Every December on the remote basaltic plateaus of southern Patagonia in Argentina, hooded grebes (Podiceps gallardoi) settle in to lay their eggs. Nearby, their personal guardians, field technicians charged with protecting the birds and their nests, stand watch. Armed with binoculars, flashlights, and shotguns, the guardians do whatever they can to eliminate threats to the grebes, although some perils are harder to see than others.

It is an extreme endeavor that requires both patience and warm clothing, says Ignacio “Kini” Roesler, a conservation biologist and ornithologist with Aves Argentinas, an environmental nonprofit in Buenos Ares, one of two main groups dedicated to protecting the hooded grebe. At up to 1,200 meters (3,900 feet) in elevation, the Patagonia steppe is a flat, open desert, dotted with more than a thousand glacial lakes, surrounded by rocky bluffs and framed by the Andes in the distance. The weather here is always harsh—windy and cold, even in the South American summer, when the hooded grebes build their nests on vegetation floating on the lakes.

The work of a colony guardian can be lonely. Other than a teammate or two for company, there is nobody around for hundreds of kilometers, and field stints in this harsh environment can last for weeks at a time. Despite the hardships, though, guardians are regularly reminded that their work is critical. “You are taking all this responsibility for the conservation of species,” Roesler says. “So, it’s pretty good actually—the feeling.”

With an estimated 800 to 1,200 hooded grebes remaining in the world, the species would be on the verge of extinction, conservationists say, if not for around-the-clock vigilance from colony guardians, among other rescue efforts. But such extreme actions also raise questions: Will conservationists be able and willing to maintain this vigil in the long-term? What will happen to hooded grebes if guardians stop showing up? And even with guardians in place, can the birds hang on in the face of such threats as climate change?

Protecting the hooded grebe is an exercise in hope that hints at the future of other endangered species, while testing the limits of how far people are willing to go in the name of conservation.

The birds spend their summer breeding season, from December through April, on the highland plateaus of Santa Cruz province in the southwest corner of Argentina. The area looks like a cross between the Sahara Desert and the alpine lakes region of Europe, says Mellone, who donned a dry suit and slipped into frigid lakes to get some of his photos. The lakes and their volcanic-ash beaches are so rarely explored that the first researchers who tried to survey hooded grebes had to make their own maps.

One of those researchers, ornithologist Jon Fjeldså, was already a grebe expert at Copenhagen University in Denmark when he heard about the discovery of the hooded grebe in 1978. Three years later, he traveled to Argentina to see the birds for himself. Teaming up with American ornithologist Gary Nuechterlein, who was there working on a separate study, the duo visited the grebe’s only known location at the time, a lake where they initially tallied 74 birds. Over the next two years—without GPS, maps, or much in the way of roads, and only satellite images to help him locate lakes—Fjeldså returned to look for more.

This time, he hit the jackpot. In one lake, he counted 700 grebes. After finishing the surveys, he estimated a population size of 3,000 to 5,000 hooded grebes. Looking back at the data, Roesler thinks the true number was closer to 10,000.

The hooded grebe has highly specific needs, Fjeldså observed, and the environment here seemed to meet them precisely. Lakes on the plateaus contained dense floating vegetation, the only places where the birds would build their nests. The lakes also varied in mineral composition, with some containing large amounts of silica or salt. And they were flush with snails, insects and crustaceans for the grebes to eat. The birds had little competition for food. That was key, Fjeldså says, because hooded grebes collect prey one at a time to feed to the single young they raise in a season. If parents can’t find enough food, they abandon their chicks, so breeding seasons can be hit or miss.

Although its precise requirements theoretically made the bird vulnerable, that didn’t seem to matter much at the time, Fjeldså says. Hooded grebes may live for a decade, so if they have one bad year, they can generally make up for it the next. His surveys suggested that the birds were doing fine, and the International Union for Conservation of Nature (IUCN) subsequently categorized the species as Near Threatened—not in need of special protections. “I felt at the time that, OK, it will manage quite well,” Fjeldså says.

For more than a decade after that, Roesler says, monitoring basically stopped and researchers left the species alone. “They said that the grebe is not in danger because it lives in such a remote place and there are not many chances for humans to mess around with the species,” he says, adding that a population of 5,000 individuals seemed like “a comfortable number for a bird.”

The team searched for an entire week before they found any grebes, Roesler says. In multiple lakes where Fieldjsa had counted hundreds of birds in the 1980s, they now found none. Over the course of a month, the team visited 186 lakes and found 535 grebes in 14 of them—an 80 percent decline in just 25 years. Five lakes accounted for 85 percent of the population. The results caused “complete panic,” says Roesler, who was about to begin a PhD project on Andean birds and decided then to study the hooded grebe instead. “We thought there were 3,000 or 5,000 birds up there, and suddenly there were nothing but a few hundred. It was a little bit terrifying because nobody knew what was going on.”

The grim tally on the plateaus hit Imberti hard, too, confirming what he had suspected while monitoring the wintering grounds in previous years: Hooded grebe numbers had plummeted when nobody was watching. “When you get the numbers and you get the fieldwork done… and you realize your hunch is real, it’s really, really depressing,” Imberti says. “But it was also urgent. So there was no time to dwell about that.”

Mink expert Laura Fasola, who was working on a study of competition between mink and Southern river otters at the time, remembers hearing about the slaughter with dismay. As early as 2005, she had noticed mink moving closer to grebe territory, and it had occurred to her that the predators’ range expansion could end badly for the birds. The news filled her with remorse. “My reaction was, ‘Oh my God,’” says Fasola, an ecologist with the National Scientific and Technical Research Council, an Argentinian government research agency. “I really regret not being more emphatic about what I found in 2005.”

In response to the latest news, she did her best to make up for lost time, documenting the extent—and the timing—of mink movements in the region. In surveys between 2012 and 2016, she and Roesler found that mink were periodic visitors to the high plateaus, arriving in mid- to late-summer and overlapping with breeding grebes for just a couple of months each year. Although relatively brief, that period was a particularly sensitive time when juvenile grebes, most of whom had already survived predatory bird attacks and wind storms, were preparing to set off on their own.

After that first documented surplus killing, two more followed over several seasons, adding up to 75 grebes killed by mink. In a paper that reported the discovery of mink in grebe habitat, Roesler, Imberti, and colleagues warned that the predators could be catastrophic for hooded grebes. But mink weren’t the only problem.

Kelp gulls (Larus dominicanus), a native species that preys on grebe eggs and chicks, is another growing threat. According to a 2011 study, the number of kelp-gull breeding pairs in northern Patagonia had increased by 37 percent over in the previous 15 years. Since then, the researchers have continued to see gulls in hooded-grebe habitat, and they have seen grebes behaving defensively when gulls are around.

Since 1940, a growing aquaculture industry has also stocked highland lakes with rainbow trout (Oncorhynchus mykiss), which have caused all sorts of problems for grebes. The fish compete with the birds for food; large trout prey on nesting grebes; and fishermen unintentionally trap grebes in their nets. In multiple studies, researchers have documented changes in the composition of microorganisms in lakes after exotic fish are introduced, with subsequent and sometimes drastic effects on waterbirds.

Climate change is a growing threat as well, causing lakes to disappear—something the scientists have observed first hand over decades of research on the plateaus. “A lot of the lakes that used to be really good for the grebes in the 80s, now were completely dry,” Roesler recalls from an expedition in 2011.

Such unconditional devotion to the hooded grebe appears to be working. Between 2011 and 2015, guardians helped protect 10 colonies for a total of 755 days, and their presence boosted the birds’ breeding success by 50 percent. In unprotected colonies, breeding pairs raised an average of 0.39 juveniles, compared to 0.64 juveniles per breeding pair in colonies that were guarded by grebe-sitters.

While the guardians keep watch, Fasola has been leading an effort to prevent new mink from replacing the ones that are killed by guardians. Since 2013, she and colleagues have placed more than 100 mink traps in lakes around the Buenos Aires Lake Plateau, one of the highest and largest plateaus in Santa Cruz province, and they continue to expand the work. Now covering about 5,000 square kilometers (1,930 square miles) and 550 kilometers (340 miles) of rivers, the area overlaps with both hooded grebe habitat and important mink corridors. It’s a huge area, but mink stick to rivers and streams, Roesler says, so focusing their trapping efforts in those waterbodies should help prevent new invasions.

The floating traps, which look like simple plywood birdhouses and kill mink on entry, attract the predators with meat slices and mink pheromones, which, Fasola says, her team acquires by collecting anal gland secretions on fur farms. They check the traps every five days—an effort that requires long, bumpy drives and walks of up to 25 kilometers (15 miles). The work continues until about early May, when the birds once again migrate to their wintering grounds. So far, the project has removed more than 120 mink, and there have been no documented mink attacks on grebes since the summer of 2016–2017, when a mink killed two adults.

Eventually, Fasola hopes to create a haven for mink that would provide optimal conditions for them. Along with management to keep population density low, the hope is that young mink would stay put instead of striking out into hooded grebe territories. Known as an ecological trap, the strategy has been implemented in Scotland, in an attempt to control invasive mink there, with mixed results. “We’re shooting to get to the point where we don’t need to keep the mink away from the grebe because they just won’t want to go there anymore,” Fasola says. “They’ll be in a happier place.”

Other conservation efforts underway include trout removal—which has increasing support from local fishermen—and work with fishermen to shift their winter activities to avoid grebes. Public outreach has taken a creative approach, such as a theater production for kids called “Quien se ha robado mi nido? Macanudo problemo!” or “Who has stolen my nest? What a problem!”—a type of interactive educational project that gets communities invested in the birds. Habitat preservation is another priority. In 2015, Argentina officially designated Patagonia National Park, a 52,000-hectare (130,500-acre) protected area that incorporates the hooded grebe’s primary breeding habitat, including the lake where Imberti and Roesler found all the dead grebes in 2011. Imberti named that lake “El Cervecero” (“The Beer Drinker”), in honor of his late father’s favorite soccer club.

With protections in place, hooded grebe populations have begun to level off, and annual counts suggest a slight increase, Roesler says. During the summer of 2018 and 2019, his team counted 782 adults across six plateaus, up from 764 adults the year before and 749 adults the year before that. Those counts cover an estimated 95 percent of the population.

What no one can say for sure is when, if ever, the work of the guardians will be done.

Still, many uncertainties remain. The budget for Asociación Ambiente Sur’s work on hooded grebes is $80,000 to $100,000 annually, Imberti says—a significant amount for conservation work in Argentina. “Without continued help, hope for grebes would lower quite a bit,” he says. Meanwhile, none of their threats have been eliminated.

Mink have been moving closer to two more plateaus where grebes breed, Fasola says. Climate change is continuing to bring less snow and more wind to the plateaus, accelerating evaporation. And two hydroelectric power stations are being planned for construction on the Santa Cruz River, the grebe’s prime wintering grounds. Those dams could be devastating, Roesler says, threatening not just hooded grebes, but also resident dolphins, cormorants, and penguins.

For now, the colony guardians plan to carry on. The hooded grebe has become an icon for Argentina, a symbol of wilderness, and a source of pride in a rare and beautiful creature that people can rally behind. Although its future is in peril, Roesler says, he knows what would happen if people didn’t keep fighting for the bird. “What you can say is that if you stop doing all these conservation efforts, the bird is going to disappear,” he says. “All the threats are happening right now.”