Pygmy Lorises were deemed a distinct genus (Xanthonycticebus) from other Slow Loris taxa (Nycticebus) based on have diverged approximately 11 million years ago, as well as other distinct traits including regularly giving birth to twins, having black naked ears, and a smaller skull length than Nycticebus (Nekaris and Nijman, 2022; Blair et al., 2023). Pygmy Lorises are relatively small (360-580 g); black nose; the fur on the crown patch of the head is orangish to light brown and is diffuse to ears with eye patches rather than sharply forked. Northern Pygmy Lorises are distinct from Southern Pygmy Lorises on the basis of a smaller skull length (50 mm or less), smaller mandible length (33 mm or less) resulting in a shorter muzzle; relatively fluffier pelage with longer hair (Blair et al., 2023). They also go through a more distinct seasonal coat colour and body mass change (Streicher, 2004).  There is no evidence of hybridization, either in the wild or in museum specimens, between N. bengalensis and X. pygmaeus from localities where the two are sympatric.

Xanthonycticebus intermedius is listed as Endangered as the species is suspected to have undergone a decline of more than 50% over the last three generations (24 years, given a generation length of 8 years). It is suspected that the population will continue to decline by at least 50% over the next 24 years. Population reduction is due primarily to hunting for pet trade, food, and ‘medicinal’ purposes in much of its distribution range, resulting in drastic declines that are reflected in higher prices in markets and reduced numbers available for sale. The species is increasingly rarely encountered in biodiversity assessments and is considered extremely rare and even extinct in its range in China. In addition, the species has also been impacted by and continues to be impacted by habitat loss from human settlements and agriculture, especially cashew plantations, corn and rice paddies.

This species is found in Mainland Southeast Asia east of the Mekong River in eastern Laos, southernmost China (southeastern Yunnan, historically north to Luchun), Northern Lao PDR as far west as Phôngsali, and Viet Nam north of the Hai Van Pass in Quang Nam Province (Blair et al. 2023). The western limit of distribution in Lao PDR is uncertain, but it appears to be absent in the extreme west of the Mekong plain.

In Viet Nam, researchers have concluded that wild populations are in major decline (Fitch-Snyder and Vu 2002, Streicher 2004). In 2002, in Phong Nha-Ke Bang National Park, 90 survey nights returned only seven sightings of this species; in Ben En National Park, only eight animals were encountered over ten night walks by four teams, each covering several kilometres per night. 2013-14 surveys in North Vietnam recorded 0.19 individuals/km and 0.4 individuals/km respectively (Blair, unpublished data). Surveys carried out in Central Viet Nam in 2015 at the boundary between the two Pygmy Loris species found low densities of Xanthonycticebus, with no animals observed in 20 km at Bach Ma National Park, and 0.19 ind./km at Son Tra Nature Reserve (Blair, unpublished data). In Ba Na-Nui Chua Nature Reserve, Danang, no Northern Pygmy Lorises were observed in surveys, though one trapped individual was recorded (Van Tuan et al. 2019). In Hue Saola Nature Reserve, Northern Pygmy Lorises were camera trapped at very low levels, a result that was attributed to heavy hunting (Nguyen et al. 2020).

In Lao PDR, Duckworth (1994) recorded only four individuals during a survey in Phou Xang He protected area (about 0.05-0.10 individuals/km). He further recorded the species in Nam Kading (0.06–0.13 individuals/km). It is possible that this species was under-recorded, however, as villagers claimed that this species was common throughout the area, but their accounts may also be historical (Duckworth, 1994; Evans, 2000). The species presence was also confirmed at Nakai-Nam Theun National Protected Area in Central Laos (Coudrat, pers. comm). The species is reported to be widespread in forested areas in Lao PDR, where exploitation of lorises is lower than in neighbouring Viet Nam, but this has not been confirmed with on-the-ground surveys.

In China, the species has been reported as extremely rare in Southeast Yunnan Province, with very few animals ever seen. Ma and Wang (1988) reported that their distribution is over Ma Guan, Ma Lipo, and He Kou County near the Sino-Vietnamese border. The species has been reported in Daweishan Nature Reserve of Pingbian (Xu et al. 2010). Only one individual was recorded in an area of more than 10 km² based on a camera trapping survey in Daweishan (Yu et al. 2013). 2015 surveys with local residents suggested that the Northern Pygmy Loris may occur in Xilongshan of Jinping, Huanglianshan of Lvchun, Gulinqing of Maguan, Laojunshan and Laoshan of Malipo, but no animals were seen despite extensive and continuing surveys, and researchers suggest some sightings result from individuals coming from the pet trade outside China and released back into China (Yu et al. 2013, Ni et al. 2020).

It is suspected that the species has undergone a >50% population decline in the last three generations (c. 21-24 years) and that it will continue to experience >50% population decline in the coming three generations. Historical population decline is suspected based on the information summarised above and elsewhere in this profile. For example, the species has not been found in China in systematic surveys over the last ten years. According to Global Forest Watch, since 2001, the species has lost 21% of habitat in its broadest geographic range. Combined with continual and heavy hunting, with the species being more sought after than other primate taxa for its use in over 100 traditional medicines, the species is considered to have lost 50% of its population. Future population declines are suspected on the basis that the threats facing this species continue.

This species has been sighted in a wide variety of habitats, including primary evergreen and semi-evergreen forest, forest on limestone, secondary and highly degraded habitats, and bamboo thickets (Ratajszczak 1998, Streicher 2004). It is found up to 1,500 m (MacKinnon and MacKinnon 1987).

Streicher (2004) found that released Northern Pygmy Loris had a diet comprised of insects (40%) and gums (30%), with the remainder comprising unidentified plant exudates. The species may also eat geckos, small arboreal mammals, eggs, and chicks (Ratajszczak 1998). Translocated Pygmy Lorises in Cuc Phuong had home range sizes of 25 ha for males and 9 ha for females (Poindexter et al., 2017). The Northern Pygmy Loris can enter multi-day hibernation and daily torpor, as well as go through extreme coat colour change and body mass changes (Ruf et al. 2015, Streicher 2004, Xiao et al. 2010). These data suggest that the species will be particularly vulnerable to climate change.

In captivity, Northern Pygmy Slow Lorises gave birth to twins (Streicher 2004). This species appears to be a seasonal breeder, giving birth in the winter months (Ratajszczak 1998).

In Viet Nam, the Northern Pygmy Loris is heavily exploited for traditional medicine as well as for the pet trade (Nekaris and Nijman 2007), including international trade, at levels that are not sustainable; many people also consume this species for food (Streicher 2005). Some hunting involves the use of elaborate traps, as well as snares. Ratajszczak (1998) mentioned that hundreds of individuals of this species were being traded in markets, a number that has declined dramatically suggesting a wild decline as well.

In Lao PDR threats in terms of use for medicines are lower. Habitat loss, due to agriculture (cashew plantations, corn, rice paddies and so forth), and human settlement, may be resulting in localized declines. Surveys are urgently needed to assess population numbers in Lao PDR.

In China, capture for traditional medicine and pet trade are still considered threats to the very limited remaining population. Ni et al. (2020) also argue that Pygmy Lorises are imported from other countries and may be released in China. More than 200 individuals were rescued from pet trade in China between 2000 and 2017, but it is not clear if these animals were imported to China as pets or if they were caught in China itself (Ni et al. 2018).

Pygmy Lorises (Xanthonycticebus spp.) are the most common loris species in international pet trade, and it is unclear from which countries these animals originate, and it is possible that some “breeders” try to breed the Southern and Northern species. Breeders in Japan expressed a greater desire for the Northern over the Southern species (Nekaris, unpublished data). Pygmy Lorises of unknown species have however, been introduced into non-native countries including Taiwan, Singapore and Thailand, causing potential problems for other non-native Slow Loris populations. Pygmy Slow Lorises are the most commonly seen primates on illegal Internet trade and in Japanese pet shops (Nekaris and Starr 2015, Musing et al. 2015). Their trade is also normalised across both popular and social media, potentially increasing the drive for pet trade of the species (Quarles et al. 2023).
 
Lack of law enforcement further threatens slow loris species across their range (Starr et al. 2010, Nijman et al. 2014).

The species is hunted for the pet trade, for traditional medicine, photo props, food, and various other purposes (Thach et al. 2018). The intensity of the trade has increased over the years, which is reflected in the decrease in volumes of the trade due to impacts on the wild population as well as increase in market value of the depleted stocks. Traders in Japan report that this species is preferred over the less “fluffy” and longer snouted X. pygmaeus (Blair et al., 2023). Indeed, this species is more prevalent in videos on YouTube (Nekaris et al. 2016).

In Viet Nam this species is protected at the highest possible level (Appendix IB, Decree 32, 2006); in China, it is listed as Class 1 protected (involving potentially severe penalties). In Lao PDR, it is protected by the Wildlife and Aquatic Law (2007) that classifies lorises under the ‘prohibited’ category (Nekaris and Starr 2015). The species has been transferred from Appendix II to Appendix I of CITES (Nekaris and Nijman 2007). There is a need for close monitoring of harvesting rates of this species, not only in Viet Nam, but also in China and Lao PDR where the species may be extinct, or where rates of offtake could increase in the future. 

Pygmy Lorises are represented in at least 50 captive collections, where they are a ‘red light’ species’ due to high inbreeding and low breeding potential (Fuller et al. 2014). Work is currently underway to understand which species are held in zoological collections and it is essential to know whether or not the captive population consists of Northern or Southern species or hybrids. The species is reported in at several protected areas, but these reports need to be ground-sourced with systematic surveys (Nekaris et al. 2008).

Researchers have attempted to bring attention to and mitigate the illegal online trade in Pygmy Lorises, which is particularly prevalent in Japan and Eastern Europe (Musing and Nekaris 2015). Ongoing campaigns combat the exploitation of Pygmy Lorises in illegal online videos (Nekaris et al. 2013, 2015).

This species has been the subject of many releases of confiscated individuals in Viet Nam, both monitored and unmonitored, often being unsuccessful (Streicher 2004). The Endangered Primate Rescue Centre in Cuc Phuong National Park, Ninh Binh Province, Vietnam, has been releasing Pygmy Lorises to the wild for more than two decades, but as two species were not recognised, it is possible that wild hybrids now exist, and it is urgent to check the status of released individuals. New strategies for release have been developed, however, with the number of successful releases on the increase; a standardised best practice for release is beginning to be recognised (Kenyon et al. 2014).