Southern extension of raccoon dog Nyctereutes procyonoides (Mammalia: Carnivora: Canidae) range in Vietnam with comments on its conservation status in the country

Although the raccoon dog Nyctereutes procyonoides has a wide global distribution, little is known about its population in Vietnam. The species is considered rare in Vietnam, and few records have been published since 2004, although it is worth noting that all of these records were wildlife trade observations or anecdotal reports. Here, we report raccoon dogs recorded in the illegal wildlife trade via Facebook monitoring from January to December 2020, rescued animals documented in the Nghe An province caught by a hunter in August 2020, and camera trap records of the species detected in Pu Mat National Park in May and July 2021. Our camera trap recordings provide evidence of a southern range extension for this species in Vietnam and represent the first documented occurrence of raccoon dogs captured in situ by camera traps within the country.


Introduction
The raccoon dog Nyctereutes procyonoides (Gray 1834) belongs to the Canidae family and is native to and has a wide range in Asia (Russia, Mongolia, Korean Peninsula, Japan, China, and Vietnam); it is considered an introduced species in Northern Europe (Hong et al. 2018;Lavrov 1971) and expanded its range to Central Europe (Drygala et al. 2016). Raccoon dogs are omnivorous; their diet varies from frogs, reptiles, birds, rodents, carrion, invertebrates, vegetables, and fruits (Hirasawa et al. 2006;Kauhala et al. 1998;Kauhala and Auniola 2001). The species is a habitat generalist and can be found in gardens, open woodland, forested streams or river valleys, and areas surrounding lakes where thick underbrush, marshes, or reed beds provide dense cover (Hirasawa et al. 2006;Kauhala and Saeki 2016;Kauhala and Auttila 2010). Six subspecies of N. procyonoides have been described, including N. p. ussuriensis in Russia, northeastern China, and Eurasia; N. p. procyonoides in southern China and north Vietnam; N. p. albus and N. p Japan; N. p. orestes in China; and N. p. koreensis in the Korean Peninsula (Hong et al. 2018). Due to its wide range and steady population throughout most of its range, the species is listed as Least Concern by the IUCN Red List of Threatened Species (Kauhala and Saeki 2016). Although the raccoon dog is nonnative to Europe, the species is quite well studied in terms of habitat use, dispersal, diet, social organization, genetic characterization, zoonotic diseases, and invasion impacts on native European species (Drygala 2009;Duscher et al. 2017;Kauhala and Auniola 2001;Kauhala and Kowalczyk 2011;Paulauskas et al. 2016;Süld et al 2014;Sutor et al 2014). However, studies in Asia have focused mostly on genetics and distribution -namely, in Japan, Korea, Taiwan, and China (Asahara et al 2015;Hong et al 2018;Kang et al 2018;Kim et al 2013), with few studies existing for the species in Vietnam (Hoffmann et al 2019). This paper presents the first confirmed wild record of N. procyonoides in Vietnam through the use of camera traps, with supplementary record from rescued animals, and monitoring of illegal wildlife trade on Facebook. The included records of distribution and threats provided can be used in reassessing the species' national status.

Methods
Three types of data collection methods were used to obtain records on raccoon dogs, which included:

Camera-trapping
Two separate camera-trapping instances recorded raccoon dogs in the botanic garden of Pu Mat National Park. The first, which was set on video capture (30 May 2021), showed three raccoon dogs (two adults and one sub-adult) crossing the botanic garden under a bird box which the camera was monitoring (Fig. 1A). This location represents a southern extension to the species' known range in Vietnam: it is ca. 300 km southwest from the nearest known population in Huu Lien Nature Reserve, Lang Son Province, northeast Vietnam (see Kim et al. 2013). The same group of three or possibly another (we were unable to distinguish individuals) was detected at the same location with another camera in July 2021, this time with a focus on terrestrial species in the area rather than the bird box.

Local hunter interview
Three raccoon dogs were caught by a local hunter in the Lam River mudflats in Ha Nam Village, Dinh Son Commune, Anh Son District, Nghe An Province (coordinate, 19°02′ N 104°55′ E, WGS 84; elevation, 25 m a.s.l) using a large fishing dip net with a long pole at night after collecting sleeping birds on Lam river's bank. The first day (25th August 2020), he caught one individual raccoon dog ( Fig. 1C) by chance and saw another one that had escaped. The three following nights, he tracked the escaped raccoon dogs and captured two other individuals. He then kept the three raccoon dogs in a steel cage and displayed them in his yard. According to the hunter, that was the first time he had seen the animal in the area even though he had lived here for over 50 years. One of his neighbors photographed the animal he caught and posted on his Facebook to ask for species identification, since the hunter did not know which species he had caught. Later, one of the district police noticed and convinced him to transfer the animals to the Wildlife Rescue Centre at Pu Mat NP. The confiscated raccoon dogs were given individual health assessments and were released in Pu Mat NP in September 2021.

Social media monitoring
During our Facebook monitoring efforts from January to December 2020, we recorded 31 individuals of raccoon dogs advertised for sale (Table 1). In several groups, dealers were selling hunted raccoon dogs or showing evidence that they were hunting the species: "Hội săn bẫy Chim Thú Việt Nam" (group for hunting and trapping birds and mammals in Vietnam), "Hội đam mê săn bẫy toàn quốc" (group for nationwide wildlife hunting passionate), "Hội đánh bẫy chim thú 3 miền" (group for trapping birds and mammals in three large regions of Vietnam), and other posts that were among those suggested by the Facebook algorithm on the personal Facebook newsfeed of M.T. Trinh, T.V. Pham, and T.V. Nguyen after joining several hunting and trade groups. The group recorded to sell raccoon dogs most frequently was "Hội săn bẫy Chim Thú Việt Nam" (group for hunting and trapping birds and mammals in Vietnam), accounting for 53.3% (n = 30). We also checked the Facebook profiles of people who posted photos and videos of raccoon dogs for sale on Facebook groups in an attempt to determine their provincial locations. Approximately, 43.3% of traders were concentrated in northern provinces, while the remaining trades occurred in smaller amounts throughout central and southern Vietnam (Fig. 2). Through the survey, we contacted the sellers via Facebook messenger using a fake account to find out whether the raccoon dogs were wild caught and to get as much detail on the capture locality of the animals as we could. Only four of 30 sellers we contacted answered, all of whom replied that their raccoon dogs were wild caught. Two sellers confirmed that they obtained the raccoon dogs from local people in Binh Lieu and Bai Chay districts of Quang Ninh Province, northeast Vietnam. One seller claimed he received the raccoon dog from Lao Cai Province, northwest Vietnam (the district was not mentioned). Notably, one seller claimed that he captured raccoon dogs from a forest in Anh Son District, Nghe An Province near Pu Mat NP, which provides further evidence of the presence of raccoon dogs in forests surrounding the national park. The price for raccoon dogs ranged from 1.6 to 2.2 million VND (approximately $70-97 USD) per individual. The price is slightly different in Hoffmann et al. (2019) which stated that live cubs were sold for 2,500,000 VND (~ USD110).

Discussion
The botanical garden within Pu Mat NP headquarters where the raccoon dogs were recorded on camera traps is comprised of various native trees characteristic of a mixed dipterocarp forest (e.g., Dipterocarpus ssp., Acacia spp., Hopea odorata). The botanical garden is surrounded by limestone and evergreen forest; limestone forests with caves might be used as shelter sites for raccoon dogs (Hoffmann et al 2019). Agricultural land (mostly rice paddies and corn fields) and residential areas are approximately 300 m away from where the raccoon dogs were detected. The habitat where the hunter captured three other raccoon dogs was situated in a grassland area (Fig. 1D) on the side of Lam River, surrounded by corn and peanut fields and a nearby village. It is unclear why a hunter who has decades of experience has never observed raccoon dogs in Nghe An before until recently. We checked into a list of wildlife farms from the Nghe An Forest Protection Department (FPD), and there are no farms for this species, so it is unlikely the observations were a result of escaped animals. Furthermore, over 70,000 camera trap nights in Pu Mat National Park between 2018 and 2021 have not detected raccoon dog (SVW, Leibniz-IZW, Pu Mat NP, unpublished data). However, all of these camera traps were in evergreen forest, the main habitat type of the national park, with little to no survey effort in more open or anthropogenically disturbed habitat types. A very limited, non-targeted camera-trapping effort in the national park's botanical garden has produced the only confirmed record for this species in Pu Mat National Park, despite a relatively long history of faunal surveys and previous camera-trapping efforts (Oanh et al. 2004;Nghia et al. 2020). This is probably due to detectability issues linked to the species' preference for more open/ disturbed habitat types and a camera-trapping bias towards the park's montane, evergreen forests (Hirasawa et al. 2006).
According to our in situ camera trap detections and encounters by the hunter, raccoon dogs' preference for disturbed habitat types is similar to previous findings on the species from Hirasawa et al. (2006). Hoffmann et al. (2019) stated that populations of raccoon dog were once widely distributed in the northeastern extents of Vietnam but have clearly declined, and now their status is uncertain. Since the species may prefer disturbed or more open habitat spaced which are often also occupied by humans, where threat of hunting is extremely high, the remaining abundance of raccoon dogs in Vietnam is unknown and potentially experiencing the same decline as previously known populations.
Although raccoon dogs are found across in Asia and Europe and regularly observed in some countries, species records are rare in Vietnam. In previous years, there were a few observations of raccoon dogs recorded in the northeast: two individuals observed in a village of Tuyen Quang Province in 2004 (Le Trong Trai pers. obs. 2004) and eight individuals used for molecular analysis in Kim et al. (2013) that were obtained from local hunters in Huu Lien Nature Reserve, Lang Son Province. The species has previously been recorded in ~ 16 provinces of Northern Vietnam, but all previous records failed to provide any concrete or verifiable supporting evidence (see Hoffmann et al 2019).
In terms of conservation status, hunting and trade as pets and wild meat are visible threats to raccoon dogs in Vietnam. Illegal wildlife trade on Facebook still persists in Vietnam since the development of social network (see Pham et al. 2019) even with recent crackdowns (Aung 2020). Therefore, SVW proposed elevated species protections under decree 06/2019/ND-CP in early 2021. As a result, the species has been amended into the new decree update 84/2021/ND-CP under group IIB, with fines for illegal hunting, transporting, or trading per individual, thus providing better protection of raccoon dogs in Vietnam.
In conclusion, traders from Facebook offer to sell wildlife from locations in which they may not have originated, so trade locations may be an unreliable representation of true range of raccoon dogs in Vietnam. Data on viable protected areas to release individuals confiscated from the illegal wildlife trade is still needed to effectively translocate them and increase probability of survival. Further study is required to verify the species' range in the country; especially in Nghe An and why the species is suddenly appearing after decades of being undetected. Whether our in situ observations were a product of his climate-driven migration, escaped animals from trade, Hai Phong 2 2019-05-22 Not stated 1 2020-01-11 Hung Yen 1 2020-02-04 Hung Yen 1 2020-02-04 Quang Binh 1 2020-02-11 Not stated 1 2020-02-19 Thanh Hoa 1 2020-02-22 Nghe An 1 2020-03-15 Thanh Hoa 1 2020-03-18 Bac Ninh 1 2020-04-04 Not stated 1 2020-04-18 Thanh Hoa 1 2020-05-10 Ho Chi Minh City 1 2020-05-11 Not stated 1 2020-05-11 Dak Lak 1 2020-06-18 Not stated 1 2020-07-10 Hai Phong 1 2020-08-06 Ha Giang 1 2020-08-08 Binh Duong 1 2020-08-08 Not stated 1 2020-08-08 Binh Duong 1 2020-09-29 Quang Ninh 1 2020-09-30 Lao Cai 1 2020-10-09 Thua Thien-Hue 1 or simply lack of sampling in their preferred habitats is still to be determined. Fig. 2 Choropleth map of the raccoon dog trade records detected during online trade monitoring and with reference to the location of camera trap records in Pu Mat National Park (star). Recorded province does not equate to species presence in that province given the difficulties of confirming provenance using wildlife trade observations