Slow lorises are nocturnal strepsirrhine primates in the genus Nycticebus that live in the rainforests of South and Southeast Asia. They are threatened by habitat loss and fragmentation from deforestation, selective logging, and slash-and-burn agriculture, as well as by collection and hunting for the wildlife trade, including the exotic pet trade, and for use in traditional medicine and as bushmeat. Because of these and other threats, all five species of slow loris are listed as either "Vulnerable" or "Endangered" by the International Union for Conservation of Nature (IUCN). Their conservation status was originally listed as "Least Concern" in 2000 because of imprecise population surveys and the frequency in which these primates were found in animal markets. Because of their rapidly declining populations and local extinctions, their status was updated and in 2007 the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) elevated them to Appendix I, which prohibits international commercial trade. Local laws also protect slow lorises from hunting and trade, but enforcement is lacking in most areas.
Traditional beliefs regarding slow lorises have been part of the folklore of Southeast Asia for at least several hundred years. Their remains are buried under houses and roads to bring good fortune, and every part of their body is used in traditional medicine to make products ranging from love potions to unproven cures for cancer, leprosy, epilepsy, and sexually transmitted diseases. The primary users of this traditional medicine are urban, middle-aged women who are reluctant to consider alternatives.
Despite being poor pets that are difficult to care for, with a dangerous toxic bite and a sleep cycle opposite to that of humans, a large number of slow lorises are traded as pets, both locally and internationally. Although it is illegal to import slow lorises for commercial sale, they are popular exotic pets in their native range, Japan and parts of Europe. This is mainly because of their "cute" appearance, popularized in highly viewed YouTube videos, which is due in part to their large eyes, adaptations to a nocturnal lifestyle. Hundreds of slow lorises have been confiscated at airports, but because they are easy to hide, these numbers are likely to be only a small fraction of the total number being trafficked. Traders cut or pull the teeth of slow lorises to make them appear to be an appropriate pet for small children, but this practice often leads to extreme blood loss, infection, and death. Slow lorises lacking their teeth would be unable to fend for themselves and therefore are not reintroduced into the wild. Most captive lorises in the pet trade also receive improper care and die from poor nutrition, stress, or infection. Despite this, demand has risen, and slow lorises are no longer captured opportunistically, but are now hunted on a commercial scale using flashlights, from which the animals do not flee.
Connected protected areas are important for the conservation of slow lorises because these primates are not adapted to travel long distances on the ground. Training for enforcement officials helps improve identification and the awareness of their legal protection. Sanctuaries and rescue facilities are available to provide both temporary and lifelong care for confiscated slow lorises. Zoo populations of some species have not bred much and have grown too old to reproduce, although the pygmy slow loris is doing well at some facilities, such as the San Diego Zoo.
Background Slow lorises (genus Nycticebus) are primates that belong to the suborder Strepsirrhini. They are found throughout South and Southeast Asia and the surrounding islands, and live in the upper canopy of tropical rainforests. They are nocturnal, sleeping during the day curled up in the fork of a tree. Slow lorises are slow and deliberate climbers and rarely come to the ground. They have a round face, woolly fur, a dark stripe down their back, and a tail that is reduced to a stump. Their head and body length ranges from . Their hands and feet are strong and good at grasping for long periods of time. Slow lorises are either solitary or live in pairs; the males are territorial and mark their territories with urine. Their diet consists of mollusks, small vertebrates, and fruit.
Slow lorises can produce a secretion on their brachial gland (a gland on their arm) which when mixed with their saliva creates a volatile, noxious toxin that can be, if necessary, delivered in a bite to an aggressor. A bite causes a painful swelling and is slow to heal; the toxin is mild and not typically fatal, although an anaphylactic reaction is possible.
Five species are currently recognized. The Javan slow loris (N. javanicus) is native to the Indonesian island of Java, whereas the Bornean slow loris (N. menagensis) can be found on Borneo and nearby islands, including the Sulu Islands in the Philippines. The Sunda slow loris is found on the Indonesian island of Sumatra as well as Peninsular Malaysia, Singapore, and Thailand. The other two species are found entirely on the mainland, with the Bengal slow loris (N. bengalensis) native to Bangladesh, Cambodia, southern China, Northeast India, Laos, Myanmar, Thailand, and Vietnam and the pygmy slow loris (N. pygmaeus) found in Cambodia, Laos, Vietnam, and southern China. Nekaris and Nijman (2022) combined morphological, behavioural, karyotypical and genetic data and suggested that pygmy lorises are best placed in their own genus, Xanthonycticebus.
Threats in the wild
Slow lorises are threatened by deforestation and the wildlife trade, which includes the exotic pet trade, traditional medicine, and bushmeat. Other threats includes road construction, selective logging, and slash and burn agriculture. Habitat fragmentation obstructs biological dispersal for these species that rely on vines and lianas to move from tree to tree. Consequently, slow lorises are found dead on power lines or are victims of roadkill in areas where roads cut between forest patches.
All species are listed either as "Vulnerable" or "Endangered" by the International Union for Conservation of Nature (IUCN). Populations are rapidly declining, and their distribution is becoming patchy because of local extinctions throughout their range. Although all species are protected by law in every country in which they occur, conservation efforts are hindered by a lack of public awareness, since many local villagers and remoter buyers of captive specimens are unaware of their endangered status. Recognition and awareness of slow lorises is even low among national park staff. In places like Vietnam, where these nocturnal primates have commonly been found, most local villagers were not familiar with them when shown photos. Only a few older hunters recognized them, but pointed out that they had not seen them in more than 10 or 15 years.
Traditionally, the slow lorises were thought to consist of very few species and were considered to be common across Southeast Asia. These assumptions were due to their nocturnal behavior and their high frequency of occurrence in animal markets throughout the region. Furthermore, researchers from the 20th century and earlier perpetuated the notion that slow lorises were common by reporting them as either present or absent rather than noting low population densities in their field research. As a result, slow lorises were seldom studied, resulting in the initial "Lower Risk/least concern" (LR/lc) conservation status assessment on the IUCN Red List (version 2.3) in 2000. Even in the mid-2000s, population estimates were based only on small surveys.
In 2009, primatologist James Thorn used environmental niche modelling in Indonesia to supplement the poor population data gathered to date to predict the remaining available habitat for slow lorises on the islands of Sumatra, Java, and Borneo. These estimates indicated that the Javan slow loris was the most threatened by habitat loss, followed by the Sunda slow loris from Sumatra. The Bornean slow loris was in a better situation since much of its range consists of low-risk areas. Both the Bengal slow loris and pygmy slow loris are found in more than 20 protected areas, although their populations are either low or insufficiently recorded.
In Indonesia, logging and the clearing of land for agriculture have triggered large forest fires, first in between 1982 and 1983 when burned in Kalimantan, and then again between 1997 and 1998 when burned in Kalimantan and Sumatra. These fires occurred within the native range of slow loris populations.
Although habitat loss has been significant throughout the range of the slow lorises, their decline is most closely associated with unsustainable trade, either for exotic pets or for traditional medicine. Slow lorises are abundant at the markets and are among the most commonly sold primates. Slow lorises are easy to catch because they do not leap from tree to tree, often freezing and covering their face when spotted. (For this reason, Indonesians call them malu malu or "shy one".) They are hunted not only by expert hunters, but are also easily caught by opportunist villagers because of the financial reward they bring at the markets.
Traditions and beliefs affecting conservation Traditional beliefs and uses for slow lorises vary, and many practices appear to have deep roots going back at least 300 years. Oral traditions suggest these practices go back even further. In the late 1800s and early 1900s, it was reported that the people from the interior of the island of Borneo believed that slow lorises were the gatekeepers for the heavens and that each person had a personal slow loris waiting for them in the afterlife. More often, however, slow lorises are used in traditional medicine or to ward off evil.
In the Mondulkiri Province of Cambodia, hunters believe that lorises can heal their own broken bones immediately after falling from a branch in order to climb back up the tree, and that slow lorises have medicinal powers because they require more than one hit with a stick to die. The hunters also believe that seeing a slow loris will bring bad luck on a hunting trip. In the province of North Sumatra, the slow loris is thought to bring good luck if it is buried under the foundation of a house. Similarly, villagers concerned about traffic safety might bury a slow loris under a road to prevent accidents. In Java, it is thought that putting a piece of its skull in a water jug would make a husband more docile and submissive, just like a slow loris in the daytime. Also, its body parts were used to place curses on enemies in North Sumatra. More recently, researchers have documented the belief that the consumption of loris meat was an aphrodisiac that improves "male power". The gall bladder of the Bengal slow loris has historically been used to make ink for tattoos by the village elders in Pursat and Koh Kong Provinces of Cambodia.
Legal protection The trade in slow lorises, whether as pets or for medicine, is illegal because every nation in which they occur naturally has laws protecting them. Cambodia lists them as protected, with penalties of one month in prison and fines of to in 2010 for anyone who catches, hunts, poisons, or transports them. In Indonesia, the slow loris trade has been illegal since 1973, when the Agriculture Ministry passed Decree No. 66. This regulation was clarified in 1999 with Government Regulation No. 7 ("Protection of Wild Flora and Fauna") and Act No. 5 ("Biodiversity Conservation"). Violators are subject to five years in prison and a fine of 100 million rupiah (~).