- An intensive search is underway in Laos to find perhaps the most threatened large mammal on the planet: the saola ox.
- Sniffer dogs, local and international wildlife tracking experts, and a state-of-the-art DNA kit have all been deployed to try to home in on any unknown individuals of the species so elusive conservationists once dubbed it the “Asian unicorn.”
- Last documented in 2013, when a camera trap photographed an adult in central Vietnam, previous attempts to study the saola have been stymied by a lack of sightings.
- Conservationists are aware of the ever-ticking clock, however, and warn that extinction is “inevitable” without a dedicated and intensive push to study remaining individuals and safely bring them into captivity to start a conservation breeding program to revive the species.
Few people have the opportunity to meet near-mythical beasts in real life — but Rob Timmins has. He’s one of the few biologists ever to spend time with a saola, a wild ox once known as the “Asian unicorn,” and arguably the most threatened large mammal on the planet.
First described by science in 1993, the species, Pseudoryx nghetinhensis, has only ever been recorded alive a handful of times: five camera-trap detections, and a few individuals briefly held in captivity.
Timmins met one of those captive animals, a female named Martha, in 1996 after she was captured by villagers in Laos and taken to a nearby facility. She survived there only a few weeks before passing away.
Martha was “truly beautiful amidst all the sadness of her captivity,” says Timmins, who is now chief technical adviser of the Saola Foundation for Annamite Mountain Conservation. “In behavior, [she] was very unlike any other ungulate I’d ever seen. Very docile, seemingly very calm.”
The saola’s peaceful nature has in fact earned it a nickname in a Lao dialect: Saat Supphap, which means “polite animal.”
The species is considered so evolutionarily distinct it’s placed in a genus of its own. Sporting a hefty pair of dark horns, a sloping back and bold flashes of white across the face, saolas resemble antelopes, yet their closest living relatives are wild cattle like gaur and buffalo.
Yet the world is on the cusp of losing this gentle, one-of-a-kind mammal forever, before scientists have even begun to unravel its mysteries.
There have been multiple efforts to locate saolas in their range in the Annamite Mountains, which straddle Laos, Vietnam and northeast Cambodia — although saolas have never been recorded in the latter country. The last confirmed sighting in the wild was a 2013 camera-trap image from Central Vietnam.
With so few records, experts agree saolas are likely in deep trouble. A 2021 report by the Saola Working Group at the IUCN, the global wildlife conservation authority, analyzed all known data on the species and concluded there are likely still some individuals hiding out in remote forests, dotted across vast landscapes and in “extremely low numbers.” The report recommended urgent and intensified search efforts to study the species before it’s too late.
An all-out search
Timmins says the poignancy of his encounter with Martha only grows with time as the plight of the saola deepens.
Resolved to act to save the species, Timmins and his colleagues at the Saola Foundation are now going all out to find any remaining saolas in central Laos. They’re deploying a highly trained team of sniffer dogs, local and international wildlife tracking experts, and a state-of-the-art DNA kit.
With several months of training and preparation behind them, the team ramped up the search to full strength in April 2025. They’re aiming to complete 24 months of searching across 300 square kilometers (116 square miles) of remote and mostly unprotected prime saola habitat — an area about a fifth the size of Bangkok — in central Laos’s Bolikhamxay province.
“What we’re dealing with is a low-density population — individual animals scattered around in unknown locations,” says Lorraine Scotson, CEO of the foundation leading the search.
The numbers are likely so low that basic ecological processes are hampered. “The population is very likely made up of isolated individuals [that are unable to] find each other to breed,” Timmins says. He calculates no more than 50 saolas likely remain across the entire Annamite region, possibly living at a density as low as 1 saola per 100 km2, or about 2.6 per 100 mi2.
The species was driven to this desperate state by a deadly combination of habitat loss and intensive snaring that began in the 1990s. Burgeoning markets for wild meat and wildlife-based traditional medicines have resulted in millions of wire snares littering the saola’s sole habitat. As wide-ranging forest browsers, they’re thought to be particularly vulnerable to stepping on snares.
Even if the threat of snaring were completely removed, Timmins says the species is likely caught in an extinction spiral due to its small population size. “I think that few would disagree that extinction in the next decade will be inevitable (unless intervention is successful),” he says.
Scotson describes the situation as a ticking clock. “Even if there are individual saola out there, every day that goes by, those saola are getting older and ultimately beyond breeding age,” she says. “So regardless of how many there may or may not be, the urgency of finding them is building.”
To catch a unicorn
With the outlook for saolas so dire, conservationists and the species’ range countries — Laos and Vietnam — decided in 2017 that the best way to rescue the species would be to capture any remaining individuals to start a conservation breeding program, with the end goal of eventually returning the captive-bred animals to the wild once safe, snare-free habitats are available.
Given that there are no saolas currently in captivity, the Saola Foundation’s search to locate wild individuals is a key first step in this long-term vision. Capturing ungulates can be a risky process, though, not least due to their tendency to go into physiological shock that can prove fatal.
Scotson says she’s positive that any future captures can be done safely, however, by following the best veterinary guidelines available and by learning as much about saola needs and behavior beforehand.
This is why if they do manage to find saolas, the team intends to study the animals in the wild before rushing in to make captures. Right now, despite attempts to study the species using camera traps, village interviews, and even leech blood, almost nothing is known about their foraging ecology, their behavior, or their daily movements.
To further mitigate risks, the team is developing safe capture methods by working with local researchers who are studying a similar species: the large-antlered muntjac (Muntiacus vuquangensis). The focus of similar efforts to establish a captive-bred insurance population, the muntjac is more common than the saola, but also perilously close to extinction, endemic only to the Annamites, and facing the same slew of threats.
Led by researcher Nguyễn Thị Ánh Minh, the muntjac team is testing the effectiveness of various methods, such as bait, capture methods and enclosure designs, that will help the saola team design a safe strategy for any saolas found in the wild, Scotson says.
Dogs, DNA and dung
To find and study any remaining saolas in the wild, the team have developed meticulous tracking techniques that go beyond traditional methods like camera traps, which are more useful for confirming presence or absence. As Scotson puts it: “It’s like a missing person search on Mount Everest.”
Onkeo Khamphavongsa, one of the trackers, says he’s learned to envisage the forest in which he’s always lived in a completely new way since he joined the initiative and received training from experts at CyberTracker, the developer of widely used wildlife monitoring software.
“When I’m in the forest, I now see all the evidence of animals: the scat, the footprints, the evidence of feeding,” he tells Mongabay via an interpreter. “It’s like learning to translate the language of the animals.”
For the first time ever in Laos, sniffer dogs — two spaniels named Normal and Bertie — are a key part of the effort. With no well-preserved saola scat in existence, the dogs were trained to detect the dung of all ungulates, maximizing the chances of detecting evidence of saola if they encounter it.
Pete Coppolillo, executive director of Working Dogs for Conservation, a U.S.-based nonprofit partnering with the Saola Foundation, says dogs are uniquely adapted to search for elusive targets that exist at low density and in complex habitats, like the saola. “They can learn new scents almost immediately and collaborate with humans in finding it,” he says. Sniffing out signs of other ungulates is worthwhile, given “many of them are important species for conservation as well,” he adds.
Working Dogs for Conservation notched up a recent breakthrough in the search for another elusive and critically endangered large mammal: its dogs managed to detect suspected Sumatran rhino dung in a national park in Indonesia. The species, Dicerorhinus sumatrensis, was thought to have disappeared from southern Sumatra, after years of ranger patrols, camera trapping and drone monitoring failed to find any trace of the animals.
Another major breakthrough for the saola team is its collaboration with the Wildlife Conservation Society’s Wildlife Diagnostics Lab at Bronx Zoo in the U.S. The lab is providing the team with portable, rapid DNA field testing kits specifically developed to confirm within just two hours whether dung samples, fur or chewed leaves come from a saola.
The WCS lab had already developed a similar portable test based on quantitative polymerase chain reaction technology, or qPCR, for a rare turtle in Vietnam. However, developing a DNA kit for a species with no known living individuals presented unique challenges, says Tracie Seimon, director of the laboratory at WCS, who was involved in developing and validating the kit.
“We had to be a bit creative,” Seimon says, noting it took more than a year to develop, and involved creating “mock” saola dung by inserting scraps of saola DNA from the remains of archive samples into antelope feces.
The technology is “an absolute game changer” for tracking saolas, Scotson says. “Without the kit, the delay while we waited for lab results would have meant any saola confirmed by DNA could be long gone and impossible to track,” she notes.
Conservation gains, whatever the outcome for saolas
Several months into their intensive search, the team has yet to uncover any evidence of saolas. Timmins says he isn’t disheartened, however. Detection was always going to take time, and he remains convinced some individuals are still hiding in remote areas, he says: “There’s vast areas of forest in which detection of exceptionally low-density species [is] difficult. It’s more likely than not small numbers of saola still survive.”
Whether they find saolas or not, the efforts of the search will not have been in vain, Timmins adds. The foundation employs and has trained dozens of Lao citizens, 11 of whom are from rural Annamite communities, giving a much-needed boost to the region’s conservation capacity, he says.
The tracking team has already gathered important new data on several other at-risk species that currently get limited conservation attention, he adds. Besides the saola, the Annamite Mountains are home to a host of rare and endemic fauna and flora, many of which have only recently been described by science.
Now, the tracking team might be on the brink of adding to that list. While surveying a remote limestone karst outcrop in 2024, they observed a group of leaf monkeys with strikingly shorter and stubbier tails than any other monkeys known from the area. The team suspects they might be a new, undescribed species, and is working to gather the evidence needed to confirm this theory.
Besides tracking and monitoring wildlife, the team also reports threats like snares and illegal logging to authorities, and speaks to villagers living in remote and unprotected forests about preserving local species rather than hunting them. As such, its members are serving as vital “conservation ambassadors” in forest communities that are often difficult to reach, according to Scotson.
Toward a safe forest to rewild
Building local awareness of saolas and their plight will be critical to the success of a potential conservation breeding program in the future. There would need to be safe and well-protected forests for any captive-bred saolas to return to.
Achieving snare-free forests, however, will be a “long and difficult task,” according to Andrew Tilker, species conservation manager at Re:wild in Vietnam, who isn’t involved in the Saola Foundation’s search. “It may take many years of effort before we have protected areas in the Annamites that are safe enough for large-scale reintroductions,” Tilker says. “It’s important that conservation stakeholders start working towards this as soon as possible.”
Ranger-led snare-removal patrols are widely deployed in the region as a stop-gap solution to the crisis, but they require immense funding and labor resources, limiting their sustainability. Solutions have to be holistic, Tilker says, encompassing stronger protected-area management and wildlife laws; encouraging poachers to stop snaring; and reducing demand for wildlife products, particularly among urban populations.
In the meantime, the search for any saolas tucked away in unexplored parts of Laos will continue. Scotson says hopes are high for the search later this year, when the trackers will be working in a spectacularly lush area, which has the highest density of ungulates they’ve seen so far.
“Snare-sensitive species, like other large ungulates, are still frequently detected by camera traps,” she says. “So logic dictates that there could still be a few individual saola left.”
Carolyn Cowan is a staff writer for Mongabay.
Citations:
Nguyen, A. T., Nguyen, A., Le, M., Wilting, A., & Tilker, A. (2025). Camera-trapping reveals both defaunation and conservation priority species in an unprotected forest in Vietnam. Global Ecology and Conservation, 61, e03644. doi:10.1016/j.gecco.2025.e03644
Tilker, A., Niedballa, J., Viet, H. L., Abrams, J. F., Marescot, L., Wilkinson, N., … Wilting, A. (2024). Addressing the Southeast Asian snaring crisis: Impact of 11 years of snare removal in a biodiversity hotspot. Conservation Letters, 17(4). doi:10.1111/conl.13021
Garcia-Erill, G., Liu, S., Le, M. D., Hurley, M. M., Nguyen, H. D., Nguyen, D. Q., … Heller, R. (2025). Genomes of critically endangered saola are shaped by population structure and purging. Cell, 188(12), 3102-3116.e22. doi:10.1016/j.cell.2025.03.040
See related story:
Rare mammals caught on camera highlight value of Annamite Mountains
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