Only Sunda and Chinese pangolin (Pholidota) are naturally distributed in China

Actually, only two pangolin species occur naturally in China, namely the Chinese pangolin (Manis pentadactyla) and the Sunda pangolin (Manis javanica). The Sunda pangolin was found to occur naturally in Yunnan, China, but only with a narrow distribution in the Xishuangbanna and Pu'er City. The Indian pangolin (Manis crassicaudata) did not occur in China. The previous claim that this species is naturally distributed in China was found to originate from a mistake in the book “The Mammals of China and Mongolia” written by Allen in 1938. Pangolin is the common name for animals in the Family Pholidota, Mammalia, which consists of eight extant species. All pangolin species have been listed as critically endangered (CR), endangered (EN), or vulnerable (VU) species in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species (Challender et al. 2020). In June 2020, the Chinese government upgraded the Chinese pangolin (Manis pentadactyla Linnaeus, 1758) from a national second-class protected animal to a national first-class protected animal. In February 2021, the Sunda pangolin (Manis javanica Desmarest, 1822) and the Indian pangolin (Manis crassicaudata Geoffroy, 1803) were added to the list of national first-class protected animals. However, the number of species of pangolins naturally distributed in China varies in the literature: Some sources have recorded only one species, namely the Chinese pangolin (Nowak & Paradiso 1983; Sheng 1999), while most have recorded two species, namely the Chinese pangolin and Indian pangolin (Allen 1938; Zhang 1997; Wang 2003; Wu et al. 2005a; Hu & Hu 2017). A few sources have recorded the two species to be the Chinese pangolin and Sunda pangolin (Liu & Wu 2019; Wei et al. 2021). Some sources have recorded three species, namely the Chinese pangolin, Sunda pangolin, and Indian pangolin (Jiang et al. 2015). All literature sources have recorded the natural distribution of the Chinese pangolin in China, and its natural distribution in China is therefore undisputed. The main issue in past records is whether the Sunda pangolin and Indian pangolin are also naturally distributed in China. The number of pangolin species occurring in China urgently needs further investigation. The purpose of this study was to verify the validity of the natural distribution of all three pangolin species in China and to confirm how many pangolin species are naturally distributed in China by investigating pangolin specimens, reviewing the published literature, conducting interviews and a field survey, and using infrared camera traps. We traced the history of these three pangolin species in China in the published literature to determine how they were discovered in China and verified the validity of their distribution in China (Fig. 1). The literature consulted included various mammalian lists, mammalian monographs, mammalian faunas, scientific research reports, local chronicles, and journal articles from China and elsewhere. Also, we conducted inspection of collected specimens by selected 17 large specimen collection institutions (see Table S1, Supporting Information), each with a wide range of specimen sources and a rich variety of specimens. A total of 157 pangolin specimens (including skin and bones) were examined. Besides, in order to verify the natural distribution of the Sunda pangolin and Indian pangolin in China, we conducted a spot survey in the recorded distribution area (see Fig. S1, Supporting Information) of the Indian pangolin and Sunda pangolin in China (Allen 1938; Wu et al. 2005b). A total of 128 individuals from 36 institutions (see Tables S2,S3, Supporting Information) were interviewed, including hunters, nature reserve managers and technicians, forest rangers, and villagers. We assessed the pangolin identification skills of interviewees by letting them identify Chinese pangolins, Indian pangolins, and Sunda pangolins from photographs and explaining the different characteristics of each species. Seventy-nine of the interviewees had seen a pangolin before; among them, six were able to accurately identify the different pangolin species. We also conducted field surveys and infrared camera trap surveys in the literature recorded distribution areas of Indian pangolins and Sunda pangolins (see Fig. S1, Supporting Information) from July 2019 to July 2021. We conducted 14 field survey routes, with a total length of 26.86 km (see Table S4, Supporting Information), and set 70 infrared camera traps (see Table S5, Supporting Information). The first record of the natural distribution of this species in China was in the book “本草” (in Chinese) written in AD 480 (Wang et al. 2020). It has also been described in detail in many Chinese local fauna and other literature (Wu et al. 2005a, 2020). In the past 11 years (2010–2021), the authors discovered 197 live Chinese pangolins in the wild in the original distribution areas of this species in mainland China (Fig. 1). The natural distribution of the Chinese pangolin in China is undisputed. Chinese pangolins were historically distributed in a total of 19 provincial administration areas in China: Zhejiang, Guangdong, Guangxi, Hainan, Hubei, Hunan, Anhui, Fujian, Yunnan, Guizhou, Jiangxi, Chongqing, Sichuan, Jiangsu, Shanghai, Tibet, Henan, Hong Kong, and Taiwan (Wu et al. 2005a). However, the Chinese pangolin is currently exactly extant only in 12 provinces: Zhejiang, Guangdong, Guangxi, Hainan, Hunan, Anhui, Fujian, Yunnan, Guizhou, Jiangxi, Hong Kong, and Taiwan. There is a tendency toward the species being extant in Chongqing, Sichuan, and Hubei, while there is a tendency toward extirpation in Jiangsu and Henan, and the species has been extirpated in Shanghai. Tibet has a natural distribution of Chinese pangolins, but they are distributed in the region of Southern Tibet controlled by India (Menyu, Luoyu, and Zayu) (Fig. 1). Mangkang County and Zayu County (China-controlled region), which were previously thought to support the Chinese pangolin (Liu & Yin 1993), were never within the natural distribution area of this species. Based on an interview survey, Hu et al. (2014) stated that the Chinese pangolin is also naturally distributed in the Mount Everest National Nature Reserve in Tibet, China. The record of the Chinese pangolin is a new animal record in this nature reserve. However, a new animal record in this area based only on interview survey data is obviously unconvincing. The population of this species has been extremely reduced in most distribution areas, but there have been recent signs of recovery in some provinces. The frequency of wild pangolin discoveries in Jiangxi, Fujian, Zhejiang, Guangdong, Anhui, Hainan, and Taiwan is relatively high (Fig. 1a). There are few records of the distribution of the species in China. Anderson (1878) published the “Zoological results of the two expeditions to western Yunnan in 1868 and 1875,” in which it was confirmed that Bhamô to Kakhyens in western Yunnan (now in northern Myanmar, bordering Yunnan, China) is the distribution area of the Sunda pangolin. However, no records or specimens of the Sunda pangolin were discovered in China for more than 100 years after this report and no relevant literature was published. In 2002, Professor Shibao Wu from South China Normal University visited Kunming Natural History Museum of Zoology to inspect a pangolin specimen collection. He found a pangolin skin specimen with the collection number 006574 (Fig. 1b), which was morphologically distinct from other Chinese pangolins. He checked the specimens and confirmed that it was a Sunda pangolin rather than a Chinese pangolin. Based on this and other specimens, Professor Wu confirmed the Sunda pangolin as a new mammal record native to China and he wrote the paper, “A New Record of Mammalia in China—Manis javanica” (Wu et al. 2005b), which is the earliest record of the natural distribution of the Sunda pangolin in China. In October 2003, a researcher from the Kunming Institute of Zoology collected five live Sunda pangolin specimens in Menglian, Yunnan (Wu et al. 2005b). In April 2004, two researchers from the Kunming Institute of Zoology found four pangolin specimens in the Museum of Xishuangbanna National Nature Reserve. It was claimed that all four specimens were collected from the nature reserve, two of which were Sunda pangolins (Wu et al. 2005b). In July 2019, the authors went to the Xishuangbanna Reserve to verify the source of these two Sunda pangolin specimens (Fig. 1c,d). Senior engineer Qiaoyan Wang from the Xishuangbanna National Nature Reserve confirmed that all four pangolin specimens were collected in 1995–2000; three of the specimens were collected from Mengla within the nature reserve and one was collected from the nearby Mengyang Township. In July 2021, we conducted a spot survey in Menglian County and Pu'er City in Yunnan Province, where the distribution of the Sunda pangolin was recorded in the literature (Wu et al. 2005b). Fujin Liu, a 67-year-old Lisu nationality hunter in Lafu Village, Menglian County, Pu'er City, confirmed that the Sunda pangolin and Chinese pangolin were both distributed in the local area. Based on the above evidence, we believe that the Sunda pangolin is naturally distributed in a small area in the southern part of Yunnan, China, namely the area of Pu'er and Xishuangbanna bordering Myanmar (Fig. 1e). Many mammal lists and literature sources record their distribution in the Yunlong to Tengchong areas in western Yunnan, China, which borders Myanmar (Allen 1938; Zhang 1997; Wang 2003; Wu et al. 2005a; Jiang et al. 2015; Hu & Hu 2017). All of these lists and literature sources lack a description of the observation record, specimen collection information, morphological characteristics, and ecological data regarding the species. We also did not observe any living individuals or their tracks in the wild, and could not locate any Indian pangolin specimens collected in China. This raises concerns regarding the distribution of the Indian pangolin in Yunnan, China. Through a literature review, we found that the statement “Indian pangolins were naturally distributed in the area from Tengchong to Yunlong in western Yunnan, China,” originated in the book “The Mammals of China and Mongolia” written by Allen (1938). This book is the original literature source that first recorded the distribution of Indian pangolins in China. In the book, Allen wrote that a Chinese pangolin specimen from the Tengchong to Yunlong area in western Yunnan, China, described by Howell (1929) and later held in the American National Museum of Natural History, was actually an Indian pangolin. The stated distribution of Indian pangolins in China appeared in later literature, but originated from this book. However, after consulting Howell's (1929) original report “Mammals from China in the collections of the United States National Museum”, we found that this pangolin skin specimen from Tengchong to Yunlong in western Yunnan described in the article had 15 rows of scales over the back and 17 single flank scales along the tail edge (Howell 1929), which is consistent with the characteristics of the Chinese pangolin rather than the Indian pangolin. Howell (1929) also identified this specimen as a Chinese pangolin. Thus, the claim from Allen (1938) that the Chinese pangolin specimen described by Howell was an Indian pangolin is incorrect. Mahmood et al. (2020) also suggested that Allen (1938) incorrectly identified this Chinese pangolin specimen as an Indian pangolin. In the mammal list of the Gaoligongshan National Nature Reserve, only Chinese pangolins were recorded (Southwest Forestry College 1995). The IUCN Red List of Threatened Species (current edition) also states that Myanmar and the area of Tengchong to Yunlong in western Yunnan are not part of the distribution area of the Indian pangolin (Mahmood et al. 2019). During the spot survey in the Gaoligongshan National Nature Reserve, that is, the distribution range of the Indian pangolin in China according to Allen (1938), two local hunters who captured numerous pangolins in the local area confirmed to us that they had never captured Indian pangolins, and there were no Indian pangolins in the local area. In the museum of Gaoligongshan National Nature Reserve, only Chinese pangolin specimens were found. Three staff members of this nature reserve also confirmed to us that there were no Indian pangolins present in the Gaoligongshan National Nature Reserve. There is no evidence of the natural distribution of the Indian pangolin in China. We suggest that the statement from Allen (1938) that Indian pangolins are naturally distributed in Yunnan, China, is an error, and that the Indian pangolin is not naturally distributed in China. This study indicates only two pangolin species occur naturally in China, namely the Chinese pangolin and the Sunda pangolin. The Chinese pangolins in Tibet are only distributed in the region of Southern Tibet controlled by India (Menyu, Luoyu, and Zayu). Mangkang County, Zayu County (China-controlled region), and Mount Everest National Nature Reserve, which were previously thought to support the Chinese pangolin (Liu & Yin 1993; Hu et al. 2014), were not within the natural distribution area of this species. In the book “Wild Life Protection in Tibet,” Liu and Yin (1993) reported the distribution of Chinese pangolins in Tibet, including the regions of Zayu, Menyu, Luoyu, and Mangkang (Zayu means Zayu County, a part of the region controlled by India; Menyu, and Luoyu are located in Medog, Cona, and Longzi Counties, which are largely controlled by India). This book was the earliest literature source that recorded the natural distribution of Chinese pangolins in the Tibet and was later cited by many other authors (Tibet Forestry Survey and Planning Institute 2000; Tibet Autonomous Region Local History Compilation Committee 2005; Central South Forestry Investigation, Planning & Design Institute of the State Forestry Administration 2012). We conducted spot surveys in Cibagou National Nature Reserve (located in Zayu County), Zayu County, Medog County, Cona County, Longzi County (China-controlled region, where Zayu, Menyu, and Luoyu are located), and Mangkang County. Among the 113 interviewees, 20 were experienced hunters with a long history in the region and 43 were forest rangers who had patrolled the local forest for many years. None of them claimed to have seen a Chinese pangolin in the local area and some of them did not even recognize the animal from photographs. In addition, the environment conditions in Cona, Longzi, and Mangkang Counties are not suitable for the survival of this species due to the high altitude and low temperature. The “Checklist of the Mammals of Xizang (Tibet)” (Feng 1986) also contained no record of the Chinese pangolin. The Kunming Forestry Survey and Planning Institute has conducted animal resource surveys in the Cibagou Nature Reserve twice, but no pangolins have been found (Kunming Forestry Survey & Planning Institute 2017). We also interviewed the author of “Wild Life Protection in Tibet” (Liu & Yin 1993). He said that no Chinese pangolin specimens or burrows have been collected or found in Tibet. He speculated Tibet has the distribution of Chinese pangolin only from a suspected pangolin footprint and the distribution of pangolin prey. Obviously, it is unconvincing. The distribution of Chinese pangolin with only a narrow area in Menyu, Luoyu, and Zayu in Southern Tibet (India-controlled region). There are many literature sources describing the distribution of Chinese pangolins in the India-controlled region of Southern Tibet (Prater 1980; Choudhury 2002; Mishra et al. 2006; Chakravorty et al. 2011; Aisher 2016). This study was funded by the National Key Program of Research and Development, Ministry of Science and Technology (No. 2022YFF1301500) and the National Nature Science Foundation of China (No. 32070522), for which we are very grateful. Table S1 Specimen collection institutions (2001-2021). Table S2 Institutions interviewed for the Sunda pangolin. Table S3 Institutions interviewed for the Indian pangolin. Table S4 Details of field survey routes. Table S5 Number and location of infrared camera traps set in the survey area No. Figure S1 Region covered by the field survey for the Sunda pangolin and Indian pangolin. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

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