Canine distemper virus (CDV) has recently emerged as an extinction threat for the endangered Amur tiger (Panthera tigris altaica). CDV is vaccine-preventable, and control strategies could require vaccination of domestic dogs and/or wildlife populations. However, vaccination of endangered wildlife remains controversial, which has led to a focus on interventions in domestic dogs, often assumed to be the source of infection. Effective decision making requires an understanding of the true reservoir dynamics, which poses substantial challenges in remote areas with diverse host communities. We carried out serological, demographic, and phylogenetic studies of dog and wildlife populations in the Russian Far East to show that a number of wildlife species are more important than dogs, both in maintaining CDV and as sources of infection for tigers. Critically, therefore, because CDV circulates among multiple wildlife sources, dog vaccination alone would not be effective at protecting tigers. We show, however, that low-coverage vaccination of tigers themselves is feasible and would produce substantive reductions in extinction risks. Vaccination of endangered wildlife provides a valuable component of conservation strategies for endangered species.

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 critically endangered population of Far Eastern leopards ( Panthera pardus orientalis) may number as few as 60 individuals and is at risk from stochastic processes such as infectious disease. During May 2015, a case of canine distemper virus (CDV) was diagnosed in a wild leopard exhibiting severe neurologic disease in the Russian territory of Primorskii Krai. Amplified sequences of the CDV hemagglutinin gene and phosphoprotein gene aligned within the Arctic-like clade of CDV, which includes viruses from elsewhere in Russia, China, Europe, and North America. Histologic examination of cerebral tissue revealed perivascular lymphoid cuffing and demyelination of the white matter consistent with CDV infection. Neutralizing antibodies against CDV were detected in archived serum from two wild Far Eastern leopards sampled during 1993-94, confirming previous exposure in the population. This leopard population is likely too small to maintain circulation of CDV, suggesting that infections arise from spillover from more-abundant domestic or wild carnivore reservoirs. Increasing the population size and establishment of additional populations of leopards would be important steps toward securing the future of this subspecies and reducing the risk posed by future outbreaks of CDV or other infectious diseases.

Large carnivores have extensive spatial requirements, with ranges that often span geopolitical borders. Consequently, management of transboundary populations is subject to several political jurisdictions, often with heterogeneity in conservation challenges. In continental Asia there are four threatened leopard subspecies with transboundary populations spanning 23 countries: the Persian Panthera pardus saxicolor, Indochinese P. pardus delacouri, Arabian P. pardus nimr and Amur P. pardus orientalis leopards. We reviewed the status of these subspecies and examined the challenges to, and opportunities for, their conservation. The Amur and Indochinese leopards have the majority (58–100%) of their remaining range in borderlands, and the Persian and Arabian leopards have 23–26% of their remaining ranges in borderlands. Overall, in 18 of 23 countries the majority of the remaining leopard range is in borderlands, and thus in most countries conservation of these subspecies is dependent on transboundary collaboration. However, we found only two transboundary initiatives for Asian leopards. Overall, we highlighted three key transboundary landscapes in regions that are of high importance for the survival of these subspecies. Recent listing of the leopard in the Bonn Convention on the Conservation of Migratory Species of Wild Animals is important, but more international collaboration is needed to conserve these subspecies. We provide a spatial framework with which range countries and international agencies could establish transboundary cooperation for conserving threatened leopards in Asia.

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.