Once non-native livestock were removed and restoration began, native vegetation, wetlands and species like deer, rabbits and foxes returned.
When the sheep were removed, the páramo -- high-altitude ecosystems in the Andes -- started to heal. Without their waste, water quality improved. Without their hooves compacting the soil, plants began to grow again. Before long, shy white-tailed deer arrived, drawn by the grasses and shrubs for food and shelter. Not long after, pumas reappeared.
"This could serve as a case study for how food chains rebuild and slowly reshape the landscape," says Evelyn Araujo, a biologist with the Fundación Cóndor Andino (FCA), which monitors the páramos around Ecuador's Antisana volcano, southeast of Quito.
"It's also helping restore the region's ability to provide water to the city," says Silvia Benítez, director for the Latin America freshwater program at The Nature Conservancy (TNC).
In 2010, Quito's public water utility, Public Metropolitan Drinking Water and Sanitation Company of Quito (EPMAPS in Spanish), purchased approximately 7,000 hectares (about 17,300 acres) of páramo land from a former sheep ranch. Later, the Quito Water Conservation Fund (FONAG in Spanish) acquired additional land. Today, the Antisana Water Conservation Area (ACHA in Spanish), which lies in the western foothills of the volcano, next to Antisana National Park, covers 8,500 hectares (21,000 acres).
"We exist because of the quality and availability of water," says Bert De Bièvre, technical secretary at FONAG. "We are proud to fulfill that mission while also helping restore the natural balance of the ecosystem," he adds.
A history of sprawling haciendas
According to De Bièvre, in 1802, German geographer Alexander von Humboldt noted in his diary the heavy presence of cattle in the area during his visit to Quito. Over time, wetlands were drained and turned into dry sand flats. Benítez says that, for many biologists, Antisana became a cautionary example of how páramos should not be managed. After centuries of pressure, experts feared that much of the environmental damage was beyond repair.
Robert Hofstede, a moorland ecology expert and professor at the San Francisco University of Quito (USFQ in Spanish), notes that some properties between Antisana and Cotopaxi -- another active volcano to the southwest of Antisana -- once spanned more than 20,000 hectares (49,420 acres) and held thousands of livestock in critical water recharge areas.
Ranch workers set fires to convert the grasslands into pasture. Sheep and cows gathered in certain areas to rest and ruminate. "This, particularly in the Antisana, caused the most severe degradation," says Hofstede.
Benítez explains that the animals' weight, population density and hoof shape compacted the soil, making it hard and reducing its ability to retain water. With little vegetation to hold it down, the wind triggered sandstorms.
The herds drove out white-tailed deer (Odocoileus virginianus), Andean tapeti (Sylvilagus andinus) and Andean foxes (Lycalopex culpaeus), while ranch workers ensured that pumas (Puma concolor) stayed away. Outside the ranch boundaries, ranchers also hunted deer, Hofstede says.
A race against the clock
Hofstede recalls that the Páramos Project, in which he participated, along with debates in Ecuador's former government over environmental protection laws, and efforts by various institutions, helped spark a mentality shift in the late 1990s and early 2000s.
Former hunters noticed native wildlife becoming rare and began to put down their guns. On some ranches, cattle were gradually removed from the highlands. Younger generations turned to tourism, converting parts of their land into places for horseback riding and hiking.
"The one who resisted everything was Delgado," Hofstede says. Delgado was the owner of the large ranch located at the entrance to what was then the Antisana Ecological Reserve -- an area that would later become Antisana National Park in 2021. To enter the reserve, visitors had to obtain several permits from him. "At the time, it was still the ugly duckling of Ecuador's National System of Protected Areas."
Water users finance conservation
FONAG is "an alliance of major water users in Quito's Metropolitan District," De Bièvre says. It was founded in 2000 by EPMAPS and TNC, with other private companies that are significant users of water. Each institution contributes to an 80-year trust fund, established with the goal of conserving and protecting the water supply for Ecuador's capital city.
The fund's primary source of income is 2% of the revenue collected by EPMAPS from its customers -- meaning the people of Quito are its main contributors. De Bièvre notes that the fund also has other sources of income. One example is a water footprint offset program, in which major companies like General Motors and Quiport, the company that operates the city's airport, contribute to the fund.
"I believe it is one of the most sustainable and reliable environmental financing mechanisms out there," De Bièvre says.
The fund's capital is used to protect and restore nine key water source areas for Quito, including four designated water conservation zones covering roughly 20,000 hectares (49,420 acres).
Clearing the sheep and restoring the páramo
Ten years after FONAG was created, the fund had enough capital to purchase the Antisana ranch and begin a restoration effort once thought impossible. When the former owners removed the livestock, there were "relatively quick improvements in water quality," De Bièvre says: Waste from the animals had been polluting the water sources.
Over time, he says, they realized that some stray cows and sheep had remained in the area -- mostly in hard-to-reach places -- and their populations were starting to grow again. The biggest issue, however, was horses. For decades, ranchers had released horses that were no longer fit for work, allowing them to breed and turn feral.
"We realized we had to take more drastic action," De Bièvre says. Working with local communities, they were able to control the presence of non-native animals. According to Benítez, the role of park rangers was crucial. They were responsible for keeping livestock out of the páramo and also helped prevent the spread of wildfires.
One of the toughest challenges was restoring wetlands that had been drained for decades. Hofstede explains that technical teams working in the ACHA began closing old canals using small dams. As a result, the phreatic level -- the natural water table -- began to rise.
"It was one of the first examples of wetland restoration," Benítez says. Restoring these areas brought back the páramo's key function of retaining water.
The former sand flats were also a major concern: Wind erosion had deepened over time, leading to sandstorms. FONAG teams installed physical barriers to stabilize and protect the soil.
Little by little, the bare sand and grasses gave way to native vegetation. This recovery was supported by planting straw grasses, shrubs and other local species.
Equilibrium returns
Benítez says that once the native plants returned, so did insects and macroinvertebrates -- species that signal the health of freshwater ecosystems. Rabbits also came back. These animals, in turn, attracted predators like Andean foxes, black-chested buzzard-eagles (Geranoaetus melanoleucus) and carunculated caracaras (Phalcoboenus carunculatus).
The white-tailed deer population rebounded so quickly that it raised concerns among FONAG's technicians. "We started to wonder if maybe it was too much," De Bièvre says.
In 2021, FCA began monitoring the Antisana páramos with camera traps, since the area is home to 33% of Ecuador's Andean condor (Vultur gryphus) population, Araujo says.
In the first year of monitoring, the foundation's team found that condors, which had long fed on cattle carcasses in the páramo, were once again feeding on deer carrion -- a promising sign.
However, some deer showed signs of being killed by dogs, Araujo notes. Camera traps confirmed this, capturing multiple instances of dogs in various areas. In contrast, the puma, the top predator in this ecosystem, was recorded only twice that year.
But things began to shift in 2022. Dog sightings decreased, while puma sightings increased, Araujo says. One image even showed a puma mother with two young cubs. That's a strong indication, the biologist says, that the habitat is now rich enough in resources to support breeding and the survival of offspring.
The pumas have helped keep the dog population in check, and now, during their patrols, the FCA team finds deer carcasses showing clear signs of having been hunted by the big cats.
One of the most exciting findings, according to Araujo, was the presence of an Andean bear (Tremarctos ornatus). He explains that this species passes down knowledge of trails from one generation to the next. Because the Antisana area had been occupied by non-native animals for so many decades, the bears had avoided it. But now, he says, "perhaps intuition or curiosity" led this one to explore the territory once again.
Leading by example
According to Benítez, FONAG has become a "benchmark" for environmental conservation. This is due to several key factors. First, he explains, "it's a simple concept to understand -- those who use the water commit resources to protect the ecosystem that provides it."
Second, he continues, it proves that collective action among public agencies, private companies and NGOs can be effective. And finally, it's a model that can be shared: Experts and representatives from water utilities in Guatemala and Colombia have visited FONAG's protected areas to learn from its approach.
"For me it's a story of hope," says Benítez. "We now have more than 26 water funds in Latin America and over 50 worldwide," he adds.
Hofstede emphasizes that nearby communities have also embraced conservation and now serve as the first line of defense. "They're the ones who report when people come in on enduro motorcycles. They're the ones who keep watch and alert us to wildlife sightings," he says.
"It gives us hope -- restoration is possible," reflects De Bièvre. For Araujo, Antisana is a "living laboratory" that demonstrates how "even completely degraded areas, with careful management, can become success stories in restoring water sources and the food chains that rely on them."
Banner photo: A puma spotted in 2022 in the Antisana páramos. Image courtesy of Fundación Cóndor Andino.
This article was first published here in Spanish on Mar. 19, 2025.