Slow lorises, with their wide eyes and plump bodies, are one of the world\u2019s most trafficked primates. Despite their\u00a0venomous bite\u00a0that can prove\u00a0fatal to people\u00a0and their nocturnal habits, they\u2019re highly sought after in the pet trade and for use as tourist photo props \u2014 a demand\u00a0fueled by ill-informed social media videos\u00a0displaying them in domestic settings or captivity.<\/p>\n
All nine slow loris species, which range across South and Southeast Asia, are also threatened by deforestation and poachers who kill them for use in traditional medicines. A\u00a02010 study\u00a0found lorises were the most in-demand animal in traditional medicine stores in Cambodia.<\/p>\n
Tragically, these pressures act in synergy. Habitat loss pushes lorises closer to forest edges and humans, who at best mistakenly think them lost and take them into captivity with a view to relocating them to a habitat that\u2019s more \u201cwild.\u201d At worst, poachers take advantage of lorises\u2019 natural defense response \u2014 to freeze rather than flee.<\/p>\n
\u201cPickers go around and pick each one off the tree trunks and put them in a crate and they go off to market,\u201d Anna Nekaris, a professor of ecology, conservation and the environment at Anglia Ruskin University in the U.K. and a co-author of the study, told Mongabay. \u201cIt\u2019s crazy the large numbers that can turn up in confiscations.\u201d<\/p>\n
The IUCN, the global wildlife conservation authority, classifies all nine slow loris species as either critically endangered, endangered or vulnerable to extinction.<\/p>\n
Their threatened conservation status, coupled with their popularity on social media and prevalence in the illegal trade and law enforcement confiscations, make slow lorises a popular species for rescue and release projects.<\/p>\n
According to the new study from Bangladesh, however, even well-intentioned releases can result in premature deaths. \u201cIt\u2019s assumed that returning confiscated or rescued animals to the wild is always a positive conservation story,\u201d Nekaris said. \u201cBut for animals such as the Bengal slow loris, this is not always the best course of action.\u201d<\/p>\n The study took place in Lawachara National Park, a subtropical semi-evergreen forest extending across 1,250 hectares (3,090 acres) in northeastern Bangladesh. Although very little old-growth forest remains in the reserve \u2014 much of it has been degraded by historical logging \u2014 Lawachara is a flagship site for wildlife releases in Bangladesh, with park records showing 14 slow lorises had been liberated into the area during the three years preceding the study.<\/p>\n Between July 2022 and September 2023, the researchers worked alongside wildlife authorities to rewild the nine Bengal slow lorises following the standard loris release protocols used by the Bangladesh Forest Department (BFD). All of them had been confiscated from the trade and rehabilitated at the Jankichara Wildlife Rescue Centre in Lawachara.<\/p>\n With the help of radio transmitters fitted to each loris prior to release, the researchers tracked the lorises for eight months, across a total 138 nights, monitoring their behaviors, such as alertness, aggression, feeding, resting, and movement through the landscape.<\/p>\n Out of the nine lorises released, only two survived. Three died within just 10 days, and another four within six months. The researchers managed to recover the bodies of four of the dead lorises, finding lethal attack marks on their bodies.<\/p>\n Slow lorises are highly territorial and will fiercely defend their grounds, even to the death. As the world\u2019s only venomous primate, they have sharp teeth they use to inject venom. The bite wounds on the heads, face and digits of four loris bodies recovered indicated they\u2019d perished in territorial conflicts, most likely with wild slow lorises already living in the area.<\/p>\n \u201cThe fact these animals died of venomous bites shows how aggressive they are as a species,\u201d Nekaris said. It\u2019s yet further evidence of how dangerous and unsuitable they are as pets, she added.<\/p>\n The team also observed that released lorises were more alert and moved more than typical wild Bengal slow lorises. The two individuals that survived established larger home ranges compared to those that died, suggesting their success depended on moving away from the established territories of other slow lorises and avoiding attack. Lorises that had spent longer in captivity prior to release also survived for fewer days in the wild.<\/p>\n \u201cOur research shows that for highly territorial species like slow lorises, releasing them into areas that are already densely populated can be a death trap,\u201d Nekaris said. \u201cWithout fully understanding the animal\u2019s behavior, its time spent in captivity and the density of resident populations at the release site, reintroductions may do more harm than good.\u201d<\/p>\n Hassan Al-Razi, lead author of the study and team leader at Plumploris e.V., a Germany-based nonprofit rehabilitating lorises at the Jankichara Wildlife Rescue Centre, said Lawachara National Park has likely reached a saturation point, with most slow loris territories already occupied, rendering it unsuitable for further loris releases.<\/p>\n \u201cFor forest-dwelling species [in Bangladesh], release sites are often selected based on logistical convenience rather than ecological suitability,\u201d Al-Razi said. \u201cAs a result, certain forests have effectively become dumping grounds for rescued animals and are no longer appropriate release sites.\u201d<\/p>\n Jahidul Kabir, deputy chief conservator of forests at the Bangladesh Forest Department and a co-author of the study, told Mongabay that Bangladesh has rigorous release protocols for more charismatic species, such as tigers and elephants. However, no such guidelines exist for slow lorises, he said, which are generally little-studied and poorly understood among wildlife authorities in the country.<\/p>\n \u201cAfter these lessons, we realize that we need to develop a release protocol for the slow loris,\u201d Kabir said, starting with assessing the overall population size and carrying capacity of lorises in Lawachara National Park. When it comes to considering further releases, he said a cautious, data-driven approach could help prevent further release-related mortality. \u201cWe need to move forward very carefully,\u201d he said.<\/p>\n Nekaris, who is vice chair of the IUCN\u2019s Primate Specialist Group, said work is underway to plug knowledge gaps on lorises and other nocturnal, territorial species, and to draw up species-specific guidelines for rehabilitation and translocations.<\/p>\n \u201cWe are working on species and countrywide guidelines for captive management, translocation, reintroduction, rescue center care, study in the wild, taxonomy and education, and outreach and health,\u201d she said.<\/p>\n The researchers say their findings can be used to help avert losses across loris range countries in the short term. They make several recommendations to enhance the effectiveness of releases, including thorough site assessments to survey the existing wild populations at potential release sites; obtaining a good understanding of the species and individuals to be released; and only releasing animals under the surveillance of rigorous post-release monitoring.<\/p>\n The latter is crucial, experts say, to understand survival rates, adapt release strategies, and identify when animals enter unsuitable habitats, such as areas prone to hunting or encroachment.<\/p>\n Conservationists at the IAR Indonesia Foundation (YIARI) have been rehabilitating and releasing critically endangered Javan slow lorises (Nycticebus javanicus<\/em>) for 15 years. They\u2019ve learned that post-release monitoring is critical to the success of releases.<\/p>\n \u201cWithout monitoring, we cannot understand survival rates, causes of mortality, territorial conflict, dispersal patterns, or habitat use,\u201d Richard Moore, senior adviser at YIARI, told Mongabay in an email. \u201cMonitoring allows us to refine protocols over time, define suitable release-site characteristics, and improve success rates based on evidence rather than assumptions.\u201d<\/p>\n Moore said loris survival rates in Java, the most densely populated island in Indonesia, are often higher in secondary forests and agroforestry plantations than in primary forest. \u201cSlow lorises found in trade are more likely to originate from forest edges, gardens, and plantations outside protected [areas], where densities are higher and capture is easier,\u201d he said, noting this means animals from captive backgrounds might be more comfortable in these more disturbed habitats.<\/p>\n However, finding these types of areas that are safe from hunting pressure and illegal encroachment, as well as free of wild slow lorises that would fiercely defend their territories against newcomers, is a constant dilemma. \u201cHabitats that best match the rescued animals\u2019 ecological preferences may carry higher human risk,\u201d Moore said.<\/p>\n This underscores the need for careful and evidence-based selection of release sites to avoid animals being liberated into areas that bear little resemblance to the habitats in which they were once living before capture.<\/p>\n As in the Bangladesh study, YIARI has also observed that prolonged time spent in captivity in rehabilitation reduces lorises\u2019 chances of survival in the wild. \u201cFor this reason, release should take place as soon as an animal meets strict health and behavioural criteria, rather than extending captivity unnecessarily,\u201d Moore said.<\/p>\n Given the myriad challenges of releasing individual lorises, and the fact that many wildlife rescue facilities struggle from a lack of funding that can lead to them releasing animals prematurely, experts say rescue, rehabilitation and release should be viewed as one component of a broader conservation strategy that seeks stop animals being poached from the wild in the first place.<\/p>\n \u201cRRR [Rescue, Rehabilitation and Release] addresses the symptoms of the crisis \u2014 confiscated individuals from the illegal pet trade \u2014 rather than the underlying driver, which is illegal wildlife trade itself,\u201d Moore said.<\/p>\n While well-managed wildlife rescue centers equipped to care for and release animals support law enforcers\u2019 capacity to conduct seizures, and thereby increase the perceived risk for traffickers, Moore said the ultimate aim is to eliminate the need for them altogether. \u201cThe goal is not to perfect release methods indefinitely, but to reduce trade pressure to the point where large-scale rescue and release become unnecessary,\u201d he said.<\/p>\n For Nekaris, the findings from Bangladesh underscore what\u2019s at stake once a loris is plucked from the wild and plied into the illegal trade.<\/p>\n \u201cThe illegal wildlife trade is often likened to the cut-flower industry,\u201d she said. \u201cWhen you take an animal out of the wild, even though it\u2019s still alive, it no longer has an ecological function.\u201d<\/p>\n If that individual then can\u2019t survive after release, or creates conflict for the local wild population, then it may be better not to return it to the wild at all, she said.<\/p>\n \u201cYou have the two sides, you have the conservation of the species, and the welfare of the individual, and we fall in love with these individuals,\u201d Nekaris said. \u201cBut if releasing them to the wild has negative impacts on their species, that individual may have to be sacrificed.\u201d<\/p>\n Al-Razi, H., Maria, M., Rabbi, R. A., Shimu, M. S., Rahman, S., Sultana, R., \u2026 Nekaris, K. (2026). A new home is a death trap: Reinforcement at a translocation release site leads to fatalities in an endangered primate species.\u00a0Global Ecology and Conservation<\/em>, e04072. doi:10.1016\/j.gecco.2026.e04072<\/a><\/p>\n Starr, C., Nekaris, K., Streicher, U., & Leung, L. (2010). Traditional use of slow lorises\u00a0Nycticebus bengalensis<\/em>\u00a0and\u00a0N. pygmaeus<\/em>\u00a0in Cambodia: An impediment to their conservation.\u00a0Endangered Species Research<\/em>,\u00a012<\/em>(1), 17-23. doi:10.3354\/esr00285<\/a><\/p>\nThe toll of territorial conflict<\/strong><\/h3>\n
\u2018Dumping grounds\u2019 for confiscated wildlife<\/strong><\/h3>\n
Evidence-based release and monitoring<\/strong><\/h3>\n
Address the underlying driver: The illegal wildlife trade<\/strong><\/h3>\n
Citations:<\/strong><\/h2>\n
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