The snow leopard Panthera uncia is categorized as Endangered on the IUCN Red List (Jackson et al., Reference Jackson, Mallon, McCarthy, Chundawat and Habib2008), and China is the most important country for conservation of the species because it has the most potential habitat and the largest population of snow leopards (Snow Leopard Network, 2014; Alexander et al., Reference Alexander, Zhang, Shi and Riordan2016a). The north-west of Yunnan province in south-west China is a biodiversity hotspot at the edge of the snow leopard's range (Mittermeier et al., Reference Mittermeier, Gil, Hoffmann, Pilgrim, Brooks, Lamoreux and da Fonseca2004; McCarthy et al., Reference McCarthy, Mallon, Sanderson, Zahler, Fisher, McCarthy and Mallon2016). There is much uncertainty regarding the status of snow leopards in this area, and Riordan et al. (Reference Riordan, Cushman, Mallon, Shi and Hughes2016) expressed the need for more snow leopard surveys there to assess the validity of distribution maps. During 1950–1999, snow leopards were detected at three locations in north-west Yunnan (Alexander et al., Reference Alexander, Zhang, Shi and Riordan2016a). However, the IUCN Red List records the species as regionally extinct in Yunnan (Jackson et al., Reference Jackson, Mallon, McCarthy, Chundawat and Habib2008), although Smith & Xie (Reference Smith and Xie2008) note that snow leopards are present there. Here we present data from several areas in north-west Yunnan to help clarify the status of snow leopards in this province. Three major rivers, the Yangtze, Mekong and Salween, flow down from the Tibetan plateau into north-west Yunnan, and then run approximately parallel for > 300 km, within a span of c. 100 km, separated by the Hengduan–Shan mountain ranges, with peaks up to 6,740 m. The rivers have created a complex topography, with diverse habitats, and consequently this area is a biodiversity hotspot (Mittermeier et al., Reference Mittermeier, Gil, Hoffmann, Pilgrim, Brooks, Lamoreux and da Fonseca2004) and is designated the Three Parallel Rivers UNESCO World Heritage site (UNESCO, 2010; Fig. 1).

Fig. 1 Location of the Three Parallel Rivers World Heritage Site and the four study sites in north-west Yunnan, China, where interviews and camera-trap surveys were conducted to investigate the status of the snow leopard Panthera uncia.

Interviews and camera trapping have been useful in determining the status of snow leopards and other wildlife (e.g. Taubmann et al., Reference Taubmann, Sharma, Uulu, Hines and Mishra2016; Chen et al., Reference Chen, Gao, Wang, Pu, Lhaba and Hu2017). We conducted semi-structured interviews, using pictures to distinguish between similar species. In autumn 2012 we conducted interviews with herders and nature reserve officials at two study sites between the Yangtze and Mekong Rivers: 23 herders and two officials in the northern area of Baimaxueshan Nature Reserve near Yeri village, and four herders in Guji valley adjacent to Baimaxueshan (Fig. 1). In spring 2013 we conducted interviews with local herders at two study sites east of the Yangtze River: five herders near Langdu village and four herders near Balagezong Nature Reserve (Fig. 1). We also deployed heat/motion-sensing camera traps (Bushnell) near Langdu, Yeri and Guji. We set cameras along wildlife trails or areas snow leopards might use, such as along ridges and mountain passes, and we set cameras singly to maximize the area covered. Near Langdu we set six cameras during June–December 2013 at 4,600–4,800 m altitude. At Baimaxueshan near Yeri we set 15 cameras during December 2012–September 2014 in 41 unique locations at 2,700–5,100 m altitude, and at Guji we set three cameras during September 2013–April 2014 at 4,750–4,929 m altitude. Near Yeri we set cameras in four locations 10–19 km apart. Within each of these locations the mean distance between neighbouring cameras was 420 m. At Langdu the mean distance between cameras was 920 m, and at Guji the mean distance between cameras was 440 m.

At all sites the herders and officials interviewed indicated that snow leopards were present but that there was no predation of livestock by snow leopards and no evidence of poaching of snow leopards. The cameras were deployed for 879 camera-days at Langdu, 4,824 camera-days at Baimaxueshan, and 597 camera-days in the Guji valley. We did not record any photographs of snow leopards so it is likely that if snow leopards are present they are rare. However, we did record many images of potential snow leopard prey. We recorded at least 496 blue sheep Pseudois nayaur in nine groups of 15–126 individuals, 264 images of the Chinese goral Naemorhedus griseus, 16 images of alpine musk deer Moschus chrysogaster, three of Chinese serow Capricornis milneedwardsii, five of tufted deer Elaphodus cephalophus and one wild boar Sus scrofa. We considered consecutive photographs of the same species to be independent when there was at least a 1-hour interval between the photographs (Rovero & Marshall, Reference Rovero and Marshall2009).

At Baimaxueshan three herders and the two officials claimed common leopards Panthera pardus were also present, and we recorded 17 images of common leopards at 3,000–4,500 m altitude. It was not possible to determine how many individuals were photographed because the images were not of sufficient quality to confidently distinguish individuals. Common leopards were poached > 20 years ago, according to herders, who showed several common leopard skins, but there were no reports of recent poaching, and several purported common leopard skins for sale in local tourist shops transpired to be fake. Common leopards are considered to be potential predators of Yunnan snub-nosed monkeys Rhinopithecus bieti, which occur at 3,900–4,300 m at Baimaxueshan, but there are no records of predation (Kirkpatrick et al., Reference Kirkpatrick, Long, Zhong and Xiao1998).

Conservation efforts for snow leopards may benefit other carnivores (Alexander et al., Reference Alexander, Cusack, Chen, Shi and Riordan2016b). Laguardia et al. (Reference Laguardia, Kamler, Li, Zhang, Zhou and Shi2017) reported no records of common leopards in western China at > 4,000 m altitude, but our study shows the need to survey adequately at high altitudes to obtain robust data for both common and snow leopards, especially as common leopards may be rarer than previously thought in China (Laguardia et al., Reference Laguardia, Kamler, Li, Zhang, Zhou and Shi2017). The abundance of potential prey at our study sites suggests that there is much potential habitat available for both leopard species. In the central Himalaya both species eat similar prey items, and common leopards have shown wide adaptability to diverse habitats at elevations up to 5,000 m (Lovari et al., Reference Lovari, Minder, Ferretti, Mucci, Randi and Pellizzi2013a,Reference Lovari, Ventimiglia and Minderb). Climate change has led to the upward movement of forests and the increase of common leopard habitat at the expense of snow leopard habitat (Lovari et al., Reference Lovari, Ventimiglia and Minder2013b), and snow leopards may adjust their ranging to avoid competition with common leopards (Ferretti & Lovari, Reference Ferretti and Lovari2016). In several areas of China (Eastern Tibet, Mount Gonggashan, Sichuan and Sanjiangyuan Reserve, Qinghai) camera traps have recorded both snow leopards and common leopards at the same location (Wen, Reference Wen2016; Yang, Reference Yang2016; JiaWu Xiong & Tong Zhang, pers. comm.). The Baimaxueshan Management Office is planning long-term camera trapping in alpine and remote areas in the reserve to monitor snow leopards and common leopards and their prey. The data presented here will be valuable for comparison with the findings of this work. More study is also needed in other parts of Yunnan and south-west China to elucidate resource overlap and the potential for competition between the leopard species. This work should include camera trapping and/or genetic analyses (Janečka et al., Reference Janečka, Jackson, Yuquang, Diqiang, Munkhtsog, Buckley-Beason and Murphy2008). Our findings confirm that caution is justified when interpreting interview data on the presence of species (Caruso et al., Reference Caruso, Vidal, Guerisoli and Lucherini2017).