Taxonomic Notes
The Indochinese Leopard (Panthera pardus delacouri) has been classified as a separate subspecies based on genetic analyses (Miththapala et al. 1996, Uphyrkina et al. 2001) and its status as a subspecies recently was retained conservatively, pending further taxonomic investigation, in a review commissioned by the Cat Classification Task Force of the IUCN SSC Cat Specialist Group (Kitchener et al. 2017).
The distributional limits of P. p. delacouri are rather arbitrary, reflecting the paucity of critically validated specimens over much of the subspecies’ putative range. Rostro-García et al. (2016) defined the Pearl River in southern China as the northern limit, and Singapore as the southern limit of the subspecies. In addition, the authors delineated the western border of Myanmar as the western limit of the subspecies, as suggested by Miththapala et al. (1996) and Uphyrkina et al. (2001). However, Kitchener et al. (2017) defined the western limit of the subspecies as the Irrawady river in Myanmar, with P. p. fusca occurring on the western side of the river. Because the revised taxonomy of the Felidae by Kitchener et al. (2017) has been formally adopted as the current cat classification used by the IUCN SSC Cat Specialist Group and Red List Authority, the western limit of P. p. delacouri shown by Kitchener et al. (2017) is followed here.
Justification
The Indochinese Leopard is listed as Critically Endangered under criteria A2b+3b+4b, based on a suspected population decline greater than 80% over the last three generations, and that the causes of reduction have not ceased and may not cease in the future. The three generation period for assessment was considered to be about 22 years, based on the generation length of 7.4 years previously reported for the species (Stein et al. 2016).
The Indochinese Leopard once ranged widely across Southeast Asia and southeastern China (Nowell and Jackson 1996), but now occurs in only a small fraction (about 2%–6%) of its historical distribution (i.e. range prior to 1900). Remaining populations are small and isolated. This Leopard subspecies has been extirpated in Singapore, quite probably extirpated as a resident
Although a range-wide rate of population decline over the last three generations cannot be appropriately quantified, evidence from well-monitored localities indicates rapid ongoing declines where the Leopard still occurs in Southeast Asia. For example, Leopard densities decreased by 38% in three years at a site in Thailand (Simcharoen and Duangchantrasiri 2008), 44% in two years at a site in Malaysia (Hedges et al. 2015, Rimba unpubl. data), and 72% in five years at a site in Cambodia (Rostro-García et al. 2018) (see ‘Population’ for further detail). There is no obvious reason to assume that these localities are unrepresentative of Leopard population trend in Southeast Asia and adjacent China, nor that they represented anomalies in longer-term trends at the localities in question. All are consistent with a population decline in the last three generations exceeding 80%. On this basis, the taxon is categorised as Critically Endangered under A2b.
In the face of the continuing threats, the population decline of the Indochinese Leopard is likely to persist unless immediate conservation actions are taken. Despite considerable investment in this taxon’s range over the last two decades, the slow pace of conservation success gives little cause to suspect a region-wide major upswing over the next two decades. Notwithstanding the probability of some location-specific successes, this subspecies’ recent rate of decline is likely to continue with little change, thus a further decline of 80% over the next three generations is suspected, qualifying it as Critically Endangered also under A3b and A4b.
Geographic Range Information
The geographic range of the Indochinese Leopard was recently described by Rostro-García et al. (2016). This assessment uses the data obtained by Rostro-García et al. (2016), and additional data collected since 2015 using the same methodologies.
Cambodia: Leopard now occurs in about 4% of the country, with an estimated range of around 7,932 km² (extant = 6,008 km², possibly extant = 1,924 km²). There appears to be only one remaining breeding population in the country, which is small and occurs within two protected areas of the Eastern Plains Landscape. In addition to that published by Rostro-García et al. (2016), the Leopard is now possibly extinct in the following five sites: Lomphat Wildlife Sanctuary, Keo Seima Wildlife Sanctuary, Chhlong area, Kien Svay District, and Prey Khieu Forest. The latter three sites are unprotected areas that have experienced extensive human disturbance during the past 10 years, including land encroachment, logging, and poaching (Forestry Administration, unpubl. data), and it is unlikely that Leopard still occurs there. Within the Eastern Plains Landscape, Leopard has not been detected within Lomphat Wildlife Sanctuary and Keo Seima Wildlife Sanctuary during the past 10 years despite occasional camera trapping, during a period in which both protected areas experienced significant increases in land encroachment, logging, and poaching (WCS Cambodia and BirdLife International, unpubl. data). Although Leopard was detected in Chhep Wildlife Sanctuary (formerly Preah Vihear Protected Forest) in 2013 and 2014 (Suzuki et al. 2017), it was not detected in 2015, suggesting that only a few individuals, if any, may occur there. Therefore, Chhep Wildlife Sanctuary is classified as possibly extant. In Srepok Wildlife Sanctuary (formerly Mondulkiri Protected Forest) and Phnom Prich Wildlife Sanctuary, both within the Eastern Plains Landscape, camera trap surveys detected Leopard in 2016 and 2018 (Panthera, WildCRU, WWF Cambodia and Ministry of Environment, unpubl. data), and this area is likely to contain the last remaining breeding population of Leopard in Cambodia. At these monitored localities recent steep population declines (see ‘Population’) suggest that the Leopard will probably be extirpated soon from both protected areas unless immediate conservation action is taken.
China: Leopard now occurs in less than 1% of southeastern China, with an estimated extant range of 2,483 km², as reported by Rostro-García et al. (2016). A recent review found the Indochinese Leopard was detected by camera traps only in two nature reserves, Nangunhe (2012–14) and Xishuangbanna (2008), both in southwestern Yunnan Province (Laguardia et al. 2017). Laguardia et al. (2017) concluded that each locality contains only a few individuals (fewer than 10 individuals apiece) and populations are unlikely to recover because of low prey numbers, and high levels of habitat loss and poaching in the region. Thus, the Indochinese Leopard probably is on the verge of extirpation in the country (Rostro-García et al. 2016).
Lao PDR: There are unlikely to be any viable Leopard populations remaining in Lao PDR, and the Leopard is now likely to be functionally extinct in, if not fully extirpated from, the country (Rostro-García et al. 2016). Leopard was last photographed in 2004 in the Nam Et – Phou Louey (NEPL) National Protected Area, the largest and arguably best protected area in the country (Johnson et al. 2006), despite extensive camera-trapping and DNA testing of more than 500 scats since that time (WCS Lao PDR and Panthera, unpubl. data). Increases in snaring caused the extirpation of Tiger Panthera tigris in NEPL, the last remaining population of this species in Lao PDR (Johnson et al. 2016), and plausibly caused the extirpation of Leopard in NEPL as well. Although several areas of presumably suitable Leopard habitat in Lao PDR remain inadequately surveyed to know the status of the species within them, Leopard is unlikely to occur in a viable population within any of these areas, especially given that recent surveys have targeted the largest protected areas in the most remote regions of the country (e.g., NEPL and Nakai - Nam Theun National Protected Area). Leopard seemingly has disappeared from areas that appear to contain sufficient habitat and prey (e.g., NEPL), suggesting that local extirpations were likely to have been caused by poaching for the wildlife trade, similar to that observed in Cambodia (Rostro-García et al. 2016).
Malaysia: Leopard now occurs in about 36% of peninsular Malaysia (it did not occur in Borneo during historical times), with an estimated range of around 47,076 km² (extant = 12,365 km², possibly extant = 34,711 km²), as reported by Rostro-García et al. (2016). In contrast to other countries in Southeast Asia, Leopard still occurs throughout many forests in the country, including large complexes in the north (Belum-Temengor), central (Taman Negara), and south (Endau-Rompin), as well as in fragmented and secondary forests throughout the country (Rostro-García et al. 2016). Outside the three major protected-area complexes, Leopard was detected in 64% (9 of 14) of surveyed sites (Rostro-García et al. 2016). Because most forested areas outside protected areas have not been surveyed, these areas were categorised as possibly extant, unless Leopard was not detected in surveys within a specific site, given that poaching is presumed not to be as extensive as in other countries of Southeast Asia. Thus, peninsular Malaysia is considered one of the remaining strongholds for the Indochinese Leopard, although the populations are under threat from poaching. Recent increases in poaching in Malaysia might be causing considerable declines in Leopard numbers, similar to that reported for Tiger (Kawanishi 2015). At one of the best-monitored localities, Leopard numbers showed a recent steep decline (see ‘Population’). In addition, there have been recent seizures of Leopard carcasses with snare marking in the country (TRAFFIC 2013) indicating snaring might be a considerable threat to Leopard in Malaysia.
Myanmar: Leopard now occurs in about 15% of its historical range in the country, with an estimated range of around 56,330 km² (extant = 13,217 km², possibly extant = 43,113 km²). From 1999 to 2004, Indochinese Leopard was detected in only 5 of 18 survey areas located throughout the country (Than Zaw et al. 2014), and its distribution is likely to have decreased since that time because of increased poaching, similar to that reported for Tiger in Myanmar (Lynam 2010). The Southern Forest Complex presumably contains the largest viable population of Leopard in the country (Rostro-García et al. 2016). This complex, which extends southwards in Myanmar to Lenya National Park, is contiguous with two large complexes in Thailand, which together comprise the Northern Tenasserim Forest Complex. Outside this complex, only one area, the northern Karen (Kayin) State, may hold a potentially viable population of Indochinese Leopard. This conclusion is based on recent Leopard records, size of area protected, prey availability, habitat quality, levels of human disturbance, and levels of effective enforcement.
Singapore: Leopard historically occurred in Singapore, but was extirpated from the island state as it developed (Corlett 1992).
Thailand: Leopard now occurs in about 5% of the country, with an estimated range of around 26,259 km² (extant = 16,196 km², possibly extant = 10,063 km²). Compared with that published by Rostro-García et al. (2016), we infer Leopard is now possibly extinct from the Khlong Saeng-Khao Sok Complex because extensive camera-trap surveys in 2017 did not detect Leopard in either Khlong Saeng Wildlife Sanctuary or Khlong Nakha Wildlife Sanctuary (Panthera, WildCRU, ZSL Thailand and DNPWPC, unpubl. data). In contrast, we included the Namtok Huai Yang National Park in the extant range because camera-trap surveys in 2017 recorded Leopard there (Freeland unpubl. data). We conclude that viable Leopard populations now occur in only 2 of 19 protected area complexes located in Thailand: Western Forest Complex (WEFCOM) and Kaeng Krachan-Kuiburi Complex (KKC). The KKC and WEFCOM, together with the Southern Forest Complex in Myanmar, comprise the Northern Tenasserim Forest Complex, which might contain the largest remaining population of Indochinese Leopard, and thus is considered one of the remaining strongholds for this subspecies. The WEFCOM is the largest complex in Thailand where Leopard still occurs, and within this complex Huai Kha Khaeng Wildlife Sanctuary is the best protected park (Duangchantrasiri et al. 2016) and probably has the highest Leopard density (Simcharoen and Duangchantrasiri 2008). However, Leopard was not detected in all protected areas that were adequately surveyed within WEFCOM (Rostro-García et al. 2016), indicating it might be under threat within some protected areas that are part of the complex. Within KKC, Kuiburi National Park was reported to have relatively high Leopard densities (Steinmetz et al. 2009), although the current density is unknown. Outside these complexes, Leopard was recently detected in Hala Bala Wildlife Sanctuary (southern peninsula), and Salawin National Park (northwestern Thailand, Rostro-García et al. 2016). These protected areas, as well as the Namtok Huai Yang National Park (northern peninsula), are on the border with Malaysia or Myanmar, and thus are part of larger transboundary populations.
Viet Nam: There are no known viable Leopard populations remaining in Viet Nam, and this species is now likely to have been extirpated from the country (Rostro-García et al. 2016). From 1995 to 2013, there were no photographs of Leopard from camera-trapping studies in the country, including those in the largest and best protected areas (Rostro-García et al. 2016). The last published record of Leopard from Viet Nam was probably from the early 2000s in Yok Don National Park, in central Viet Nam (Eames et al. 2004), which might have been transient Leopard originating from the adjacent population in eastern Cambodia. It is doubtful that Leopard still occurs as a resident in Viet Nam given high levels of hunting and snaring there, which have devastated populations of smaller cat species in the country (Willcox et al. 2014).
The Indochinese Leopard occupies forest habitats down to sea-level. The upper altitudinal limit is not known. The Indian Leopard (P. pardus fusca) inhabits forests up to the tree line throughout the Himalayan region with a maximum elevation of 5,200 m (Nowell and Jackson 1996). Consequently, the Indochinese Leopard is likely to have occurred up to the tree line in northern Myanmar and adjacent areas of China, although no extant high altitude population is known.
Note: Additional data could result in an increase or decrease in population size or range loss of the Indochinese Leopard in certain areas.
Population Information
The population of the Indochinese Leopard was estimated in 2015 to be 973–2,503 individuals, with 409–1,051 breeding adults (Rostro-García et al. 2016). However, Rostro-García et al. (2016) delineated the western limit of the Indochinese Leopard as the western border of Myanmar as suggested by Miththapala et al. (1996) and Uphyrkina et al. (2001), and therefore the estimate reported is not comparable with the present account. In this assessment, the Indochinese Leopard distribution was updated with the western limit delineated by Kitchener et al. (2017) and using additional data collected since 2015. In addition, the methodology used by Rostro-García et al. (2016) to estimate Leopard population size was modified. Following Rostro-García et al.(2016), we multiplied the area of distribution by an inferred density range. Results from previous camera-trap surveys across the region showed Leopard densities typically ranged from 0.5 to 4.9 Leopard/100 km² (Simcharoen and Duangchantrasiri 2008, Steinmentz et al. 2009, Gray and Prum 2012, Hedges et al. 2015, Rostro-García et al.2018, WildCRU, Panthera, WWF Cambodia and Ministry of Environment, unpubl. data). Therefore, we used a density range of 0.5–5.0 Leopard/100 km² for calculating the current population sizes within each country of its distribution. Because Leopard does not occupy sites uniformly when factors such as Tiger densities, prey densities, habitat, and human disturbance are considered (Steinmetz et al. 2013, Carter et al. 2015), we calculated population size assuming 45% occupancy for areas within the current distribution. We selected 45% occupancy because it was the approximate midpoint of the range of occupancies reported in previous camera trap studies of Leopard in Asia (Carter et al. 2015, Steinmetz et al. 2013, WildCRU, Panthera, WWF Cambodia and Ministry of Environment, unpubl. data).
There are no robust estimates of the total number of mature Leopard individuals range-wide nor of the percentage of mature individuals in Leopard populations. Therefore, we followed the procedure used to estimate the percentage of mature individuals in populations of Snow Leopard (Panthera uncia, McCarthy et al. 2017), a species of the same genus. Leopard in the wild breeds first between 2 and 4 years of age (Balme et al. 2013), similar to that reported for Snow Leopard and other large cats (McCarthy et al. 2017). Therefore, we assumed that Indochinese Leopard is capable of breeding beginning at two years of age, and thus meets the IUCN definition of mature individual, even if no breeding occurs at this age. Population modelling for Snow Leopard showed that the most conservative estimate was a mean of 67.7% mature individuals in the population, based on when 2-year old maturity rates were lowest (25%), actual breeding did not begin until age 3-year, and the proportion of cubs in the population estimate was highest (50%, McCarthy et al. 2017). We assumed that percentage of mature individuals was similar in Indochinese Leopard populations, and therefore used 68% to estimate numbers of mature individuals.
Following the IUCN Red List Guidelines (IUCN Standards and Petitions Subcommittee 2017), we estimated the total population in 2019 to be 114–1,130 individuals, including 77–766 mature individuals, based on the current extant range (i.e., possibly extant range was not included in the total population size) given within ‘Distribution’.
An attempt was made to estimate the recent range-wide change in population, based on occupation of range, but this method was not suitable because of major differences between years in the mapping protocols. The only available distribution map of the Indochinese Leopard from about three generations ago showed a complete distribution across mainland Southeast Asia (Nowell and Jackson 1996). However, there were gaps in the Leopard distribution already by this time, because illegal hunting for traditional medicine was already occurring throughout the region (Nowell and Jackson 1996). In addition, the main period of natural habitat loss in the range countries of the Indochinese Leopard had already occurred by the 1970s. Because information about where in Southeast Asia the Leopard was surviving was unavailable, the 1996 map cross-shaded all of mainland Southeast Asia, with the footnote ‘abundance reduced, populations strongly localized’. Consequently, the distribution map of Nowell and Jackson (1996) cannot be compared with that made for this 2019 account to estimate the contraction of range within the region. The only updated map of Leopard distribution in Southeast Asia since 1996 is that published in the IUCN Red List assessment for the species in 2008 (Henschel et al. 2008). In this map extensive areas of Southeast Asia were retained as ‘extant’ although the Leopard was likely to have been extirpated, or persisting in only highly fragmented populations across many areas of the region by that time (e.g. most of Lao PDR, Viet Nam and northern Thailand). Only the most obviously unsuitable areas were not shaded in this 2008 map, such as large agricultural or urban areas of the region. The 2019 Red List map was made using reliable, up-to-date information derived from an extensive review, which resulted in a more realistic, representation of Leopard distribution in Southeast Asia and adjacent China than had been presented in 1996 or 2008. A shift from mapping areas with uncertainty from “benefit-of-the-doubt” presence to likely absent, precludes any meaningful quantification of the change in range occupancy between the current and previous maps. Although the severity of the decline in occupancy over the last three generations cannot appropriately be quantified, evidence from well-monitored localities indicates rapid ongoing declines where the Leopard still occurs in Southeast Asia. For example, in addition to the apparent extirpation of Leopard from Lao PDR and Viet Nam over the last three generations, there is ample and geographically wide-spread evidence that the remaining populations in the region are in steep ongoing decline. In Cambodia, the population in Srepok Wildlife Sanctuary declined by 72% from 2009 to 2014 because of increases in poaching (Rostro-García et al. 2018), along with a similar decrease in Phnom Prich Wildlife Sanctuary (WildCRU, Panthera, WWF Cambodia and Ministry of Environment, unpubl. data). In Kenyir Wildlife Corridor, adjacent to Taman Negara, Malaysia, there was a 100% turnover in the Leopard population over two years (2013–2015), which coincided with a 44% decline in density (Hedges et al. 2015, Rimba unpubl. data), indicating high mortality. Similarly, Leopard densities appeared to decrease by 38% in three years in Huai Kha Kaeng Wildlife Sanctuary, Thailand (Simcharoen and Duangchantrasiri 2008). There is no obvious reason to assume that these localities are unrepresentative of the overall Leopard population trend in Southeast Asia and adjacent China, nor that they represented anomalies in longer-term trends at the localities in question. All this information is consistent with a population decline in the last three generations exceeding 80%.
Note: Additional data could result in an increase or decrease in population size or range loss of the Indochinese Leopard in certain areas.
See Supporting Material for national population estimates of the Indochinese Leopard.
Habitat and Ecology Information
Habitat Types
The Indochinese Leopard is a habitat generalist and can occur in almost any habitat type in Southeast Asia, including primary and secondary forests, tropical dry and moist deciduous forests, evergreen and semi-evergreen forests, and plantations. In Cambodia, China, and Thailand, Leopard distribution now is restricted to protected areas. In Malaysia and Myanmar, although primarily restricted to protected areas, Leopard also occurs in unprotected forests (Rostro-García et al. 2016) and even palm plantations (Azhar et al. 2014), although it is doubtful that viable populations occur in the latter habitat type.
Diet
Although Leopard preys preferentially upon species weighing 10–40 kg (Hayward et al. 2006), the diet of the Indochinese Leopard appears to vary according to habitat type, prey availability, and presence of larger carnivores. In protected areas in western Thailand, where Tiger was present and the main habitat was evergreen forest, the main prey of Leopard was primates, small to medium ungulates, and small carnivores (Rabinowitz 1989, Grassman 1999, Steinmetz et al. 2013, Lovari and Mori 2017). In contrast, in a protected area in eastern Cambodia that was dominated by open dry deciduous forests, and from which Tiger was recently extirpated, the main prey of Leopard was medium to large ungulates (Rostro-García et al. 2018). In fact, the main prey of Leopard in this population was Banteng (Bos javanicus), making this the only known Leopard population in the world that had main prey weighing greater than 500 kg (Rostro-García et al. 2018). Rostro-García et al. (2018) also showed that male Leopards, which can be 30–50% larger than female Leopards (Skinner and Chimimba 2005), had a different diet from that of females. Male Leopards consumed mostly Banteng, and preyed on all ungulates approximately in proportion to availability. In contrast, female Leopards consumed Northern Red Muntjac (Muntiacus vaginalis) more than expected, and avoided Banteng (Rostro-García et al. 2018). Leopard in other regions was shown to consume larger prey in the absence of larger carnivores (Harihar et al. 2011, Mondal et al. 2012, Stein and Hayssen 2013, Mann 2014), thus it was likely that after the extirpation of Tiger, male Leopard in eastern Cambodia expanded its dietary niche, and consumed large prey such as Banteng. Overall, the dietary studies of the Indochinese Leopard showed a highly varied diet, with prey ranging in size from insects to Banteng, owing to the opportunistic nature of the species.
Home Ranges and Activity
Home range size of Leopard varies with prey availability, habitat types, age, and season. Also, male home ranges tend to be larger than females at any given site. For the Indochinese Leopard, home ranges have been determined only for radio-collared individuals in western Thailand. In Huai Kha Khaeng Wildlife Sanctuary, home ranges varied from 27–56 km² for males and 11–41 km² for females (Rabinowitz 1989, Simcharoen et al.2008). In Kaeng Krachan National Park, home ranges were 17–18 km² for two males and 9 km² for one female (Grassman 1999). Subadult females were found to reside within their respective mother’s territories and had home ranges within the general size range of adult females (Simcharoen et al. 2008). These studies showed that home ranges increased significantly during the wet season for males, but not for females (Rabinowitz 1989, Grassman 1999, Simcharoen et al. 2008).
In protected areas in western Thailand, Indochinese Leopard activity was found to be either arrhythmic or mostly diurnal and crepuscular (Rabinowitz 1989, Grassman 1999, Ngoprasert et al. 2007). In contrast, Leopard in eastern Cambodia was found to be mostly nocturnal (WildCRU, Panthera, WWF Cambodia and Ministry of Environment unpubl. data) probably due to higher levels of human activity and persecution compared with those in the protected areas in Thailand.
Densities
Reported densities of the Indochinese Leopard range from 1.0 to 7.9 Leopards/100 km² (Simcharoen and Duangchantrasiri 2008, Rostro-García et al.2018). In Cambodia, densities in Srepok Wildlife Sanctuary ranged from 3.6 Leopards/100 km² in 2009 (Gray and Prum 2012) to 1.0 Leopards/100 km² in 2014 (Rostro-García et al.2018). In Malaysia, densities in Kenyir Wildlife Corridor, adjacent to Taman Negara, Malaysia, ranged from 3.0 Leopards/100 km² in 2013 (Hedges et al.2015) to 1.7 Leopards/100 km² in 2015 (Rimba, unpubl. data). In Thailand, densities have been estimated to be 7.9 Leopards/100 km² in 1996 and 4.9 Leopards/100 km² 1999 in Huai Kha Kaeng Wildlife Sanctuary (Simcharoen and Duangchantrasiri 2008), and to range from 3.3 to 4.8 Leopards/100 km² in 2007 and 2009, respectively, in Kuiburi National Park (Steinmetz et al. 2009). Overall, densities of the Indochinese Leopard appear to be strongly affected by the poaching of Leopard and its prey, thus the density of Leopard in the absence of these human impacts is unknown.
Melanism
In contrast to all other mainland Leopard subspecies throughout the world, the Indochinese Leopard is unique in that a large percentage of remaining individuals are melanistic, including nearly 100% of the individuals in the Malay Peninsula (Kawanishi et al. 2010). The exceptions are the populations of the Indochinese Leopard in the open dry deciduous forests of eastern and northern Cambodia, in which all individuals are spotted. It has been hypothesized that melanism in the Indochinese Leopard was an adaptation to the closed canopy of tropical evergreen forests in Southeast Asia, thereby allowing better concealment of Leopard to ambush prey or avoid dominant Tiger in shadowy habitats where light seldom penetrates to the forest floor (Kawanishi et al. 2010). More recent research suggests that melanism is an adaptation in Leopard that helps with thermoregulation in hot humid forests in addition to camouflage (da Silva et al. 2017), thus there may be multiple benefits for the same gene expression. Both hypotheses would explain why melanism is absent from Indochinese Leopard inhabiting northern and eastern Cambodia, because these forests are both open and dry. That melanism is present in a large percentage of the Indochinese Leopard individuals, and that overall this adaptation appears positively selected for in a tropical region to help with thermoregulation and/or camouflage, suggests this subspecies could have other unique adaptations that are less visible than melanism.
Threats Information
Poaching for the illegal wildlife trade is likely to be the greatest factor contributing to the decline of the Indochinese Leopard. Leopard body parts, particularly bones and meat, can be used in traditional Asian medicine, and other Leopard parts, such as teeth and skins, can be sold as luxury items (Oswell 2010, Raza et al. 2012). Therefore, Leopard is targeted by poachers, particularly when Tiger numbers are low. A snaring crisis is occurring throughout Southeast Asia, which is driving severe declines in many species, even within protected areas (Gray et al. 2017, 2018). The primary reason for snaring is to acquire wild meat for the commercial bushmeat trade (Ripple et al. 2016), which often targets common ungulate species such as Wild Pig (Sus scrofa) and muntjacs (Muntiacus spp.). However, snares are unselective and generate substantial by-catch, resulting in the capture of non-target species (Ripple et al. 2016), including Leopard. The widespread intensive snaring for the commercial bushmeat trade probably is causing most of the current human-driven mortality of Leopard. Poaching, either direct or as by-catch, is likely to have led to the disappearance of this subspecies from broad areas of otherwise suitable habitat in Southeast Asia.
Other potential factors contributing to the recent Leopard decline in Southeast Asia and southeastern China are habitat destruction, which facilitates poaching and prey declines, and possibly disease. Habitat loss and fragmentation are probably nowadays only indirect threats to the Leopard in most areas of Southeast Asia, because these factors are closely associated with high levels of human disturbance and poaching. For example, one of the precursors of deforestation in the region is road development, which alone has been shown to increase hunting pressure on mammals (Clements et al. 2014). The deforestation rate in Southeast Asia has been one the highest of all tropical regions, with much of it inside protected areas (Heino et al. 2015), and deforestation rates were still accelerating as of 2010 (Sodhi et al. 2010, Miettinen et al. 2011, Kim et al. 2015). The primary drivers of deforestation in the region are land conversion for plantations (Miettinen et al. 2011, Wilcove et al. 2013) and croplands (Carter et al. 2017, Zeng et al. 2018). For example, the area of primary or secondary forests combined decreased in all Southeast Asian countries from 2000 to 2010, most of which was because of conversion to oil palm and rubber plantations, as the price of these commodities increased 130% and 333%, respectively, during the same period (Wilcove et al. 2013). Because less than 10% of Southeast Asian forests are under some form of protection, and prices of luxury wood, palm oil, and rubber are expected to increase, habitat loss in the region is expected to continue (Sodhi et al. 2010), and thus is likely to have increasingly negative indirect impacts on Leopard populations. In addition, Southeast Asia is a densely populated and rapidly developing region, thus human settlement encroachment and expanding agricultural lands (Carter et al. 2017, Zeng et al. 2018) also are threats to Leopard. Consequently, even if snaring within protected areas was to be suppressed, habitat loss and fragmentation could become a problem for the already small and isolated populations of Leopard.
Prey depletion, while unlikely to have driven the range collapse of the Leopard given its generalist and opportunistic nature (Hayward et al. 2006, Rostro-García et al. 2018), might be a factor that hinders Leopard recovery. Throughout Southeast Asia and southeastern China, populations of non-human primates and large ungulates, typical prey of Leopard in the region (Rabinowitz 1989, Grassman 1999, Rostro-García et al. 2018), are well below carrying capacity because of overhunting by humans, even within protected areas (Johnson et al. 2006, Steinmetz et al. 2010, Kawanishi et al. 2013, Hla Naing et al. 2015). Thus, even in the (at present, hypothetical) absence of poaching of the Indochinese Leopard, the subspecies might not survive competition with humans if its prey base continues to be depleted by overhunting.
Disease, especially canine distemper virus (CDV), might be another factor negatively affecting Leopard populations in some areas of the region. Although not originally thought to be common in cat species, CDV outbreaks have increasingly been shown to devastate local Panthera populations during the past 20 years (Roelke-Parker et al. 1996, Gilbert et al. 2015). The CDV has been confirmed in wild Amur Leopard (P. pardus orientalis, Sulikhan et al. 2018), and might increase extinction rates in small isolated Leopard populations, similar to that shown for Tiger (Gilbert et al. 2014). Importantly, CDV outbreaks in Panthera populations typically originate in local village dogs (Roelke-Parker et al. 1996), thus prohibition of dogs from protected areas in Southeast Asia might be necessary to prevent the transmission of diseases. However, more information is needed on the prevalence of CDV in Indochinese Leopard, and the potential impact this disease might have on small Leopard populations.
In contrast to other Leopard subspecies, conflict with humans is not a major threat to Indochinese Leopard. Attacks on livestock or humans are rarely reported in the region, presumably because densities of Indochinese Leopard are too low to cause significant or widespread conflict. In contrast to Africa, legal trophy hunting does not occur in Southeast Asia, thus this factor is not a threat to Indochinese Leopard.
Use and Trade Information
The Indochinese Leopard is killed illegally for the wildlife trade in Southeast Asia and southeastern China for its body parts, particularly bones and meat, which are used in traditional Asian medicine (Oswell 2010, Raza et al. 2012). Other Leopard parts, such as teeth and skins, are sold as amulets or decorative items. Leopard was the most frequently recorded species in a recent investigation about the trade of big cats in Myanmar and Thailand, with a minimum of 167 individuals recorded in trade in a period of less than 10 years (Oswell 2010). The two main destinations for Leopard parts in Southeast Asia appear to be China and Viet Nam (Rostro-García et al. 2016), although constant trade to Korea and Taiwan also has been reported (Oswell 2010). However, more information is needed about the demand for and destination of Leopard parts in Southeast Asia and China, so that governments can plan more efficient law enforcement operations and non-governmental organizations can initiate effective campaigns orientated towards reducing demand.
Conservation Actions Information
The Leopard is included in CITES Appendix I and in CMS Appendix II. The Leopard is legally protected in China and all countries in Southeast Asia. However, regular enforcement of national laws and patrolling strategies within protected areas are insufficient to provide effective protection of Indochinese Leopard throughout most of the remaining range. For example, in Nam Et – Phou Louey National Protected Area, northern Lao PDR, an increase in funding for enforcement resulted in an increase of days patrolled over a 7-year period, which positively affected gun confiscations and arrest of poachers, but it ultimately failed to prevent the extirpation of Tiger and Leopard because the proliferation of snares was not stopped (Johnson et al. 2016). The development of a systematic, intensified, and effective enforcement regime helped maintain Tiger numbers in Huai Kha Kaeng (Duangchantrasiri et al. 2016). This enforcement strategy is likely to benefit the Leopard as well, therefore similar enforcement strategies are recommended for other protected areas in Southeast Asia and southeastern China where the Indochinese Leopard still occurs. In general, a broad array of actions is required to stem the illegal wildlife trade, including increasing the number of rangers and anti-poaching units, ensuring effective deterrents, coinciding with proactive enforcement, and increases in patrols and check-points to prevent poachers from entering the protected areas. Importantly, given the snaring crisis occurring throughout Southeast Asia, enforcement regimes must address snare removal and prevention, which ultimately means engaging with communities that are the source of the snaring. Likewise, transboundary collaborations among relevant bodies need to be improved to reduce illegal wildlife trade and enhance Leopard conservation (Farhadinia et al. 2020).
Even if poaching is suppressed, fragmentation of Leopard populations could remain a problem. Many of the protected areas that still harbour Indochinese Leopard are isolated, which might hinder the maintenance of genetically viable populations (Kenney et al. 2014). Therefore, to ensure the survival of a viable Leopard metapopulation in the long term, the connectivity of subpopulations must be secured through establishing or maintaining corridors (Kenney et al. 2014). Other conservation actions needed to recover Leopard populations in Southeast Asia and southeastern China should include the conservation and recovery of the main prey species, and the prohibition of dogs from protected areas, to prevent the transmission of CDV and other diseases. Community outreach has been shown to be effective in reducing poaching and increasing prey populations inside Kuiburi National Park, western Thailand (Steinmetz et al. 2014), thus similar programmes should be implemented in other comparable protected areas throughout the region. Overall, education campaigns also are necessary to reduce demand for bushmeat and wildlife parts at the provincial, national, and regional levels (Gray et al. 2018).
Despite the precarious state of the Indochinese Leopard across its range, there are no conservation measures or monitoring programmes specifically focused on this subspecies, except for the long-term monitoring of the Leopard population in eastern Cambodia (WildCRU, Panthera, WWF Cambodia, and Ministry of Environment), and Taman Negara National Park/Kenyir Wildlife Corridor in Malaysia (Rimba, Panthera, Woodland Park Zoo, and DWNP). From 2015 to 2018, Panthera established a Southeast Asia section for their Leopard Program with the goal of establishing long-term monitoring sites in key populations throughout Southeast Asia.
Finally, we recommend the development of a coordinated captive breeding programme for the Indochinese Leopard among zoos in Southeast Asia. Although the total number in captivity is unknown, Indochinese Leopard occurs in many zoos throughout Southeast Asia, including Cambodia, Lao PDR, Thailand, Malaysia, Myanmar, Singapore, and Viet Nam (J. Kamler pers. obs.). However, there is no coordinated captive breeding programme for the Indochinese Leopard. Such a programme is necessary to preserve the genetic integrity of captive Indochinese Leopard, which ultimately may be the source of any potential reintroductions in the future.
