Formerly this species was placed in the genus Uncia but it is now assigned to Panthera according to genetic analysis (Johnson et al. 2006). It is most closely related to the tiger Panthera tigris, having diverged over two million years ago (O'Brien and Johnson 2007). Two subspecies have been named based on minor morphological differences (Medvedev 2000) but have not been confirmed by genetic analysis.

The Snow Leopard is assessed as Vulnerable because the global population is estimated to number more than 2,500 but fewer than 10,000 mature individuals, and there is an estimated and projected decline of at least 10% over 22.62 years (3 generations). There have been five attempts to compile national estimates, of varying data quality, to determine global Snow Leopard global population size. Two sets contain estimates largely dating prior to 2003: 4,080-6,500 (McCarthy and Chapron 2003) and 3,920-6,390 (Snow Leopard Working Secretariat 2013). Two sets date from 2008-2010: 4,500-7,500 (Jackson et al. 2010) and 4,678 to 8,745 (a compilation of individual population estimates for prime habitat covering about 1/3 of likely extant range developed at an expert mapping workshop in 2008 but not available until 2016: McCarthy et al. 2016). The most recent set of national estimates comes from country chapters in the comprehensive book Snow Leopards: 7,463 to 7,980 (McCarthy and Mallon 2016, Thinley et al. 2016: Table 1 in the Supporting Information). While all these sets of estimates exclude dependent cubs, a population modelling exercise was carried out in 2015 to exclude young adults which may not be capable of breeding (Appendix 2 in the Supporting Information). Model outputs for nine different scenarios were applied to the most conservative possible global population estimate available at the time (4,000), resulting in a number of mature individuals between 2,710 and 3,386. The number of mature individuals would be roughly double if applied to the upper bounds of the more recent estimates published in 2016.

There is virtually no substantiated documentation of population trends over appropriate time scales; Snow Leopard numbers are reportedly stable or modestly increasing in some areas, but are likely to be declining in others, including recent localized extinctions which may have occurred in some areas of the former Soviet Union. A decline of at least 10% over the next 3 generations (22.62 years) is estimated given the growing threat related to increasing livestock numbers in some countries or emerging threats like intensified road construction and mineral extraction. Although poaching appears to have declined since the late 1990s, Nowell et al. (2016) estimated that 221-450 Snow Leopards were poached annually since 2008 (based on extrapolation of cases known to over 40 surveyed experts); these were attributed to retaliation for actual or perceived livestock depredation, but this supposition is not substantiated by hard evidence. With the average rate of poaching detection estimated by experts at less than 38%, these numbers could be substantially higher. If these poaching estimates are anywhere near accurate, this suggests that roughly 2-10% of the population could be poached annually. While a direct relationship between offtake and a population decline is not clear, even at the magnitude reported by Nowell et al. 2016, it adds to the plausibility of a 10% decline over 3 generations (22.62 years).

Approach to Uncertainty
The IUCN Red List Criteria are designed to incorporate the use of inference, suspicion and projection, to allow taxa to be assessed in the absence of detailed and complete data, which are rarely available across the entire range of a taxon; the absence of high-quality data should not deter attempts at applying the criteria (IUCN Standards and Petitions Subcommittee 2016). Throughout this assessment, we have attempted to show the degree to which we have dealt with uncertainty stemming from the paucity of data for this elusive and secretive species. To ensure this assessment is both “precautionary and credible," as specified by IUCN (2012), a range of values as well as best estimates were considered for the critical parameters, including those used in modelling the number of 'mature individuals' (MI) in the population. Specifically, the model dealt with uncertainty by including a variety of scenarios with cats maturing between 2 to 4 years of age, and then applied the resultant MI percent to the lowest published population estimate which, contrary to convention, included dependent yearlings (Appendix 2 in the Supporting Information). Here, even the very lowest bound of the estimated range of mature individuals did not fall within the threshold for the Endangered category.

It is acknowledged that precise and robust estimates of Snow Leopard density are difficult to obtain, are available for only a limited proportion of the global range, and represent small study sites selected for their suitability for the species. Because extrapolation to larger areas or even range-wide would be tenuous, we have avoided doing so in all cases. Estimates of Snow Leopard population size based on rigorous study design and survey methodology are sparse. The national population estimates cited here are considered to be the best available, following advice in the Red List Guidelines: “The plausible range may be established using.….. the opinion of a single expert, or the consensus view of a group of experts” (IUCN Standards and Petitions Subcommittee 2016).

There is also a lack of hard data on overall population trends, which hinders estimates of the magnitude of any decline which rely on fragmentary evidence and are therefore largely speculative. Nonetheless, the evidence considered does not suggest that the situation has deteriorated since 2008, which would be needed to justify an Endangered listing under criterion C1.

Reasons for Change in IUCN Red List Status
The previous assessment in 2008 (Endangered C1) was based on <2,500 mature individuals and an estimated decline of 20% over 16 years (two generations). However, in that assessment, effective population size (Ne) was incorrectly used as a surrogate for ‘mature individuals’ and produces a lower figure (50% of the adult population of 4,080). Therefore, the species should have been listed as Vulnerable in 2008.

Moreover, given the apparent limits to dispersal (Riordan et al. 2015), it is questionable whether such a small number of individuals capable of breeding (and therefore fewer actually breeding) is demographically viable over such an extensive range. Recent survey information indicates that Snow Leopard densities in several areas are higher than previously believed, implying that the overall population size is also likely to be larger than the minimum estimates (Jackson et al. 2010, SLSS 2014, McCarthy and Mallon 2016). The revised estimate of the number of mature individuals addressed the earlier mistake, in combination with new information, and the change from EN to VU is therefore a non-genuine change.

The estimated 20% decline over 16 years in 2008 included a documented upsurge in poaching for skins and body parts in the countries of Central Asia, following the break-up of the Soviet Union around 1991. While this threat has since subsided, it is unlikely to have completely disappeared. The other traditional threats still exist, alongside emerging potential threats such as mining and other infrastructure development (roads, railroads, hydro-dams, etc.), some of which will have intensified in recent years (summaries in Snow Leopard Network 2014, McCarthy and Mallon 2016).

There have also been very significant investments in conservation measures to reduce threats or to mitigate their effects. These include: establishment of new protected areas in Snow Leopard range; more effective anti-poaching measures; training and capacity-building of range country conservation professionals; a number of independent initiatives to reduce conflict with herders (e.g., strengthening livestock corrals, vaccination, handicrafts and alternative livelihoods, grazing set-asides); community engagement programmes; the illegalization of guns in China since 1989; and education programmes to raise awareness of the Snow Leopard and its habitat (see the Conservation Measures section for more details and examples). The Rangewide Priority Setting workshop in Beijing in 2008 (Sanderson et al. 2016), the Global Snow Leopard and Ecosystem Protection Program (Snow Leopard Working Secretariat 2013) and the revised version of the Snow Leopard Survival Strategy (Snow Leopard Network 2014) have all enhanced the global strategic framework.

Although the Snow Leopard undoubtedly is still threatened, the measures listed above are collectively considered to have contributed to improving the overall conservation situation for Snow Leopards since 2008. The generation length of 8 years used in 2008 has been revised to 7.54 years following Pacifici et al. (2013). There is no current evidence to support a decline of 20% over such a short period of 15.08 years, as needed to support a listing as Endangered, and which would represent a steeper decline and therefore a deterioration in the situation since 2008. However, in view of the existing and emerging threats, a decline of 10% or more over 22.62 years (three generations) is considered plausible (starting in 2014). This change in the estimated rate of decline is the result of conservation actions taken, so potentially could qualify as genuine change and on this basis IUCN's 5-year waiting period would apply, dated from the first draft of this assessment (June 2014). However, since the EN category in 2008 was incorrect, the species should have been listed as VU in 2008, the change in category is therefore non-genuine.

The range of the Snow Leopard extends from the Himalaya in the south, across the Qinghai-Tibet Plateau and the mountains of Central Asia to the mountains of southern Siberia in the north. It occurs in the Altai, Sayan, Tien Shan, Kunlun, Pamir, Hindu Kush, Karakoram, and outer Himalayan ranges and in smaller isolated mountains in the Gobi region. It occurs in 12 countries: Afghanistan, Bhutan, China, India, Kazakhstan, Kyrgyzstan, Mongolia, Nepal, Pakistan, Russia, Tajikistan and Uzbekistan. A small area of potential range occurs in northern Myanmar but recent Snow Leopard presence has not been confirmed. The area of occupied range was recently estimated to be about 2.8 million km² (McCarthy et al. 2016).

There are no robust estimates of Snow Leopard global population size and the various figures available are best regarded as guesses: 4,080-6,500 (McCarthy and Chapron 2003); 4,500-7,500 (Jackson et al. 2010), and 3,920-6,390 (Snow Leopard Working Secretariat 2013). There are several difficulties to overcome in making reliable estimates of Snow Leopard population size (Snow Leopard Network 2014), namely this species’ secretive nature, generally low density, sparse (or sporadic) distribution and remote terrain contributing to generally low detection rates and small sample sizes that in turn may make extrapolation problematic. Until recently, most studies were conducted over rather small areas, sometimes smaller than the home range of a single Snow Leopard, rendering the information inadequate to make population and density inferences over larger areas (Appendix 1 in Snow Leopard Network 2014). Furthermore, not all studies report the size of the surveyed area, thus precluding generation of density estimates. These limitations are starting to be addressed, for example through the adoption of more robust methods, such as spatially-explicit recapture models from camera data (e.g., Shrestha et al. 2013, Thinley et al. 2014, Alexander et al. 2015). Additionally, recently published information includes relatively rigorous surveys conducted over larger areas (see below).

Snow Leopards are known to breed at 2 or 3 years of age (Leif Blomqvist, International Snow Leopard Studbook Keeper, Helsinki Zoo, pers. comm., Jay Tetzloff, US Association of Zoos and Aquariums Snow Leopard Species Survival Plan Coordinator, pers. comm., McCarthy and Chapron 2003). Field observations are consistent with Snow Leopards breeding at 2 or 3 years of age. Of two known-age females in a long-term radio-telemetry study of Snow Leopards in Mongolia, one gave birth at the age of 3 years and the other at age 3 or 4 years (O. Johansson, pers. comm. and Panthera/Snow Leopard Trust unpublished data). Since breeding occurs in February/March and birth occurs in May/June, this means that one female definitely bred at age 2 years and the second bred when either 2 or 3 years old. Two other females of estimated age in the same study likely gave birth when 3-4 years old, again indicating successful breeding at 2-3 years old. Sexual maturity and breeding at 2-3 years old appears to be consistent across a range of large wild felids (Berry et al. 1997, Hunter 1998, Kelly et al. 1998, Balme et al. 2012, Hunter et al. 2013, Miller 2013, Miller and Funston 2014).

The IUCN Red List guidelines (IUCN Standards and Petitions Subcommittee 2016) define 'mature individuals' as individuals known, estimated or inferred to be capable of reproduction. The guidelines also state that age of first reproduction in the wild may be later than the age at which an individual is biologically capable of breeding. Hence, mature individuals in the Red List context are those capable of breeding, not just those actually breeding in any given year. Snow Leopards are capable of breeding beginning at 2 years of age and thus meet the IUCN definition of mature individuals, even if they do not actually start to breed this young.

Estimating the percent of mature individuals (≥ 2 years of age) in the wild Snow Leopard population has been historically difficult, but with the extensive application of camera trapping new information is available. In 21 camera trapping studies conducted in 6 countries between 2003 and 2014 and comprising more than 29,165 trap-nights, a mean of 82.3% of Snow Leopards captured in photos were independent animals (Appendix 1 in the Supporting Information). Snow Leopards become independent at between 18 and 26 months old, hence, a small percent of independent cats in camera trap photos may not yet have reached the mature age class (2-year olds).

With few exceptions, published felid population estimates do not include dependent cubs. Camera-trapping derived density estimates are an example where exclusion of cubs applies. The global population estimate of 4,080-6,590 Snow Leopards (McCarthy and Chapron 2003) only includes mature individuals. Similarly, the 2008 Red List assessment (Jackson et al. 2008) for Snow Leopard states that the population estimate is for adults only and the authors calculate effective population size (2,040) as 50% of the estimated total number of adults (4,080), citing Nowell et al. (2007). Hence, for the purposes of estimating the percent of mature individuals, published Snow Leopard population estimates should be considered to be comprised of adults only.

Population modelling can be used to estimate the percent of individuals in each age class. McCarthy et al. 2015 (Appendix 2 in supplementary material) employed a stochastic age-structured population model to produce a suite of stable stage population matrices. Vital rate input variables included the age at which Snow Leopards become capable of reproduction (mature), and the percentage of each age class that actually bred. The proportion of yearlings in the population estimate varied in the model from 0% to 50%. The model was run using nine scenarios of various combinations of vital rates and percentages of yearlings in the population. The lowest percentage of mature individuals (MI) was obtained when 2-year old maturity rates were lowest (25%), actual breeding did not begin until age 3, and the proportion of cubs in the population estimate was highest (50%). Yet even in that most precautionary scenario a mean MI of 67.7% (s.d. = 2.07) was obtained. Applying that MI percent to the most conservative global population estimate of 4,000 individuals, yields 2,710 (s.d. = 83) mature individuals. Model outputs for all nine scenarios when applied to this minimum population of 4,000 ranged from 2,710 to 3,386 MI. In no case did MI fall below the threshold required for an Endangered designation for the species.

A population of < 2,500 mature individuals distributed across 1,776,000 km² (taking a relatively conservative estimate of global range size from Snow Leopard Working Secretariat 2013) or a maximum of 3,300,000 km² (Snow Leopard Network 2014) equates to a density of one Snow Leopard capable of reproduction per 710 km² or 1,320 km² respectively. We question how such a scenario would be demographically viable; and in fact, recent best-practice density estimates largely range from 1 to over 3 per 100 km² for areas surveyed to date (see below).

Doubt is also being cast on the lower estimates of the global Snow Leopard population size through the expansion of field surveys in recent years and the application of more sophisticated and reliable survey techniques (such as systematic camera trapping, faecal genotyping and satellite collaring). Recent studies have confirmed the presence of Snow Leopards in new areas or their reappearance in former areas. Snow Leopards returned to the Sagarmatha area, Nepal, in 2002-2003 after an absence of ca 25 years (Lovari et al. 2009, Ferretti et al. 2014). Snow Leopard presence in the Vakhan Range of Tajikistan was confirmed by camera-trapping for the first time in 2011 (Diment et al. 2012) and in the Kizilsu area of the Gissar Nature Reserve in Uzbekistan in 2013 (Panthera, unpublished data). In other areas, studies have indicated stable or even circumstantial evidence of increasing populations. In Wakhan District (10,000 km²) in Afghanistan, the National Environmental Protection Agency reports that numbers of Snow Leopards and one of their main prey, argali Ovis ammon, have increased in recent years (www.khaama.org 06 August 2015). The Snow Leopard population in Tost Uul, South Gobi, Mongolia, has been the object of the most intensive (and reliable) research to date using satellite collaring and camera trapping and was reported to be stable during the course of four years of study (Sharma et al. 2014). This site was completely unprotected until recently.

A review of the majority of camera trap and genetic surveys to date indicate densities in excess of 1.5 adults per 100 km². Densities of 0.87-2.85 and 0.32-1.62 per 100 km² were reported at two sites in the Eastern Pamirs (Kachel 2014). In Bhutan, there is a “bright future for Snow Leopards” (Wangchuk and Tharchen 2016) and density in Wangchuk Centennial Park, Bhutan was estimated at 2.39/100 km² by Shrestha et al. (2013). Thinley et al. (2014) found even higher densities in Bhutan’s Jigme Dorji National Park (6.2/100 km²) and estimated that the protected area could harbour as many as 192 Snow Leopards, which is nearly equal to the high end of the estimate for the entire country (200). At six sites in Ladakh-Spiti, India, densities were 0.45, 0.74, 1.17, 1.66, 1.94, and 3.3 per 100 km² (Suryawanshi et al. 2013). Density in Sarychat-Ertash State Reserve, Kyrgyzstan, was 1.38 per 100 km² (Jumabay-uulu et al. 2014), which is a reserve that Koshkarev and Vyrypaev (2000) pointed to as having been ‘absolutely trapped out’, with surveys in 1999 finding no sign of Snow Leopards after the post-Soviet declines earlier that decade.

In China, Snow Leopard presence has been confirmed at numerous locations across all parts of the range, including areas where the species was thought to have disappeared such as Inner Mongolia (Riordan and Shi 2016). The Second National Biodiversity Survey of China being undertaken by the State Forestry Administration suggests that there have been improvements for Snow Leopard and their ecosystems across the country since the first assessment reported in 1995. Snow Leopard populations in the Sanjiangyuan region are believed to have increased in the last 20 years along with those of a major prey species, Blue Sheep (Pseudois nayaur) (Liu et al. 2016). Camera-trap surveys in Suojia (also in Sanjiangyuan) indicated densities of 3.1/100 km² (Li 2012). Alexander et al. (2015), using spatially-explicit recapture models, reported 3.31 Snow Leopards/100 km² in the Qilian Shan range, where surveys in the 1980s suggested densities < 1/100 km². Schaller (2014) resurveyed portions of the Qilian Shan range in Qinghai 29 years after he first surveyed the area and although direct comparisons were not made they saw more Snow Leopard sign and more Blue Sheep in their recent surveys. Qinghai Forestry Department recently increased their estimate for the province to at least 1,000 individuals based on camera trapping surveys (Liu et al. 2016). Riordan and Shi (2016) estimate Snow Leopard populations for each province in China, totalling at least 4,500 for the whole country. Since China contains c. 60% of the overall range this figure implies that the global population may possibly reach 7,500, broadly in line with the upper estimates described above. The current situation for Snow Leopard in China is a result of new information emerging as survey effort improves, as well as positive effects of the illegalization of firearms in China in 1989, along with hunting bans in key provinces, and greater awareness of the national importance of Snow Leopards.

Some, but not all, of the recent studies have been in protected areas or locations thought to have good populations of Snow Leopards, so densities might be higher there than elsewhere, and thus these figures are not easily extrapolated to the entire range. However, taken together, and considering the widely spread localities within the overall distribution of Snow Leopards, these figures do seem to suggest that the global population size is closer to the upper end of the estimates cited above, rather than the lower end.

Two sets of global population estimates published in 2015, after the modelling exercise in Appendix 2 (in the Supporting Information) was carried out, also suggest that Snow Leopard numbers are higher than previously estimated in 2003. In 2008, an expert knowledge process was used to map current Snow Leopard range and identify important Snow Leopard Conservation Units (SLCUs) within that range (McCarthy et al. 2016). Experts from all range states and global experts participated and identified 69 SLCUs. Adequate information was available to estimate Snow Leopard population size in 56 SLCUs, placing it at 4,678 to 8,745 adults and large sub-adults within an area of 875,818 km², or about 31.5% of currently occupied range. The population trend was considered to be stable or increasing in 33 (48%) of SLCUs and decreasing in only 15 (22%), while no information on trend was reported by experts in 11 (30%) of the units. Notably, experts indicated that most population and trend estimates they provided came from recent research as opposed to previous ‘guesstimates’ lacking field-based evidence.

With the recent publication of the first ever comprehensive book on the species (McCarthy and Mallon 2016), additional light has been shed on current Snow Leopard population estimates in most of the 12 range countries. National experts authored individual chapters providing updates on the status of the species in their home countries. With the exception of Bhutan those chapters included current population estimates; taking the high and low values of the population ranges provided (Table 1 in the Supporting Information) a range-wide population of 7,367-7,884 is indicated. If the results of the 2014-2016 Bhutan Snow Leopard census are added in (79-112: Thinley et al. 2016), the global population would then be estimated at 7,446 to 7,996. This indicates that Snow Leopards are likely more numerous than historic estimates suggest, perhaps substantially so. It should be noted that this represents better knowledge and not necessarily a population increase.

There is little evidence to indicate that small-scale fragmentation and lack of connectivity are significant issues, despite the typically insular nature of mountain habitat and the species’ preference for steep or broken terrain. Most of Snow Leopard range is more or less contiguous and it is difficult to delimit separate subpopulations (Jackson, unpub. data; Janecka, unpub. data); furthermore, other than major rivers along the periphery of Snow Leopard range, some border fences, and short sections of railroads or major highways, there currently appear to be few major barriers to restrict movement. The Mongolia telemetry study has confirmed that Snow Leopards are capable of crossing open habitat (desert plains) in excess of 100 km (Panthera/SLT unpublished data) and Snow Leopards have been encountered attempting to cross the Chinese Gobi Desert in Inner Mongolia on at least three occasions (Riordan et al. 2015, Nei Mongol Wildlife Division, pers. comm). Riordan et al. (2015) used resistant kernel modelling to assess connectivity and predicted two regional populations, in the north and south of the species range, and identified several potentially important connecting areas. Snow Leopard range in Nepal lies in five “relatively contiguous habitat blocks” (Ale et al. 2016); in Pakistan, there is “confirmed presence over large landscapes” (Ud-Din and Nawaz. 2016); the range in Bhutan is virtually contiguous across the whole of the north of the country (Wangchuk and Tharchen 2016); in Sanjiangyuan region, a key Snow Leopard habitat in China, “there are abundant connections between important habitats” (Li 2012, Liu et al. 2016).

Current Population Trend:
Snow Leopard numbers are reportedly stable or modestly increasing in some areas, but are likely to be declining in others. Recent localized extinctions may have occurred in some areas of the former Soviet Union (Taubmann et al. 2016). Evidence of increased or re-established populations described above may in some cases be a consequence of enhanced survey effort in previously unsurveyed areas, although conservation actions and policies will have no doubt helped. However, there remains a lack of sufficiently longitudinal surveys, except in very few sites, and thus we have virtually no substantiated documentation of population trends over appropriate time scales. This is an information gap that urgently needs to be filled in order to validate this and all future Red List assessments and provide a reliable basis from which to evaluate conservation actions and measure their impact.

Population Reduction - Past
Population reductions in the Central Asian republics—which represent only 7% of the global occupied range (McCarthy et al. 2016)—following the collapse of the Soviet Union are thought to have been as high as 40-75% during the 1990s. There is no evidence to indicate such high rates of decline continued beyond the late 1990s.

Population Reduction - Future
Recent surveys in Pakistan suggest that Snow Leopard numbers in parts of the country may be lower than previously thought (Snow Leopard Foundation, unpublished reports, Nawaz and Hameed 2015) and may experience further decline in the future. Localized extinctions, such as those documented by Taubmann et al. (2016) in parts of the Alay region of Kyrgyzstan, may be expected in other isolated sites in Central Asia. There are also growing threats from extractive industries across the species’ range and potential impacts from climate change which may influence population trends. Despite positive conditions described previously, a decline of 10% over the next 3 generations (22.62 years) is estimated in light of localized declines given the growing threat related to increasing livestock numbers in some countries or emerging threats like intensified road construction and mineral extraction (see below). However, projecting rural development more than 3-5 years into the future is difficult, even in countries with well-articulated 5-10 year Development Plans, environmental impact laws or robust protocols for forecasting economic growth.
 
Population Reduction - Ongoing
Current reductions appear to be modest and local, likely driven by a declining natural prey base, localized poaching for skins, and sporadic but apparently increasing human-wildlife conflict resulting from depredation of livestock. Growing flocks of sheep and goats and a thriving meat (e.g., Nepal and Pakistan) and cashmere trade (China and Mongolia) appear to lie at the root of these inter-connected threats (Berger et al. 2013). However, where not mitigated, the mix of livestock-wild ungulate competition, associated rangeland degradation, declining natural prey numbers and Snow Leopard predation of livestock would likely accelerate retributive killing by herders, who could also be expected to offset their economic losses by funnelling Snow Leopard body parts into the illegal trade network.

Snow Leopards inhabit mountainous rangelands at elevations of 3,000 to over 5,000 m in the Himalaya and Tibetan Plateau, but can occur as low as 500 m in the Altai (Snow Leopard Network 2014). Wild caprids are the principal natural prey of Snow Leopards, especially Blue Sheep (Pseudois nayaur) and Siberian Ibex (Capra sibirica), whose distribution coincides closely with Snow Leopard range. Argali (Ovis ammon) and Markhor (Capra falconeri) are also important prey in some areas. Primary productivity in Snow Leopard habitat is relatively low due to low temperatures and high aridity, consequently, the density of ungulate prey also tends to be relatively low, with reports ranging from 0.9 to 10.2 animals per km² (e.g., Suryawanshi et al. 2013, Mallon et al. 2016). Wild prey abundance is one of the main determinants of Snow Leopard abundance (Suryawanshi et al. 2013).

Snow Leopard diet is dominated by wild caprids, reportedly contributing 45% to 98% of the diet, while livestock may contribute 40-70%, though generally more on the order of 15-30% (Schaller et al. 1987, Oli et al. 1994, Chundawat and Rawat 1994, Jackson 1996, Bagchi and Mishra 2006, Anwar et al. 2011, Shezad et al. 2012, Jumabay-Uulu et al. 2014, Suryawanshi et al. 2013, Mallon et al. 2016). Smaller prey reported in Snow Leopard diet (approximately 12–25%) include marmots (Marmota spp.), pika (Ochotona spp.), hares (Lepus spp.), small rodents, and birds. It appears that the contribution of small sized prey in Snow Leopard diet may have been overestimated in earlier studies due to inadvertent inclusion of scats of other carnivores such as foxes (Vulpes spp.) in the analyses of Snow Leopard diet. Results of recent studies that have confirmed the identity of scats through faecal DNA (e.g., Anwar et al. 2011, Jumabay-Uulu et al. 2014, Suryawanshi et al. 2013) or examined prey DNA in scats (Shezad et al. 2012) report the contribution of small sized prey to be relatively low (2-8%).

Although Snow Leopards may occur in relatively flat or rolling areas such as in parts of Mongolia and the Tibetan Plateau (Schaller 1998, McCarthy 2000), within their habitat, they favour steep, rugged and broken terrain and rocky outcrops (Jackson et al. 2010). Mountain ridges, cliff edges, and well-defined drainage lines serve as common travel routes and sites for the deposition of signs, including scrapes, scats, and scent marks (Ahlborn and Jackson 1988).

There is substantial variation in the reported home range sizes of Snow Leopards. An earlier study in Nepal based on ground-based very high frequency (VHF) tracking reported home ranges of five individuals between 12 and 39 km², with substantial overlap between individuals and sexes (Jackson and Ahlborn 1989). However, the home range of a single Snow Leopard radio-collared in 2013 in Nepal using a satellite collar was estimated to be > 400 km² (Rinjan Shreshtha, WWF, pers. comm). McCarthy et al. (2005) reported home range size of four Snow Leopards based on VHF tracking in Mongolia to range between 13 and 141 km², while the satellite-monitored home range of one of these individuals in the same study was at least 15 times higher. In the most current and comprehensive study to have been undertaken, home ranges of 18 individuals monitored between 2008 and 2014 using Global Positioning System (GPS) Satellite telemetry in Mongolia ranged from approximately 100 to >1,000 km² (SLT, Panthera and SLCF, unpubl. data).

A four-year camera trapping study in Mongolia reveals considerable underlying dynamics in an otherwise stable population of Snow Leopards, with the adult sex ratio apparently changing from being male-biased to female-biased during the study period (1.67 to 0.38 males per female, Sharma et al. 2014). This is the first study to estimate vital rates including probabilities of immigration and emigration. The adult survival probability for the study population was estimated at 0.83 (Sharma et al. 2014).

Appendix 2 of the Snow Leopard Survival Strategy (Snow Leopard Network 2014) provides a global and country-by-country threat assessment based on the GSLEP-supported exercise drawing loosely on the Threats Reduction Assessment (TRA) protocol of Salafsky and Margoluis (1999) and involving select experts from each range country. McCarthy and Mallon (2016) include several chapters exploring well-known and emerging threats including livestock depredation, prey declines, disease, illegal trade, climate change, and resource extraction. There is considerable variation in the type and extent of threat among countries, especially with respect to large countries such as China or Mongolia where suitable habitat is extensive and split across different administrative regions. The main ongoing threats fall into three broad areas: 1) competition with livestock, habitat degradation and declines in prey; 2) depredation by Snow Leopards on livestock and retaliatory killing; 3) illegal trade in furs, bones and other body parts. New threats have been identified since 2003, including climate change, mining, large scale infrastructure and barriers such as roads or fenced railway lines (Wingard et al. 2014, Zahler 2016); however, the potential impact of these emerging threats on Snow Leopards or their habitat is as yet difficult to quantify. A further set of threats regarded as less severe at the range-wide level, or at least more localized, include the lack of awareness among local people and policymakers, insufficient institutional capacity and law enforcement, and limited transboundary collaboration.

Specific threats to particular populations are outlined below:

Recently Nowell et al. (2016) found that over 90% of annual Snow Leopard poaching is estimated to occur in five range countries: China (103-236 animals poached per year), Mongolia (34-53), Pakistan (23-53), India (21-45) and Tajikistan (20-25). While the highest levels of poaching and illegal trade are in China, which has the largest share of Snow Leopard range, countries with smaller shares of global range were flagged for having disproportionately high levels of estimated poaching (Nepal and Pakistan) and illegal Snow Leopard trade (Afghanistan and Russia). Afghanistan, Bhutan and Kazakhstan had markedly low levels of seizures compared to observations of poaching and illegal trade, suggesting the need for strengthened law enforcement in these countries (Nowell et al. 2016).

Poaching and illegal trade has been a traditional threat and continues in many parts of the range. Currently, the demand for rugs, luxury décor, and taxidermy, especially from China and Eastern Europe appears on the increase (EIA 2012). In China, that holds the largest Snow Leopard population, trade in Snow Leopard pelt and bones, which was earlier restricted to Snow Leopard range provinces, is reported to also be emerging in the wealthier coastal cities since 2010 (Li and Lu 2014). The extent of illegal trade was reviewed by Maheshwari and Von Meibom (2016).

Very significant investments in conservation have been made. These include: establishment of new protected areas within the Snow Leopard range; anti-poaching measures; training and capacity-building; initiatives to reduce conflict with herders (e.g. strengthening livestock corrals, vaccination, handicrafts and alternative livelihoods, grazing set-asides), community engagement programmes; illegalization and confiscation of firearms across China, and education programmes to raise awareness of the Snow Leopard and its habitat (see Conservation Measures section for more details and examples). The Rangewide Priority Setting workshop in Beijing in 2008 (Sanderson et al. 2016), the Global Snow Leopard and Ecosystem Protection Program (Snow Leopard Working Secretariat 2013) and the revised version of the Snow Leopard Survival Strategy (Snow Leopard Network 2014) have all enhanced the global strategic framework for conservation of the species.

Illegal poaching, the main threat to Russia's Snow Leopard population, was recently alleviated, at least in several important areas, by concerted removal of wire-snares and the recruitment of former poachers as protected area rangers (Paltsyn et al. 2016). Anti-poaching efforts in Tajikistan, Kyrgyzstan and Kazakhstan have also been strengthened, thus addressing the main underlying threat that led to the drastic decline in numbers in several Central Asia states following the break-up of the Soviet Union 25 years ago.

In terms of protected area establishment and enhancement, the whole of Wakhan District Afghanistan (>10,000 km²) has been declared the country’s second national park (Moheb and Paley 2016). Sarychat Ertash State Reserve, a key site in Kyrgyzstan, has recently been enlarged by 150 km² and mining concessions withdrawn (www.snowleopard.org 3 June 2015), and several projects have worked on management planning, training and monitoring and/ or provided substantial amounts of equipment (Hotham et al. 2016). Tost Uul, a key site in Mongolia’s South Gobi, was declared a local nature reserve in 2010 (www.snowleopard.org, 4 October 2015). Capacity building in Zorkul State Reserve in the Eastern Pamir of Tajikistan includes development of a new management plan, training programmes, and substantial donations of equipment (Mallon and Diment 2013). The role of Buddhist monasteries in providing effective protection around monasteries was highlighted by Li et al. (2014). The GSLEP initiative, along with conservation practitioners have been highlighting customary beliefs of Snow Leopards as important totem animals for select traditional communities across this species' range.

A number of transboundary projects provide important conservation benefits to Snow Leopards across their range (Rosen and Zahler 2016). Two transboundary or landscape-level projects are currently operating in Central Asia (Mallon and Kulikov 2015): The Khan Tengri nature conservation park (3,257 km²) has been designated in eastern Kyrgyzstan that will link Naryn Reserve, Sarychat Ertash Reserve, and two others in Kyrgyzstan with Tomur Nature Reserve in China; a transboundary project is currently operating in the northern Tien Shan (Kyrgyzstan and Kazakhstan) with Snow Leopard as a focal species and with the aim of developing cooperation and enhancing protected areas. The UNDP/GEF Altai-Sayan Project (2007-2012) also identified the Snow Leopard as one of its focal species and carried out a series of transboundary projects including camera trapping, and training (WWF 2012).

Many incentive programs have been initiated (reviewed in Mishra et al. 2003 and see chapters in McCarthy and Mallon 2016). One oft-cited threat is the killing of Snow Leopards by herders in retaliation for predation on livestock, exacerbated by occasions when many sheep or goats are killed in a single attack by a Snow Leopard gaining entry to poorly constructed or maintained night-time corrals. Remedial measures have involved strengthening corrals to make them predator-proof. To date, over 260 corrals have been strengthened in Afghanistan, India, Pakistan and Tajikistan with the result that no subsequent livestock predation occurred (Mohammad et al. 2016, Moheb and Paley 2016). A similar programme in Western Tyva, Russia protected corrals in 46 herder camps, and since 2008 no predation occurred in any of them and annual losses of livestock fell by 50-60% (Paltsyn et al. 2016).

Innovative community programmes have been established in Afghanistan and Pakistan, with new governance structures created (over 65 in Pakistan) aimed at local natural resource management, and with over 50 rangers in the Afghan Wakhan and over 100 rangers in Gilgit-Baltistan, Pakistan monitoring wildlife and enforcing local and national regulations against poaching and other resource extraction activities (Zahler and Paley 2016). A programme has been pioneered by the Snow Leopard Trust in Mongolia and Kyrgyzstan to increase local incomes by providing training in the manufacture of handicrafts and access for the finished products to international markets in return for a commitment to prevent poaching of Snow Leopards and their prey and to engage in environmental education and other activities. These programmes have proved successful and have had additional benefits (Bayarjargal et al. 2016). In Kyrgyzstan, no Snow Leopards or prey were poached during 2014 in any of the partner communities (www.snowleopard.org 3 June 2015). Incentives related to ecotourism have led to a surge in Snow Leopard sightings in Hemis National Park, Ladakh (India), attributed to a combination of corral predator-proofing and meaningful income generation associated with community-managed homestays first initiated in 2007 (Jackson and Wangchuk 2004, Wangchuk et al. 2010, Jackson 2015, Namgail and Dadul 2016). With these local communities now perceiving Snow Leopards positively instead of pests to be killed or chased away, this notoriously elusive big cat is now being regularly observed from distances as close as 50-200 meters, especially during its mating season in winter.

In addition to these programmes, other conservation initiatives include grazing set-asides (village reserves; Mishra et al. 2016), livestock vaccination (Nawaz et al. 2016), livestock insurance (Kunkel et al. 2016) and a range of education and awareness projects (Hillard et al. 2016). Conservation initiatives that blend conservation science with traditional knowledge, and which mitigate Snow Leopard-related human-wildlife conflict, improve household incomes for households dependent upon livestock, and that highlight the cultural and ecological importance of Snow Leopards are also most likely to be embraced by local people who likely represent the effective and cost-efficient stewards for this felid's remote mountain landscapes (Jackson and Brewer-Lama 2016).