DNA probe links Japan’s otter-themed cafes to poaching hotspots in Thailand

A glut of social media videos featuring captive Asian small-clawed otters in the mid-2000s led to what wildlife trade experts term “the pet otter boom.” Demand for the species exploded, placing pressure on wild populations already contending with widespread loss of their wetland habitats. Amid an emerging trend for otter-themed exotic animal cafes in some of the world’s largest cities, experts worry the demand for live otters will intensify.

Researchers from France, Japan and Thailand recently used DNA tests to investigate the geographic origins of Asian small-clawed otters (Aonyx cinereus) held in exotic animal cafes in Japan. Their study, published in Conservation Science and Practice, links many of them with wild populations in well-known otter poaching hotspots in southern Thailand.

“Actually, there’s a lot more Thai otters in Japan than we previously thought,” said study co-author Worata Klinsawat, a conservation biologist at King Mongkut’s University of Technology Thonburi in Thailand. “Otters are now one of the top three mammals that people want to keep as exotic pets.”

The species, which ranges from South Asia across Southeast Asia, has been listed under Appendix I of CITES, the global wildlife trade convention, since 2019, which means the commercial trade in wild specimens is prohibited. It’s also protected by national laws within many countries in its range, including Thailand. However, it lacks legal protection in Indonesia and Vietnam, leaving loopholes that traffickers exploit to sell wild-caught animals. Consequently, many captive otters in destination countries like Japan have ambiguous origins.

Poaching hotspots in Thailand

In their study, the researchers analyzed DNA samples from 81 captive otters in Japan: 43 from zoos, 33 from exotic animal cafes in cities such as Kyoto and Tokyo, and five seized by customs authorities. They then compared them with genetic data from wild populations in Thailand, Malaysia and Singapore.

More than 90% of the cafe otters and those from seizures shared genetic signatures with wild populations in areas identified by police records as poaching hotspots in southern Thailand. One hotspot is located in riparian zones and wetlands along the Gulf of Thailand coastline; the other is near Thailand’s land border with Peninsular Malaysia. “Every time we talk to villagers, these two locations always pop up,” Worata said, noting her colleagues often find pet otters in homes while surveying the species’ natural habitat in southern Thailand. “They know that if you want a pet otter, you call people in these areas.”

There’s high demand for otters as pets in Thailand, despite national laws protecting them from capture and commercial breeding. Wild otters plucked from their habitats, likely in the two hotspots identified in the study, are typically sold online via social media groups and websites. The scale of this trade was revealed in a 2018 report led by wildlife trade watchdog TRAFFIC, which identified hundreds of online adverts featuring otters for sale in Indonesia, Thailand, Vietnam and Malaysia over just a four-month period.

The same report also highlighted seizure data that singled out Thailand as a major hub of otter trafficking in Southeast Asia. Of 59 otters that were confiscated in 13 busts between 2015 and 2017, mostly in Thailand and Indonesia, 32 of them were seized in transit from Thailand to Japan.

The new DNA study underscores Thailand’s role in the international otter trade. However, Worata was careful to point out the genetic evidence isn’t absolute proof that cafe otters sampled in Japan are victims of the illegal trade. Some may be captive-bred descendants from individuals imported from Thailand before the species was listed under CITES Appendix I in 2019, she said.

The study notes, however, that records kept in the CITES trade database indicate there were no legal imports of the species into Japan from Thailand since 1988. Therefore, the authors conclude that many of the cafe otters originating from southern Thailand entered Japan “likely through illegal trade after this date.”

Exotic animal cafes are a regulatory gray area, according to Worata. The researchers found that cafe owners typically didn’t possess detailed paperwork documenting the provenance of their animals. What’s more, the records they did possess often contradicted the DNA results, indicating dealers supplying otters to cafes might be concealing the animals’ true origins. “Sometimes the pedigree form indicated Indonesia as a source country,” Worata said, “but we found that it’s Thailand.”

In contrast, the researchers found most of the otters sampled from zoos were more genetically diverse, a trait the authors say suggests they are from well-regulated captive-breeding programs. Zoos also typically possessed thorough paperwork showing the origins of their animals, the study says.

Kanitha Krishnasamy, director for TRAFFIC in Southeast Asia, said the new study “provides good reason” for authorities to implement stricter monitoring of wildlife trade routes between Thailand and Japan. Krishnasamy, who wasn’t involved in the study, also noted that since much of the otter trade is conducted online, authorities should be investigating where and how digital dealers are sourcing their animals. “There should be a higher level of scrutiny of passenger luggage,” she said, “as this seems to be a popular method of smuggling live wild animals out of Thailand for the exotic pet market.”

Recent cases of otters smuggled on international passenger flights signal how little traffickers fear punishment. In one incident, two people smuggled more than 30 live animals, including two baby otters that later died, past airport security in Bangkok and onto a flight bound for Taiwan. The suspects were reportedly only arrested after several of the animals, which also included 28 baby tortoises and a marmot, escaped and were found crawling around the plane cabin.

More work needed to protect species

While DNA-based studies can help authorities target their efforts to where they’ll have most impact, more work is needed to improve their accuracy across the species’ entire range, Worata said. A lack of genetic information on wild otters beyond Thailand leaves sizable data gaps.

A vital next step will be expanding the genetic reference database across Southeast Asia, especially in trafficking-prone countries with weak regulations like Indonesia. To this end, Worata’s team are collaborating with researchers in Java to improve genetic records, an endeavor she plans to replicate in Malaysia and Vietnam should funding be available.

Educating people about why otters don’t make good pets is also a vital step, as well as encouraging those who keep them to return them to rescue centers so that they can be rehabilitated and released back into the wild.

As top predators, otters play a crucial role in maintaining the health of freshwater wetlands, mangroves and rivers by controlling prey and pest populations. Asian small-clawed otters are also sensitive to environmental degradation, such as pollution and habitat loss, so they can serve as important indicators of overall ecosystem health.

If they’re continually taken out of their environment to live in city apartments, cafes and people’s backyards, however, their crucial ecological role will be lost. There are also welfare issues associated with keeping wildlife in captivity.

“Otters are social animals so when they’re kept in captivity, they often show signs of anxiety,” Worata said. “We’ve seen cases where baby otters that were taken from the wild during their first few weeks cannot swim and they become really afraid of water. That’s a really sad behavior to see in an otter.

“It’s natural to feel affectionate towards otters, but we need to leave them in the wild so that they can fulfil their ecological role, for them and for us.”

Citation:

Fujihara, M., Suzuki, A., Klinsawat, W., Chutipong, W., Sarabian, C., Sigaud, M., … Inoue‐Murayama, M. (2025). Molecular tracing of the geographical origin of captive Asian small‐clawed otters in Japan. Conservation Science and Practice, 7(4). doi:10.1111/csp2.70010

This article by Carolyn Cowan was first published by Mongabay.com on 26 May 2025. Lead Image: Asian small-clawed otters range across South and Southeast Asia. Image by Rhett A. Butler for Mongabay.

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