Probe points to rule breach in Mauritius' lab monkey business
Mauritius says the sustainability assessments required under global regulations are ‘unwarranted’ in its trade of long-tailed macaques
Mauritius has supplied long-tailed macaques to the research industry since the 1980s. In recent years, the African island nation has taken a leading role in the lab monkey business as allegations of criminality in supply chains from Southeast Asian countries have led to increased demand elsewhere.
Now, the nonprofit Action for Primates has uncovered information that raises questions about the legitimacy of Mauritius’ trade in macaques.
In response to inquiries from Nedim Buyukmihci, Emeritus Professor of Veterinary Medicine at University of California-Davis and co-founder of Action for Primates, Mauritian officials indicated that sustainability assessments required under the regulatory regime for the macaque trade have not been done.
Failing to conduct these assessments would be a violation of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which regulates the trade in macaques. Considering this, Action for Primates has called on the treaty body to launch an investigation into the matter.
No NDF for Mauritius’ macaques?
The long-tailed macaque is an endangered species, according to a 2022 assessment by the International Union for Conservation of Nature (IUCN) Red List. It warned of a steep and rapid drop in the species’ global population, with a suspected decline of 40% in the last four decades.
Trade is among the drivers of the primate’s worsening predicament, the Red List assessors indicated. The long-tailed macaque is a heavily exploited species, primarily because they are used in research, including by companies testing the toxicity of drugs and other substances.
As I reported in The Ecologist, exporting countries reported over a million cross-border trades involving the primate between 2016 and 2021. These transactions included almost 259,000 live monkeys, as well as specimens of their body parts, such as blood and tissue.
The global macaque trade involves animals who are captured in the wild and individuals bred on farms. Monkeys originating from captive sources are most found in the trade. But reports and investigations indicate that laundering of wild-caught animals through captive facilities is a pressing issue in some Southeast Asian source countries.
Mauritius exports wild-caught and captive born or bred macaques. Captive born refers to monkeys who are born to wild parents in breeding farms, whereas captive bred means the offspring of individuals who were born in captivity.
Several companies have monkey farms on Mauritius and thousands of wild macaques are caught annually to use for breeding in these operations, the University of Mauritius’ Vincent Florens stated in 2022.
Mauritius has not carried out a comprehensive long-tailed macaque survey since the 1980s. Considering this and the species’ dire global conservation status, Action for Primates’ Buyukmihci has been seeking information about how the country determines that its lab monkey trade does not threaten the species’ wild population.
Mauritius is obliged to reckon with this question as a party to CITES. The treaty body regulates cross-border trade in around 40,000 threatened wild species of plants and animals, including the long-tailed macaque. Under its rules, countries should only approve exports of a species when trade will not negatively impact its survival in the wild. Moreover, where exports are approved, they must be “only in the volumes evidenced to be non-detrimental,” researchers highlighted in a 2022 paper.
To make this determination, countries are meant to carry out a sustainability assessment, known as a Non-Detriment Finding (NDF). CITES’ published guidance on NDFs specifies that these assessments are required for wild-sourced animals and plants, including individuals used as “parental stock” in breeding operations.
Yet, when Buyukmihci approached Mauritius’ CITES authorities – National Parks & Conservation Service (NPCS) – enquiring about NDFs for macaque exports, he was told they are not necessary.
“The Non Detriment Finding (NDF) for the wild monkeys in Mauritius is not warranted given that the population is an exotic invasive species and that extraction has no incidence in the wild,” wrote NPCS director Kevin Ruhomaun in an email on 23 May.
Call for investigation
Though macaques have lived in Mauritius for hundreds of years, they are considered an introduced species on the island. Colonialists displaced the primates from their native homes in Southeast Asia to Mauritius in the 1600s.
This impacts how they are viewed, according to Action for Primates’ co-founder Sarah Kite. Oftentimes, it’s assumed that “because long-tailed macaques are an introduced species in Mauritius, and they're labelled a pest, they don't deserve any conservation status,” she says.
But as far as NDFs are concerned, the primate’s introduced status is largely irrelevant, according to Sofie Flensborg, chief of the Legal Unit in the CITES Secretariat, which is the treaty’s administrative arm. In emailed comments to Buyukmihci, Flensborg said, “an NDF must be made for any export of a CITES-listed species, introduced or native.”
CITES is flexible about what NDFs consist of in practice, But the body has developed guidance that encourages countries to take a range of data into account when making NDFs, Flensborg explained in the email. This includes species’ population status, distribution and trends, and their conservation status.
Flensborg stressed that introduced species “pose specific challenges.” Accordingly, their NDFs consider factors like the role they play in local ecosystems, particularly if they are problematic. But the assessments for these species “must still determine that the export will not be detrimental to the survival of the species,” she said.
In his email to Buyukmihci, Ruhomaun stated that long-tailed macaques are “considered as a nuisance to the public,” resulting in hundreds of “monkey nuisance cases” lodged in recent years. The NPCS director also said studies show “wild monkey has been and is detrimental to the native fauna and flora in Mauritius,” including in the Black River Gorges National Park, where macaque numbers have considerably increased “during the past decades.”
Additionally, Ruhoman insisted that the country strictly regulates its macaque trade and has “set a clean record for the most humane export of monkeys.”
None of this gives Buyukmihci confidence that Mauritius is complying with its treaty obligations with regard to producing NDFs for the primate. So, he called on the CITES Secretariat to investigate the situation in an email on 2 June.
The Secretariat, whose duties include raising compliance issues with countries, is yet to respond to the request. I also contacted CITES but received no reply.
Domestic opposition
Buyukmihci has urged the Secretariat to examine Mauritus’ compliance with CITES rules on animal welfare in transport too. He said the primates have been subject to “inhumane and lengthy transportation times” in recent exports.
For instance, Mauritius transported 800 macaques to Miami on 13 May in a journey that lasted over 43 hours and involved seven flights and stop-overs, according to Buyukmihci.
Mauritian officials are also facing pressure domestically over allegations of poor welfare in the trade. In March, Linley Moothien, president of the animal welfare organisation 4 Tilapat, lodged complaints with multiple authorities over what he described as cramped and lengthy transport conditions for exported monkeys, as reported in Le Mauricien.
On 26 July, citizens took to streets of the capital Port Louis protesting macaque exploitation, including apparent government plans to permit pre-clinical testing on them in the country. As lexpress.mu reported, Moothien spoke at the event, vowing that the march was “only a first step towards a broader resistance.”
In 2024, 4 Tilapat produced a report on Mauritius’ trade in the primates. It made the case that macaques are subject to “distress, pain or suffering” across the trade chain, which is an offence under Mauritius’ 2013 Animal Welfare Act. Speaking with me at the time, Moothien pointed to the capturing process as an example of where suffering occurs.
As Science has reported, macaques are trapped in metal cages in and around villages, with breeding companies paying residents to allow traps on their land. But Moothien says “artisanal” methods are used in more remote locations, such as mountainous areas, as outlined in audio testimony he secured from a former farm worker. Here, trappers catch macaques in nets and holes in the ground, which causes injuries and mortalities, Moothien said.
An undercover investigation by French nonprofit OneVoice in 2023 also reported that many monkeys are killed on farms after capture and during the breeding phase, due to ill health.
Moothien told me that anecdotal evidence suggests the trade is lowering the macaque’s wild population. “People who live near forests and not far from mountains and hills say that some five years ago it was a normal thing to meet monkeys everywhere,” he said. But these people say macaques have since disappeared in many areas.
Mauritius’ 1980s survey estimated a population of 25,000-35,000 macaques. A further census is now underway, conducted by university researchers in collaboration with NPCS and some of the island nation’s breeding firms.
In March, one of the researchers, Raphael Reinegger, told Science that they have identified more suitable habitat for macaques than expected. On this basis, new estimates could end up being higher than those in the 1980s, he said.
But with only 2% of the primate’s habitat surveyed by then, the status of macaque populations in Mauritius presently remains an open question.
I approached NPCS for comment but none was received.
A disgrace
The fact that Mauritius has become a leading supplier of long-tailed macaques seemingly without the necessary NDFs conducted and a population census that dates to the 1980s is a stark illustration of where global wildlife trade regulation falls short.
Although NDFs are a CITES requirement, there is no routine scrutiny of them in the current system. Countries are not obliged to submit them to the Secretariat, although some states do voluntarily add them to a dedicated database that CITES maintains.
Due to this, Wildlife Conservation Society’s vice president of international policy, Susan Lieberman, suspects that NDFs are lacking in a “significant proportion” of cases, as I reported in The Revelator. Lieberman also told me that countries can ask to see exporting nations’ NDFs before allowing imports, although this is likely inconsistent too.
A case in point: the UK has not consulted Mauritius’ CITES authorities when making its own sustainability assessments about the African nation’s macaque trade in recent years.
The UK is a significant importer of long-tailed macaques, many of whom originate from Mauritius. It does its own NDFs for imports of the primate, which is a stricter measure than CITES provisions demand.
In October 2023, I obtained a copy of the UK’s “general” NDF for Mauritius’ macaques from the Joint Nature Conservation Committee (JNCC) through Freedom of Information requests. JNCC is the country’s CITES Scientific Authority for fauna and develops these assessments.
Produced in June 2020, this NDF remained a key piece of evidence relied on by JNCC in 2023 to inform its advice to the UK CITES Management Authority – the Animal and Plant Health Agency – about whether import applications met legal requirements for trade in the species. This was confirmed in other materials that JNCC provided to me in its responses, namely summaries of its advice.
The NDF contained information on the long-tailed macaque’s biology, distribution, and conservation status at a global level. It also contained a dedicated section about Mauritius’ population and the potential impact of trade on their numbers.
The overall document contained multiple references but only two in the Mauritius-focused section. One was for the CITES Trade Database, from which JNCC sourced figures for Mauritius’ exports of live long-tailed macaques.
The other cited source was a memorandum submitted to a UK parliamentary committee in 2009 by the Mauritian Cyno Breeders Association (CBA) and Noveprim, a primate breeding company. It characterised Mauritius’ macaque population as stable and unaffected by trapping for use in trade.
In 2009, the EU was revising a Directive on protecting animals in science and proposed to limit the bloc’s use of non-human primates to only captive-bred individuals.
Mauritius’ primate breeding companies were not in favour of the proposal and the submissions in the memorandum “were part of a lobbying attempt to persuade the European Union not to adopt a policy to move towards only allowing captive bred macaques,” says Action for Primate’s Kite.
She described the NDF as a “disgrace” due to its heavy reliance on “severely outdated” information from primate traders, rather than up-to-date sources and data, including material provided by the Mauritian government.
I approached the CBA for comment but none was received.
100% Mauritian
In emailed comments on 30 July, JNCC’s Directors of International Evidence and Advice, Beth Stoker and Natalie Askew, said the committee considers a variety of information when developing NDFs, such as scientific literature, consultations with experts and other CITES Authorities, and NDFs from source countries “where available.”
The 2009 memorandum “was treated by JNCC as important information to consider, provided by relevant stakeholders,” they said, adding “this was not the only source used and the NDF has been reviewed since, most recently in February 2025.”
“Given the information available to us, consultation with the Mauritian CITES Authorities was not considered necessary at the current time,” Stoker and Askew stated.
The level of consultation and period for review of NDFs varies depending on factors like species’ specific characteristics and their vulnerability, according to the JNCC staffers. The pair described NDFs as “living documents” that can be altered at any time “based on new evidence.”
“All applications referred to us are considered on a case-by-case basis taking into account existing NDFs and any new information,” they added.
New information that has come to light since JNCC’s 2020 NDF includes a “resurgence of the wild-caught trade” from Mauritius and an escalation in overall export numbers, up from 7,691 macaques in 2019 to 14,623 in 2024, says Kite.
These factors will “have an impact on the wild population,” she warns.
The long-tailed macaque’s worsening conservation status is another important development. However, Stoker and Askew stressed that while JNCC recognises the primate’s Endangered classification in the IUCN Red List, “its aim is to assess the risk of extinction of populations of wild species where they naturally occur.”
“Mauritius is not part of the species’ natural range,” they continued, with the primate being an “invasive alien species” there which has negative impacts on native biodiversity and commercial sectors, such as by foraging native plants and cultivated crops.
On the other hand, some researchers argue that though it is true that frameworks like the IUCN Red List largely ignore introduced populations of species, there is conservation value in adopting a more inclusive approach. Including these populations in global threat assessments can provide “a more accurate assessment of actual global extinction risk among species,” they wrote in 2023 paper.
.jpg){kind=link}
The researchers made the point that conserving introduced populations could help to prevent extinctions, particularly where species are facing pressing threats in their native range. This is a salient point for the long-tailed macaque as a 2023 estimate found the species may have declined by 80% in Southeast Asia over the last 35 years – an even worse situation than the 2022 Red List assessment indicated.
“Accounting for migrant species in conservation is not to dismiss potential conflicts with resident taxa and broader ecosystem-level effects but to reveal the novel ecological processes and conservation opportunities of our time,” the researchers stressed.
Even if population control is necessary, Action for Primates insists that “humane and sustainable” alternative methods to the commercial exploitation of macaques should be developed in Mauritius.
Some non-exploitative alternatives already exist, such as the provision of predator-proof nesting boxes to limit predation of native bird eggs by macaques and other animals.
In his report, Moothien also suggested that behaviour change among people matters by stressing that most deforestation and biodiversity destruction on the island is a result of human intervention.
As for the idea that the primates are ‘aliens’, Moothien is adamant: after 400 years of residing on the island, long-tailed macaques are now 100% Mauritian.
Je suis 1 activiste militant a Maurice et vit au milieu des macaques sur la montagne ORY,