Political borders and natural boundaries of wildlife populations seldom coincide, often to the detriment of conservation objectives. Transnational monitoring of endangered carnivores is rare, but is necessary for accurate population monitoring and coordinated conservation policies. We investigate the benefits of collaboratively monitoring the abundance and survival of the critically endangered Amur leopard, which occurs as a single transboundary population across China and Russia. Country-specific results overestimated abundance and were generally less precise compared to integrated monitoring estimates; the global population was similar in both years: 84 (70-108, 95% confidence interval). Uncertainty in country-specific annual survival estimates were approximately twice the integrated estimates of 0.82 (0.69-0.91, 95% confidence limits). This collaborative effort provided a better understanding of Amur leopard population dynamics, represented a first step in building trust, and lead to cooperative agreements to coordinate conservation policies. K E Y W O R D SAmur leopard, camera traps, carnivore, China, mark-recapture, monitoring, Panthera pardus orientalis, Russia, transboundary conservationThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

The paper describes the methodology and preliminary results of a complex camera trap study of the Amur leopard. The main studies were concentrated on protected areas: the Land of the Leopard National Park with its buffer zone and the Kedrovaya Pad' Biosphere Reserve, a total area of 3600 km 2 . The first results of the 2014-2015 survey period are presented. According to spatial capture-recapture analysis at least 57 adult Amur leopards occupied the Russian protected areas with the density of about 0.98 individuals/100 km 2 . The sex ratio (male : female) was 1:1.2. Five breeding females with 11 cubs were registered in 2014 and 9 females with 16 cubs in 2015. The basis was founded for long-term monitoring of and fundamental research on the Amur leopard in the protected areas in Primorsky Krai.

Southwest Primorsky Krai retains the sole remaining population of critically endangered Amur leopards, but and also holds an isolated population of Amur tigers. This small group of tigers plays a key role as a core breeding population for potential Amur tiger recovery in neighboring Jilin and Heilongjiang Provinces of Northeast China. A large scale camera-trap monitoring program initiated by the United Administration of the State Nature Biosphere Reserve Kedrovaya Pad and Land of the Leopard National Park in 2013 provides a more precise means of tracking dynamics of animals' abundance than previous snow-track counts and is to act «early warning system» in a case of dramatic decreases in tiger numbers. Surveys were conducted over three years, beginning in August 2013 and ending in July 2016. During each survey year, we planned to select a survey period of no more than 92 days when no less than 80% of camera-trap stations were active. However, as the camera-trap stations were not simultaneously deployed and checked during the last year (2015)(2016), using the 80% cut point substantially was not feasible, so we lowered the limit to 55%. To estimate detection rates for adults, we used only those animals that were present in a given year both before and after the survey period, with the assumption that if a tiger were present both before and after, most likely it was present during the survey period as well. From the 320 photographic captures obtained over three years we identified 39 adult Amur tigers and 22 cubs. Among them only seven adult individuals (18%) were captured in all three years, while sixteen adult individuals (41%) were captured only in one of the three years; the rest (41%) were captured in two of the three years. Females demonstrate greater fidelity, and a greater likelihood or being present in all three years. Tigers were more frequently captured during the cold season from October to March with the peak numbers recorded in December. However, there were only ten instances in which adult/subadult tigers were photographed both before and after the survey period in all years combined. Of those, in only six instances (60%) tigers also photographed during the survey period, suggesting a relatively low detection probability. However detection of cubs was even lower: twenty-two cubs were photographed during the three years of the study but only three (14%) were photographed during the three survey periods. These results suggest that capture rates of cubs are much lower than those of adults/subadults reaffirming recommendations to not include cubs in formal population abundance estimates.

Small populations of the endangered species are more vulnerable to extinction and hence require periodic genetic monitoring to establish and revisit the conservation strategies. The Amur leopard is critically endangered with about 100 individuals in the wild. In this study, we developed a simple and cost-effective noninvasive genetic monitoring protocol for Amur leopards. Also, we investigated the impact of fecal sample’s age, storage, and collection season on microsatellite genotyping success and data quality. We identified 89 leopard scats out of the 342 fecal samples collected from Land of the Leopard between 2014–2019. Microsatellite genotyping using 12 markers optimized in 3 multiplex PCR reactions reveals presence of at least 24 leopard individuals (18 males and 6 females). There was a significant difference in the success rate of genotyping depending on the time from feces deposition to collection (p = 0.014, Fisher’s exact test), with better genotyping success for samples having <2 weeks of environmental exposure. Amur leopard genetic diversity was found low (Ho− 0.33, HE− 0.35, and NA− 2.57) with no visible population substructure and recent bottleneck signature. Although a historical bottleneck footprint was observed. Mitochondrial DNA diversity was also found low with two haplotypes differing by a point mutation reported in 1,769 bp of investigated sequence covering parts of cytochrome b gene (846 bp), NADH-5 gene (611 bp) and control region (312 bp). We recommend periodic genetic monitoring of wild Amur leopards following the proposed methodology to achieve cost effectiveness and efficiency.

Big cats (Genus: Panthera) are among the most threatened mammal groups of the world, owing to hunting, habitat loss, and illegal transnational trade. Conservation genetic studies and effective curbs on poaching are important for the conservation of these charismatic apex predators. A limited number of microsatellite markers exists for Panthera species and researchers often cross-amplify domestic cat microsatellites to study these species. We conducted data mining of seven Panthera genome sequences to discover microsatellites for conservation genetic studies of four threatened big cat species. A total of 32 polymorphic microsatellite loci were identified in silico and tested with 152 big cats, and were found polymorphic in most of the tested species. We propose a set of 12 novel microsatellite markers for use in conservation genetics and wildlife forensic investigations of big cat species. Cumulatively, these markers have a high discriminatory power of one in a million for unrelated individuals and one in a thousand for siblings. Similar PCR conditions of these markers increase the prospects of achieving efficient multiplex PCR assays. This study is a pioneering attempt to synthesise genome wide microsatellite markers for big cats.