Most people would be terrified of entering the waters with crocodiles, but not Sao Chan. Like others living in this jungle village, deep in the southwest CambodiaIn the remote Cardamom Mountains, the 73-year-old farmer says the Siamese crocodiles found in the waterways here can look ferocious, but they shouldn’t be feared. “If we approach them, they run away,” Chan says.
He is right. There have been extremely few reported attacks by Siamese crocodiles on humans worldwide, and apparently none in Cambodia. Instead, it’s the crocodiles that people have every reason to fear. Once common throughout Southeast Asia, the notoriously shy siamese crocodile, which can grow up to 10 feet long, has been hunted for decades for its skin and meat so much that by the early 1990s the species was thought to be extinct in the wild. The International Union for Conservation of Nature lists the species as critically endangered.
Some of them have survived in the Cardamoms, however, where scattered populations of reptileslikely numbering less than 200 people in total, they were rediscovered at the turn of the millennium. Since then, the local population has carried out regular patrols to protect themselves from poachers and other threats. “We think crocodiles are sacred,” says Chan, one of his area’s chief rangers. (Read about 400 baby Siamese crocodiles rescued from illegal wildlife trade.)
Although patrols and other conservation efforts have helped prevent the extinction of Siamese crocodiles, concerns about the species’ long-term survival remain as population numbers have remained largely stable since their rediscovery.
Now, however, the outlook for one of Earth’s rarest reptiles can finally improve. In 2022, conservationists introduced more Siamese crocodiles into the wild than ever before, not just in the cardamoms, but for the first time in a wildlife sanctuary in the north of the country, where the crocodiles were historically found. Advances in genetic testing have simplified the identification of crocodiles likely to be released, and satellite tracking of reintroduced crocodiles has improved protection efforts.
“We have a long way to go, but the potential return of the Siamese crocodile could be Cambodia’s most successful conservation story,” says Pablo Sinovaswho runs the Cambodia program for Fauna and Flora International, one of the non-profit organizations reintroducing animals.
Make hybrid crocodiles
From two dozen species of crocodilians in the world, seven are listed as critically endangered, including the Siamese crocodile. Its decline began with competition from rice farmers for wetland habitat, although it was commercial hunting to meet the global demand for skin and meat products that brought the species to the brink. extinction. (See a map of where crocodiles live around the world.)
Many wild-collected Siamese crocodiles were initially supplied to crocodile farms. At their peak in 2010, there were around 900 farms in Cambodia, collectively housing over 250,000 crocodiles. But with the decline in demand for crocodile skin products in recent years due to changing fashion trends and increase in agricultural coststhe country’s agricultural activity nearly collapsed.
Such conditions have left farmers like Aim Kim San, who runs a small crocodile farm near Tonle Sap Lake, on the outskirts of Siem Reap town, desperate to sell his farm. “Before, it was a really good deal,” said Kim, 65, standing on a catwalk above a dreary concrete enclosure filled with some of the farm’s 135 breeding crocodiles. “Now I want to quit and start selling motorcycle parts instead.”
It may seem like a good idea to release unwanted crocodiles from farms into the wild. But farmed Siamese crocodiles have largely lost their genetic distinction through interbreeding with salt water crocodile and Cuban crocodiles, a species introduced to Cambodia decades ago. This hybridization has made the traditionally shy Siamese crocodiles very aggressive and unfit for life in the wild.
In the past decade, most of the Siamese crocodiles Fauna and Flora International has released in the Cardamoms instead came from a small breeding program the organization runs near Phnom Penh, the Cambodian capital. But breeding Siamese crocodiles is a complicated process, and so far only about 130 crocodiles have been released into the cardamoms, with some also coming from farms.
Although this has helped increase the wild population to around 300 individuals, conservationists want to increase reintroduction rates to ensure genetic diversity and the species’ overall survival.. (See photos of what may be the biggest crocodile ever captured.)
A proven method is to perform DNA testing to identify more genetically pure Siamese crocodiles. Cambodian researchers can now carry out these tests in the country, rather than sending samples abroad. “It has simplified our work considerably,” says Sinovas, who is also National Geographic Explorer.
Deployment of data and monitoring tools
Patrol efforts in the Cardamoms have also become easier as illegal logging in the area has decreased. due to improved law enforcement and far fewer poachers target crocodiles. But threats persist, especially from local fishermen who can injure or even kill crocodiles while fishing.
Often, locals seem to warmly welcome efforts to save the crocodiles, especially since conservation spending in the area has helped support new infrastructure, including a Buddhist temple and school. Villagers are also financially rewarded for reporting sightings of crocodile nests and eggs. “I am happy to report if I see crocodiles in my rice fields, which I have already done twice,” says Srey Ny, a 78-year-old farmer, who remembers the time when not only Siamese crocodiles but also tigers were common in cardamoms.
The crocodiles released this year in the Cardamoms have for the first time been equipped with satellite trackers. Data showing that most animals stayed close to their release site.
Researchers have also started using eDNA technology to detect Siamese crocodiles in the wild. Despite its difficulties, the researchers detected environmental DNA left behind by the reptiles in 19 of the 21 settings. “This could be the starting point for a revolutionary new way to assess the presence of endangered crocodiles in the wild,” says Sinovas.
Rebalancing ecosystems
Earlier this year, the release of 15 Siamese crocodiles in the remote Siem Pang Wildlife Sanctuary in northern Cambodia marked the first time crocodiles were reintroduced anywhere in Cambodia outside of cardamoms.
The release, which was organized by a conservation group called Phoenix in resurrection, proved difficult, because, unlike the Cardamoms, the locals were suspicious. Since crocodiles had not been seen in the area for several decades, many residents near the release site were skeptical of introducing large predators to their local water sources.
Conservationists have spent many months trying to allay concerns. Eventually they did, and the crocodiles, which came from a farm and were genetically tested, were released into a wet pond. At first they stayed in a large wooden enclosure. But the enclosure was designed to break in heavy rain, allowing the crocodiles to swim in the canals of the wetlands.
As part of the pilot program, there are plans to release another 20 crocodiles at a nearby site in Siem Pang next year. “Ultimately, we want to see a self-sustaining population of Siamese crocodiles here as part of a healthy aquatic ecosystem,” said Jonathan Eames, CEO of Rising Phoenix.
Although Siamese crocodiles have always been part of Cambodia’s natural landscape, the impact of their reintroduction on fish and other wildlife is far from clear. “I would be amazed if an apex predator like this were introduced and we didn’t see dramatic changes in the ecosystem,” says Jack Eschenroedera fisheries biologist with the California-based conservation group FISHBIO, who helped study habitats for the release of crocodiles in Siem Pang and conducted some of the eDNA studies.
For his part, Sinovas of Fauna and Flora International sees the campaign to save the Siamese crocodile from the brink of extinction as part of a larger quest.
“Its survival is not just an ecological necessity, but a symbolic imperative if we have any hope of preserving nature on Earth,” he says.
Hush Chheana contributed reporting to Pur Boeung, Cambodia.
Stefan Lovgren works with the USAID-funded Wonders of the Mekong project. He and Zeb Hogan are the authors of the forthcoming book Chasing Giants: In Search of the World’s Largest Freshwater Fish.
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