Data discrepancies suggest Laos monkey smuggling persists, despite trade ban

BANGKOK — A new report published on Feb. 18 detailed widespread discrepancies in data provided from Southeast Asia’s long-tailed macaque breeding farms, highlighting how monkey trafficking is able to slip through the regulatory cracks put in place by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

Although the report was published anonymously by Sandy River Research, the data it draws from are referenced and largely available to the public across disparate sources. Mongabay has not been able to independently verify the identity of the authors, and Sandy River Research’s website states it will not be commenting further on the report.

The report’s findings paint a bleak picture for endangered long-tailed macaques (Macaca fascicularis) that appear to be poached from the wild across the Mekong region before being laundered into breeding farms across Cambodia, Laos and Vietnam. From here, the monkeys are kept in often grim conditions before being exported to biomedical research laboratories, primarily in Europe, the United States, Canada, Japan and South Korea.

These laboratories purchase macaques at scale, often for tens of thousands of dollars per head, while poachers across Southeast Asia scrape together a living plucking the monkeys from the wild. All of this, the biomedical research industry says, is necessary to develop life-saving drugs, despite existing and in-development alternatives such biosimulations, computational models, diagnostic imaging and organ-on-a-chip technology — artificial systems that function in the same way as human tissue or organs.

Over the past two decades, multiple institutions have called into question the efficacy of animal testing, including the U.S. Food and Drug Administration, which estimated in 2004 that 92% of drugs passing animal testing trials fail to make it to market. The issue has been hotly contested among scientists, animal rights activists and conservationists as the ethics of the biomedical research industry have been called into question.

Proponents of animal testing say that crucial drugs, like the COVID-19 vaccines, wouldn’t be possible without testing on long-tailed macaques, and the industry consistently lobbies to prevent the species from being protected by conservation and wildlife laws — even attempting to reverse the long-tailed macaque’s 2022 endangered listing on the IUCN Red List. Efficacy aside, the monkey trade is big business, with each shipment from Southeast Asia valued often in the hundreds of thousands of dollars, sometimes even millions.

Cambodia exported more than 170,000 live long-tailed macaques between 2019 and 2023, while Vietnam exported more than 45,000 in the same period, according to CITES trade data. Shipping records seen by Mongabay indicate that monkeys exported from Vietnam in January were valued between $1,100 and $10,000 per head.

With so much at stake, the Sandy River Research report offers an insight into a multibillion-dollar industry that relies on the exploitation of long-tailed macaques, their habitats, and the weak regulatory oversight of countries home to the species.

Taken in Thailand

Due to its lack of licensed monkey breeding farms, Thailand only gets a cursory mention in the Sandy River Research report, but it’s noted as a “hunting ground” for long-tailed macaques, many of which live in semiurban environments.

By contrast to Cambodia, where the largest populations of long-tailed macaques live along rivers deep within protected forests that require poachers to trek, often for days, to trap and smuggle out monkeys, Thailand offers fertile grounds for poachers who often work in gangs to blow-dart the species on the side of roads or near tourist and residential sites.

Drawing from local media reports, the Sandy River Research report highlights what appears to be a spike over the course of 2023 in seizures of long-tailed macaques by Thai authorities as poachers were attempting to smuggle monkeys into Cambodia and Laos, often by crossing the Mekong River.

Out of the 19 stories compiled in the Sandy River Research report, 14 were published in 2023, but conservationists warn that there are likely more seizures and more successful cross-border smuggling of long-tailed macaques in Thailand than what’s being reported.

Tom Taylor, chief operating officer at Wildlife Friends Foundation Thailand, told Mongabay in a phone interview that “The problem in Thailand is bigger than what the international media is seeing and more long-tailed macaques are going from here to Laos and Cambodia.”

Unlike Malaysia or Indonesia, Thailand doesn’t conduct culls of long-tailed macaques, although the species is regarded as a pest across all three countries. So while Taylor detailed WFFT’s desexing campaigns aimed to humanely reduce the urban long-tailed macaque populations in Thailand, he noted that the negative coverage of the species in urban Thailand has coincided with seizures at the borders where authorities have busted monkey smugglers.

“It’s so easy to find and to catch long-tailed macaques in Thailand, you can find them by the side of the road where people feed them, so it makes sense that people are trying this if the wild population is declining in Cambodia,” he said. “What we see is gangs darting the monkeys, bundling them into these blue mesh bags and then placing them in cars, vans, under buses, and driving them over the border into Laos and Cambodia.”

WFFT has conducted interviews with monkey traders over the years and have seen the Mekong River emerge as a hotspot for criminality, with the illegal wildlife trade often overlapping with other criminal activities in the region.

“I fully believe that long-tailed macaques are being trafficked into Laos and Cambodia,” Taylor said. “The mechanisms in place — identification methods such as tattooing, facial recognition, etc. — are not enough to prevent the laundering of monkeys through breeding farms.”

Last stop, Laos

These farms are proliferating in Laos, despite CITES having banned the international trade of long-tailed macaques from Laos in 2016. The ban was lifted in 2022, only to be reinstated again in 2023 due to allegations of monkey laundering. These concerns have continued into 2025 regarding the falsification of trade permits that enabled an import of monkeys allegedly from Myanmar into Laos.

“Five new breeding facilities have been established since 2021 and are at different stages in the development of their captive-breeding programs,” the CITES Secretariat wrote in its report ahead of the January 2025 meeting of its Standing Committee. “However, it is not fully clear which facility is sourcing its breeding stock from other captive-breeding operations, and which is sourcing it from the wild. It is equally unclear whether wild caught specimens are being added to the current breeding stocks of established operations.”

But beyond the contention over Laos’s breeding facilities, conservationists are questioning more fundamental matters in Laos: for example, just how many long-tailed macaques remain in the wild? Previous estimates have hovered around the 300-500 mark until at least 2022, and although these numbers have been used by CITES, the IUCN and other scientific bodies, no extensive survey has been conducted to produce a better estimate.

Ahead of the 2025 CITES meeting, Laotian authorities submitted a nondetriment findings report to CITES stating that the wild population of long-tailed macaques was now estimated to be 30,586 individuals — a number generated from a March 2024 study published by the National University of Laos, which is also Laos’s national CITES scientific authority. Two of the study’s authors are focal points for Laos’s CITES scientific authority: Sithong Thongmanivong, who is also vice dean of the university, and Thananh Khotpathoom, who heads the university’s postgraduate division.

Neither responded to questions sent by Mongabay regarding the study, whether it was financed by monkey trading companies, or how it concluded that Laos’s wild long-tailed macaque population had grown so dramatically.

K. Yoganand, an independent researcher and former regional lead for wildlife and wildlife crime at WWF, told Mongabay that the latest estimate of the wild long-tailed macaque population in Laos appears to be a gross overestimate and that there are several inconsistencies in the methods used and the results presented.

“It is possible that the research team largely surveyed riparian areas, which are the known prime habitats for long-tailed macaques in Laos, but applied those sighting rates to a wider area across southern Laos,” Yoganand said in a phone interview. “But again, the report is very sketchy and unclear to make a good assessment.”

Yoganand cautioned that a biased sampling in the best monkey habitats and assuming that similar densities can be found in other habitats can lead to an inflated population estimate. He also said wildlife hunting is rife in Laos and so areas that weren’t sampled may be devoid of wildlife, even if they have the characteristics of good habitats.

“From the survey reports I have read over the years, the discussions I have had with primate researchers in Laos, and from my field observations, I can say that there are not a lot of long-tailed macaques left in the wild in Laos. Also, we hardly ever get government or industry data on the capture rate [from the wild] so we can’t accurately assess whether the macaque trade is biologically sustainable or not,” Yoganand said.

“When there is such uncertainty, it is essential to apply the precautionary principle and consider it unsustainable until definitively proven otherwise,” he added.

A Laotian plan to legalize monkey laundering?

As such, if the wild population of long-tailed macaques in Laos has been exaggerated, it’s the breeding facilities that stand to benefit.

Documents seen by Mongabay suggest that on July 25, 2023, Laos’s Department of Forestry formed a committee to regulate and develop standard operating procedures for catching wild long-tailed macaques. The government’s plan to approve the capture of monkeys from the wild was developed shortly after Japanese pharmaceutical conglomerate Shin Nippon Biomedical Lab (SNBL) entered into a partnership with Laos’s Sokxay Group, with SNBL Sokxay, a joint venture, incorporated on May 16, 2023.

Since then, the March 2024 study has claimed there are more than 30,000 long-tailed macaques living in the wild. In April 2024, the Department of Forestry downlisted the species to Category II, which legalizes capture from the wild.

Per a report submitted to the CITES Secretariat by Laotian authorities in September 2024, SNBL Sokxay is the only breeding facility capturing long-tailed macaques from the wild in Laos.

SNBL did not reply to questions sent by Mongabay regarding the capture of long-tailed macaques or its role in the March 2024 study and the shift in wildlife legislation regarding the species’ protected status.

The CITES Secretariat appears to be convinced of Laos’s revised population estimate, and in January 2025 called the results “comprehensive and robust, involving detailed population estimates based on actual field surveys.”

However, the full nondetriment finding has not been publicly shared, and experts question whether it has been subjected to scientific scrutiny.

“It’s intriguing to see that the CITES Secretariat is impressed with this dubious estimate [of wild long-tailed macaque population in Laos],” Yoganand said, calling on CITES to allow for an independent scientific review of the study, rather than simply taking the study at face value.

The CITES Secretariat declined to answer specific questions regarding discrepancies in data from Laos, but noted that recommendations regarding the trade from Laos will be reviewed at the November 2025 CITES meeting in Uzbekistan.

“In general, it is a pathetic state of affairs that such unreliable estimations are routinely being used as a basis to assess the sustainability of trade in endangered species,” Yoganand said. “When an error in judgment can easily push the species further toward extinction.”

Laos’s long history of porous borders, corruption and wildlife smuggling — including of monkeys — could allow monkey traders, breeders and the biomedical research industry to claim that smuggled monkeys were legally caught in the wild and originate from Laos. Indeed, Laos’s government has already said that a capture rate of 5% should not impact the wild population of long-tailed macaques, but this rests on the idea that the wild population estimate of 30,586 individuals is accurate and that the population growth rate, sex ratio and other demographic factors are understood.

“This lack of transparency is a constant at the CITES Secretariat, they don’t want to address some of these very controversial issues, instead they want to be politically correct and not offend any governments,” said Karl Ammann, a veteran conservationist and director of The Tiger Mafia, a documentary filmed over 10 years investigating the illegal wildlife trade across Southeast Asia and beyond.

Smuggling routes from Thailand into Laos have existed for years, Ammann said, with a wide range of wildlife, including monkeys, trafficked into Laos over the Mekong River — not by bridges, but by boat at night. This trade route is so brazen that even caged tigers have been known to be shipped across the Mekong. When asked about whether Laos’s significantly increased estimate of wild long-tailed macaques would help monkey-laundering operations at breeding facilities, Ammann said it was “pretty obvious.”

The scale of the illegal wildlife trade in Laos and neighboring countries is so vast and so open that CITES “is being fooled left, right and center,” Ammann warned, noting that despite evidence of monkey laundering, along with tiger farming and elephant trafficking, the Laotian government is still trying to rehabilitate its image and regain its access to the international endangered species market.

“Their [CITES] outlook is that they’re a trade organization, not a conservation organization,” he said. “And yes, trade can be beneficial to wildlife conservation if it’s handled sustainably and well, but Laos is a very typical example of when it isn’t.”

Banner image: Long-tailed macaques being held at Sookvannaseng Integrated’s breeding farm in Bolikhamsai province, Laos. Image supplied by source.

Citations:

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Godlee, F. (2014). How predictive and productive is animal research?. BMJ: British Medical Journal, 348. doi:10.1136/bmj.g3719

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