species. This includes 350 bird species and 60 reptile species. Nearly a third of Argentina’s vertebrates live within the wetlands.

The ecosystem formed about 1.8 million years ago when the Paraná River changed course, leaving behind an inland sea. Species evolved together through that period into an interconnected system, with the jaguar at the top of the food chain.

The last confirmed jaguar sighting in Iberá was in 1953. Over the following decades, commercial hunting and conflicts with cattle ranchers eliminated the species from the region deliberately and completely. Ranchers killed jaguars to protect herds. Caiman were hunted for their skins, giant otters for their fur, and giant anteaters, collared peccaries, and Pampas deer also disappeared from the area. The red-and-green macaw went locally extinct more than a century ago.

The removal of top predators had measurable effects on the ecosystem. Capybaras, the world’s largest rodents, graze six to nine pounds of vegetation daily. Without predators, their populations grew unchecked, and they grazed open areas constantly. Researchers recorded 129 capybaras per square kilometer on one island. Studies showed that areas grazed by capybaras had significantly less plant biomass than fenced areas where they could not access vegetation. Without the pressure of a predator, capybaras had no reason to avoid open water edges or limit grazing time. Birds lost the tall grass cover they needed for nesting, and insects lost shelter.

For nearly 50 years after the last jaguar disappeared, no large-scale initiative addressed this decline. The first significant effort came from an unexpected source: Doug Tompkins, co-founder of The North Face and Esprit. In the late 1980s, Tompkins left the apparel industry and moved to South America with his wife, Kris Tompkins, former CEO of Patagonia.

In 1997, Tompkins flew over the Iberá wetlands and was struck by the absence of wildlife. He began buying degraded ranch land through a conservation fund, eventually acquiring about 150,000 hectares. His purchases drew suspicion in Argentina, with some media outlets speculating about his motives. In the town of Colonia Carlos Pellegrini, resident Jorge Uridó heard the same rumors as everyone else.

Tompkins died in a kayaking accident in December 2015. Kris Tompkins continued the work. The land was eventually donated to help create Iberá National Park, about 700,000 hectares of protected habitat, one of the largest private conservation gifts in South American history.

The remaining wild jaguars in Argentina numbered only about 200, scattered across the Gran Chaco in the northwest. The gene pool was small and fragmented, making inbreeding a long-term risk. Obtaining genetically viable animals required years of international coordination, permits, and biosafety reviews.

In 2012, Rewilding Argentina built a breeding center on San Alonso Island, large enough for jaguars to hunt live prey within their enclosures. The first jaguars arrived in 2015, but they were too old, too closely related, and too far from wild behavior to breed reliably. The program stalled for years.

In 2019, a female jaguar named Mariua arrived. She had been found as an orphaned cub in Brazil after hunters shot her mother. A rescue center near Brasília raised her until she was old enough to travel. She adapted to the breeding program more quickly than previous animals, and within two years gave birth to two cubs, Karai and Porá.

The program maintained strict protocols: minimal human contact, live prey inside enclosures, and constant monitoring through GPS collars and cameras. Any jaguar showing signs of habituation to humans was excluded from release, because a predator that loses its fear of people will target livestock.

The gate opened on January 6, 2021. Mariua, then three years old, stepped out first, followed by her four-month-old cubs. She paused at the threshold, then disappeared into the reeds.

By the end of 2023, the wild jaguar population in Iberá had grown from three to 20. In 2022, one of Mariua’s cubs, by then an independent young adult, killed a six-foot yacaré caiman on its own. It was the first solo hunt recorded for that cub.

Researchers have compared the Iberá jaguar restoration to the return of wolves to Yellowstone National Park in the 1990s. The comparison points to a measurable mechanism: when an apex predator returns, it resets behavior throughout the ecosystem. The primary effect is not the number of kills but the presence of fear itself.

For nearly 70 years, capybaras grazed in open areas without disturbance. After jaguars returned, capybara behavior shifted within a single season. They moved more, spent less time in open areas near water, avoided locations where jaguars had been detected, and gathered in smaller, more dispersed groups near vegetation. A 2025 study documented this shift in real time. Fear alone was performing the ecological role expected of a predator, without frequent kills.

Where grazing pressure lightened, vegetation recovered. Grasses grew taller in areas that had been cropped to bare soil for decades. Transition zones between open water and dry land began to regenerate. Birds regained nesting cover, insects regained shelter, and seed dispersal resumed because animals began moving as their species had evolved to move.

The total cost of the jaguar reintroduction program, from initial planning in 2012 to the first wild releases in 2021, was about $9 million. The program produced 20 jaguars, a self-sustaining breeding population, and the beginning of a functioning food chain. Earlier attempts to control capybara overpopulation mechanically, through culling programs, fencing, and targeted removal, had recurring costs and produced no lasting vegetation recovery.

The program did not succeed without costs to local residents. About 1,800 landowners farm or raise cattle on properties bordering the national park. Jaguars do not recognize property boundaries. When one takes a calf from a neighboring ranch, it represents real income lost.

In 2022, a rancher in Colonia Carlos Pellegrini lost three calves over two months. He filed no official complaint with the park authority. He told neighbors simply that the jaguars had been brought back and local people were paying the price. The remark circulated through the community for months.

Rewilding Argentina responded with cattle vaccination programs and guidance on predator-resistant ranching practices. The organization is a non-governmental conservation group, not a government agency. It has no enforcement authority and no large-scale compensation fund to fully reimburse ranchers for losses. That tension remained unresolved.

A second challenge emerged in March 2024. A two-year-old female jaguar born in the wild in Iberá, part of the first generation born there in 70 years, was relocated to El Impenetrable National Park in Chaco Province, about 375 miles away. The goal was to establish a second genetically independent wild jaguar population in Argentina. She was named Akay.

She spent six months acclimating to the unfamiliar Chaco environment, a dry forest with a different prey base and terrain. She was released on October 5, 2024, wearing a GPS collar. After 20 days, the collar stopped transmitting. It was found in the Bermejo River. Investigators concluded she had been killed. Argentine authorities estimated environmental damages at over 2.6 billion pesos and offered a reward for information. Akay was one of the first wild-born jaguars transferred between national parks for conservation purposes in Argentina.

In early 2022, Corrientes Province experienced one of the worst wildfire seasons in its recorded history. More than 2.5 million acres burned across the province, and about 60 percent of Iberá National Park was affected by fire and drought. The jaguars were tracked through the event via GPS collars, and the population continued to grow. Births continued during the fire season. In 2022, a female named Iví 2, released separately from Mariua, gave birth in the open wetlands. These were the first jaguars born in the wild in Iberá in more than 70 years. They survived birth, nursing, and the fires that followed.

By 2025, the free-roaming jaguar population in Iberá reached 35 to 40 animals across three distinct generations. Scientists estimate the park could ultimately support about 90 individuals at full ecological capacity. Reaching that number depends largely on managing conflicts outside the park boundaries. Human tolerance has become the limiting factor, rather than habitat availability.

Jorge Uridó moved from cattle work to wildlife guiding in 2021, the same year the first jaguars were released. He saw no jaguars on his first eight guided trips. On the ninth, in March 2023, a female jaguar crossed the waterway about 40 meters from his boat. He cut the engine and watched her cross. He later said that in his youth, this landscape offered nothing worth bringing a visitor to see. He now takes tourists from six continents out at dawn to watch jaguars hunt.

Time magazine has named Iberá one of the greatest places to visit in the world. In 2025, the UN World Tourism Organization recognized Colonia Carlos Pellegrini as one of the best tourism villages in the world. The town, formerly dependent entirely on cattle, is building a growing part of its economy around the return of the animal it once helped eliminate. A living jaguar generates more sustainable economic value over its lifetime through tourism than a calf it might take from a nearby ranch. This does not erase the loss felt by a rancher who loses cattle. It means the overall economics of the wetlands have shifted for everyone living there.

The January 2021 release cost years of planning, roughly $9 million, failed breeding attempts, and the labor of scientists and rangers who worked without any guarantee of success. The results include 20 wild jaguars grown from three, wild births in open wetlands for the first time in seven decades, survival through fires and drought, and a small ranching town finding a new economic base. The results also include Akay, born wild in the wetlands, sent to help establish a second population, and killed within 20 days of entering her new home. Both outcomes are part of the same program.