THE FROG WAS UGLY CUTE. Its wrinkled neck bulged over a shield-shaped head, small eyes squinting at me through a shimmer of water. I surfaced in a gasping excitement, spitting out my snorkel, my flippers sending storms whirling through the bottlebrush algae of the lake.

“I see a frog!”

“Good,” Jaime Salamanca responded encouragingly.

In the thin bright air surrounding Lake Titicaca, 12,500 feet above sea level, he explained how we were going to count them.

The Titicaca water frog is physiologically bizarre, critically endangered, and one of the most important predators in the unique altiplano lake that spans more than two million acres between Peru and Bolivia. It has also captured the attention of a handful of hardscrabble Bolivian biologists and conservationists: Arturo Muñoz, Jaime Salamanca, and Gabriel Callapa. Earlier this year, my husband, two children, and I spent three weeks snorkeling the lake under their direction, collecting data on this unusual amphibian.

We first met the scrappy research team 200 miles from the lake in Cochabamba, a balmy, bustling city in central Bolivia. In a small corner of space carved out from the back rooms of a natural history museum, Salamanca, Callapa, and I spent a rushed couple of hours under the glass eyes of stuffed birds, peering at spreadsheets full of years of frog data and drawing up plans on a map of Lake Titicaca. Muñoz joined us on a Skype video call that cut in and out unpredictably, leaving us staring at his Kermit the Frog icon every time the connection was lost. The founder and heart of the Bolivian Amphibian Initiative, he was finishing his PhD in Belgium, bouncing back and forth between Bolivian field seasons and European thesis work.

As a boy in Sucre, Bolivia, Muñoz was scared of frogs. He often found himself fishing them out of his parents’ swimming pool with a very long stick and wanted nothing more to do with them until years later when, as a biology student, a friend who kept frogs as a hobby began dragging him out to go look for them in the Amazon rainforest. On his first trip, he got lost with a group of students in the dark jungle — they ended up burning their clothes for a bit of light to find their way out. Surprisingly, he went back for more. They photographed species they couldn’t name, and puzzled over a black and white photocopy of a guide Muñoz couldn’t read.

While this friend taught Muñoz, now 40, to love frogs, it was a workshop in Europe that taught him to save them. In 2006, he attended a course put on by the Durrell Wildlife Conservation Trust. “Before that,” he says, “I didn’t really understand what conservation was.” The workshop launched him into the field. “No one was working in amphibian conservation in Bolivia. I was going to start by myself.”

With his newfound connection to the global conservation community, Muñoz didn’t feel alone. He began working with students, and seeking out $500 grants to cover bus tickets between Cochabamba and the lake. “Don’t find excuses that you cannot do something now because you do not have the resources,” he says.

Of all the world’s animals, amphibians are perhaps the most in need of champions. Since the 1970s, around 200 frog species have gone extinct, and globally, around 40 percent of amphibian species are at risk of extinction. Latin America can claim both the greatest amphibian diversity and the steepest amphibian declines. Bolivia alone has an estimated 270-plus frog species. In other words, there are plenty of frogs in need of Muñoz’s help. Ultimately, the frogs Muñoz chose to begin with weren’t those of his subtropical home, or the colorful creatures of the Amazon jungle, but the water dwelling beasts of South America’s cold, high Altiplano.

Why these frogs? Most of Bolivia’s frogs are nocturnal things with bulging eyes that spend their waking hours leaping between vines in the Amazon jungle. But the Titicaca water frog, or Telmatobius culeus, is a creature apart. It never leaps, never leaves the lake to which it is endemic, and in fact, never even surfaces. It survives at an altitude that leaves visitors gasping, without ever taking a breath. The frog has great folds of skin that flap out from all sides, as though it were wearing a sweatsuit a good dozen sizes too big. All that surface area lets it absorb what little oxygen dissolves into the chilly waters of the lake. The folds and wrinkles have earned it the nickname “scrotum frog.”

With a name like that and an appearance that netted it fourth place in the British Science Association’s ugliest animal contest in 2013, this strange water frog could be considered the charismatic “megafauna” of Bolivian amphibians. But it was neither its uniqueness nor its name recognition that convinced Muñoz to take on its cause in 2008. For him, the choice was a matter of triage. “I realized that these aquatic frogs Telmatobius were having more problems [than other amphibians],” he says. “I focused on this group because no one was working with them. I decided to focus on a species in a crisis situation.”

STRETCHING THROUGH the Andes Mountains of both Bolivia and Peru, Lake Titicaca is the world’s highest navigable body of water and the largest lake in South America. The Incas claimed the lake as a birthplace, and ruins surrounding it are thousands of years old. Unique in the cold dry lands of the Altiplano, the lake was designated as an internationally significant wetland site under the Ramsar Convention in 1998. Flamingos stride through reedy shores and gulls wheel overhead, while coots and teals paddle the water’s surface. Hundreds of species call the lake home, and many of them, from tiny snails to the flightless Titicaca grebe, live nowhere else in the world. The Titicaca water frog is one of these endemic species.

The Titicaca water frogs were made famous in 1968 when legendary explorer and filmmaker Jacques Cousteau took his divers and submarines on a long train ride over the Andes to search the bottom of the lake for lost Inca cities of gold. In the gloomy depths 400 feet below the surface, frog feet left tracks in the mud. Frogs sat on underwater rocks, swam through totora reeds, and in a lake short on both fish and gold, became the unwitting stars of Cousteau’s documentary about the adventure. Near the end of the film, he had his divers swim through an acre-sized section of the lake, filling plastic bags with all the frogs they could find. As one of the divers spilled a tub of just-counted frogs back into the lake off a cliff edge, Cousteau announced his back-of-the-envelope math in a breathless voiceover — he estimated the lake held more than one billion of the frogs.

By the time I put on my snorkel mask 50 years later for an updated population count, the Titicaca water frog was listed as critically endangered on the International Union for Conservation of Nature’s Red List. There’s no reliable population count for the species, but it’s believed that their numbers plummeted some 80 percent between 1990 and 2004, when they were added to the list. Given the number of obstacles the frogs face, including everything from predation to water pollution, these losses aren’t entirely surprising.

Over the past few decades, the frogs have been struck by a series of mass die-offs. In April 2015, thousands washed up dead in Bolivia. In October of 2016, 10,000 more washed up in Peru. There were die-offs in 2009, 2011, and 2013 as well. The periodic waves of dead frogs found on Lake Titicaca’s shores can most likely be attributed to pollutants that trickle into the lake from nearby cities that lack adequate water treatment facilities and from farmlands when it rains. The 2015 Bolivian die-off, for example, began with nutrient-loaded runoff, which led to an oxygen-sucking algae bloom. From there, winds and rains that released hydrogen sulfide from the lake bed were enough to starve the frogs of oxygen, killing 80 percent of those in the shallow arm of the lake. Pollution from the mines that dot nearby hillsides probably doesn’t help either — lake fish have been found with elevated levels of mercury, cadmium, copper, and zinc.

Then there are the pressures related to the local fishing industry and nonnative species. A half-million rainbow trout eggs from Michigan were dropped from airplanes into Lake Titicaca in the 1940s, and trout have thrived in the high-elevation waters ever since. Over the past few decades, the Titicaca water frog has been struck by a series of mass die-offs. Kingfish, introduced from Argentina a bit later, now make their home there as well. These nonnative fish now form a cornerstone of the regional economy, but are known to prey on the dozens of species of killifish endemic to the lake, at least two of which are now believed to be extinct. Muñoz believes the trout eat tadpoles too, and is undertaking research to determine just how big an impact predation is having. The fishing industry has taken its toll in other ways as well — the frogs get snagged in nets meant for fish, and the trout-raising pens that dot the edge of the lake might affect frog breeding habitat, though more research is needed on this, too.

The fish-related issues could prove challenging to address. “We’re trying to solve the problem of pollution,” Muñoz said, referencing a government plan to build water treatment plants in surrounding cities. “But the trout and kingfish — the government has supported those. It will be almost impossible to change that.”

Over-harvesting may also be playing a role in the frogs’ decline. Tourist restaurants along the Bolivian coast offer meals of frog legs, while some locals believe the frogs have medicinal properties. Some evidence suggests they are being sold for consumption in cities in Peru and Bolivia, though the extent of the trade is unclear.

Finally, there’s the looming threat of Batrachochytrium dendrobatidis, more commonly known as chytrid fungus. Amphibians are fragile, absorbing everything they touch through their skins. A frog cupped in your hand might be poisoned by your sunblock or bug spray. A frog in the creek might be poisoned by pesticides or metals. This exquisitely sensitive skin has also made frogs especially susceptible to an outbreak of the deadly chytrid fungus.

Originating in Korea in the 1950s, chytrid has spread to almost every corner of the globe via human activity. Sometimes called the most devastating plague in wildlife history, chytrid causes the skin of infected amphibians to thicken, stiffen, and slough off. It leaves some frogs unable to absorb water and electrolytes through their skin — as a result, their heart stops. In others, the skin thickening renders the amphibians unable to breathe, leading to suffocation. Chytrid fungus alone has driven more than 200 species of amphibians to extinction or near it, but hundreds more are susceptible. The fungus has been found in Titicaca water frogs, but they have yet to succumb to the disease in large numbers. The cold temperatures and high pH of Lake Titicaca may provide a check on fungal growth. Or perhaps larger die-offs are yet to come.

FOLLOWING A SNORKEL TEAM along the shores of Isla de la Luna, an island in the lake’s southeastern stretches, I didn’t have time to ponder the broader fate of the Titicaca water frog. I was worried enough just trying to keep track of the frogs we were surveying that day. Each time Salamanca popped up with his snorkel mask still on, he had another five or ten frogs to report, a mass of data I could hardly scribble fast enough. Hours passed as we crept along the shoreline. The grassy hills of the Altiplano morphed from washed out gold to sunset orange. Finally, my husband and Salamanca crawled shivering out of the 50-degree-Fahrenheit water, a few hundred meters shy of the village that was the end point of our study transect.

Isla de la Luna is the smaller, less-famous cousin of the Lake Titicaca tourist mecca that is Isla del Sol. Less than two miles long and a third of a mile wide, a few dozen buildings cling to a hillside terraced in beans and potatoes. Llamas and cats wander between concrete homes filled primarily with the old and the young — most of the young adults have moved elsewhere for work. Cell phones, ubiquitous here, are charged by just a few solar panels. On the other side of the island, boats roar in with tourists, headed for the ancient Inca temple of the virgins. Someday, Muñoz and Salamanca hope, the frogs might be as much of an attraction as the ruins.

The frogs, Señora Esperanza believes, are protectors of the ispi, a type of killifish. A quiet Aymara woman with long black braids and a smile that crinkles her cheeks, Esperanza and her husband Don Porfidio were our hosts for the time we spent on the island. In rotation with the other dozen or so families in the village, they take turns housing and feeding the handful of overnight tourists while tending scattered fields of potatoes and beans, catching ispi, and farming trout. Ispi are nocturnal, and each night, around 2 a.m., the family launches its tiny skiff to pull up fine mesh nets of the anchovy-sized fish. We ate them everyday for lunch, fried crispy and whole in an oily pile next to potatoes and beans.

In 1968, when Cousteau made his trip to Titicaca, there was “nowhere without frogs.” Cousteau didn’t think it mattered in which part of the lake he counted them. Today, the folks at the Bolivian Amphibian Initiative know better. They’ve established around 20 research tracts, each around half a mile long, on the southeastern end of lake, surveying frogs across seasons and years. They conduct regular counts at each site, and had trained us how to spot and count the frogs as well.

Snorkeling for frogs is a little like looking for your keys under a lamppost. Weaving along steep cliffs and knee-deep shallows, through sparkling clarity and fogs of mud, you choose a line where you can see, and hope for the best. With every frog, or every ten meters without one, you pop your head up, tread water, and shout details to the data recorder traveling alongside you on land or in a boat: water depth, frog size, number of centimeters from the survey line, what it is sitting on, and the habitat surrounding it. The data comes in spurts of rapid-fire Spanglish: “Seven point six, grande (big), distancia diez (distance of ten), on a roca (rock), roca, planta, arena (rock, plant, sand)!” Where frogs were common, I struggled to remember half a dozen sets of details at a time, while my husband struggled to write them quickly enough. Where frogs were rare, chills and boredom set in as we slowly scanned the sweep of barren sand.

Every tract is different. Some of the most polluted research sites — typically near past frog die-offs — have no frogs at all. The shallows near Isla de la Luna, on the other hand, are crowded with them. On Bolivia’s more remote northeastern shore, no one had ever counted frogs before the BAI team sent us there in 2018. They had hoped to find strongholds of the species in this more remote and less polluted area. Fortunately, the frogs were there.

Frog size can vary widely from site to site. In the waters around Isla de la Luna, for example, I could have cupped most of the frogs in my gloved palm. Their bodies measured around 3 inches by 2.5 inches, not counting the legs. Around the desolate Isla de Campanario, our destination on day nine, they were bigger than my fist, sometimes bigger than my breakfast bowl. One peering up at me from deep in the algae, where I almost mistook it for a rock, was the size of a dinner plate.

Back in Salamanca’s Cochabamba apartment after three weeks in the field, it was time to start digging into the data we had collected. Each frog popped up as a circle on the map — little ones and big ones, some the lonely kings of their stretch of coast, others nearly overlapping in their abundance, each one a point of hope for its species. Near die-off areas, the frogs seem to be smaller — Muñoz speculates that perhaps they are younger, moving back to recolonize habitat.

Despite the major inroads the researchers have made when it comes to understanding these mysterious frogs, there’s still so much to learn. Currently, no one really knows exactly how many of the frogs there are. Or how they breed. Or how long they live. Which is why, in addition to working on a population count, the Bolivian Amphibian Initiative team is scuba diving to gather information on frog reproduction, behavior, and habitat preferences; gathering water samples to test for things like quality and UV radiation levels; and documenting die-offs. With limited funds and so many environmental factors beyond their control, they hope more information will help them target their efforts and focus on saving the frogs where populations are still healthy.

WHAT MUÑOZ AND HIS TEAM are trying to accomplish with the Titicaca water frog and other Bolivian amphibians is more than a little daunting. With an average per capita yearly income of barely more than $7,000, Bolivia is the poorest country in South America. People here are struggling to make ends meet, and the government is struggling to help them. Conservation doesn’t always rank high on the agenda, and success isn’t as simple as establishing protected areas.

“National Parks don’t work here,” Muñoz says. The parks that do exist offer few protections, he explains, often allowing activities like logging and mining. Formally adopted recovery plans, government funded initiatives, areas protected in more than name only — none of that will happen in Bolivia, at least not in the near future.

The last time I spoke with Muñoz, before I left Bolivia, he was dispirited. Without government funding, he has had to get creative, and over the years he has turned to other organizations for support. A recent clash over logos and attribution had led to a break with the Bolivian museum that had been providing space for his program. This meant a loss of most of the Bolivian Amphibian Initiative’s equipment, their office space, and their entire captive breeding program for the frog, which was a central component of the initiative’s conservation strategy.

Muñoz was also becoming increasingly troubled with the fates of lesser-known species, frogs that may be even more threatened than the Titicaca water frog. This has put him at odds with other collaborators. “They [the NGOs] told me if you take this [Titicaca water frog] out of the grants, there will be less money,” he says. “It is much easier to get money to work with the Titicaca water frog because it is more charismatic. Like a panda.”

On top of all the stress and heartache, Muñoz is doing most of his research for free. Salamanca and Callapa are too, something he feels especially bad about. But as Muñoz notes, money often comes with strings attached, and he’s unwilling to compromise his research ethics or conservation philosophy. “I have not been paid in almost one year,” he says.

As might be expected, his family life has suffered. He considered quitting. But even his small son pleaded with him to keep at it: “You can’t stop working with frogs,” he told his dad. “You have to keep working with frogs!”

And so far, the Bolivian Amphibian Initiative has kept at it. In 2017, they piloted an ecotourism project on Isla de la Luna, assessing the potential for the program to draw frog-loving snorkelers. Salamanca and his wife lived on the remote island for six months, guiding snorkeling tourists, while the local community earned income by providing lodging, food, and transport. “I had this idea in mind that people can’t care about what they don’t know,” Salamanca says. “They have to go outside, feel the nature, smell the nature, touch the nature.”

With a little advertising in the tourist mecca of Copacabana, he feels they could easily attract far more tourists than the handful they brought in. They just have to secure more wetsuits, which is hard in Bolivia, where there’s nowhere to purchase them.

The initiative is also working with the Isla de la Luna community to establish a frog sanctuary around the island. They are currently trying to figure out which areas are most important to the frogs, and how local activities can be modified to protect it.

Despite the setback with the natural history museum in Cochabamba, Muñoz continues to explore captive breeding options for the frog, which has successfully been bred in cities in both Peru and Bolivia, but has yet to be bred locally near its native habitat. Additionally, Muñoz and his team have led research courses for budding biologists in Bolivia, Peru, and Argentina; trained local community members so that they can contribute to amphibian research and frog monitoring efforts; and developed educational materials on local amphibians for the broader public.

In 2017, their work got a boost when the Titicaca water frog was listed under Appendix I of Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the international treaty that regulates the global wildlife trade, essentially banning international sale of the frogs. That same year, Peru and Bolivia committed $500 million to cleaning up Lake Titicaca.

Muñoz and the rest of the BAI team are idealists — it seems unlikely that he’ll stay dispirited for long. He and his colleagues envision a future in which the people of Isla de la Luna move their trout pens, fishing nets, and boat traffic away from the frogs’ most important habitat areas in the lake, and snorkeling tourists provide a meaningful source of income for locals. A future where captive breeding programs keep a population of frogs safe in case of disaster, and water treatment plants stop the flow of pollutants into the lake. A future where they don’t have to fight tooth and nail for government support, and don’t have to work for free. Where they can champion the cause of not only the Titicaca water frog, but of all the amphibians that need their help.

In the meantime, they are keeping their noses to the grindstone and getting things done. Salamanca plans to put his tourism skills to use, earning money for conservation with no strings attached. Callapa thinks he can make a living through other endeavors, and work with frogs on the side. Muñoz plans to earn whatever he needs to survive in Belgium. While in Bolivia, you can expect to find him somewhere in the countryside, camping with his wife and two small children, and whichever frogs need him the most.