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The automatic individual identification of Amur tigers (Panthera tigris altaica) is important for population monitoring and making effective conservation strategies. Most existing research primarily relies on manual identification, which does not scale well to large datasets. In this paper, the deep convolution neural networks algorithm is constructed to implement the automatic individual identification for large numbers of Amur tiger images. The experimental data were obtained from 40 Amur tigers in Tieling Guaipo Tiger Park, China. The number of images collected from each tiger was approximately 200, and a total of 8277 images were obtained. The experiments were carried out on both the left and right side of body. Our results suggested that the recognition accuracy rate of left and right sides are 90.48% and 93.5%, respectively. The accuracy of our network has achieved the similar level compared to other state of the art networks like LeNet, ResNet34, and ZF_Net. The running time is much shorter than that of other networks. Consequently, this study can provide a new approach on automatic individual identification technology in the case of the Amur tiger.

There have been few reports on the diversity and prevalence of parasitic fauna of the endangered Siberian tiger, which inhabits the territory of the Russian Far East. The present review attempts to summarize the information about the parasitic fauna of wild Siberian tigers, which includes 15 helminths and 3 protozoan species. The most prevalent parasitic species was found to be Toxocara cati, followed by Toxascaris leonina. Another commonly recorded Platyhelminth species is Paragonimus westermani, which causes a lethal infection of the lung parenchyma in Siberian tigers. However, the information about infections by this fluke in the Siberian tigers is scarce, although P. westermani infections pose a serious health hazard to tiger populations. The nematodes Aelurostrongylus abstrusus and Thominx aerophilus are found in Siberian tigers with an occurrence rate of 2.3% and 19%, respectively. The information on the parasitic infestations of captive populations of Siberian tigers is also presented along with the sources of infection and hazards for the wild tiger populations in their natural environment.

A small, isolated Amur tiger population ranges across the southwest Primorskii Krai region in Russia and Hunchun region in China. Many individuals, with "dual nationality," cross the border frequently. Formulating effective conservation strategies requires a clear understanding of tiger food requirements in both countries. While the diets of tigers ranging in Russia is clearly understood, little is known of the tigers' feeding habits in China.. We used scat analysis combined with data on the abundance of 4 prey species to examine Amur tiger diet and prey preferences in Hunchun. We examined 53 tiger scat samples from 2011 to 2016 and found that tigers preyed on 12 species (11 species in winter), 4 of which were domestic animals with 33.58% biomass contribution; this was the first record of Amur tigers eating lynx in this area. Tigers showed a strong preference for wild boar (Jacobs index: +0.849), which were also the most frequently consumed prey, and a strong avoidance of roe deer (Jacobs index: -0.693). On the Russian side, domestic animals (just dog) were rarely found in tiger scat, and tigers did not show strong avoidance of roe deer, but of sika deer. We also found red deer footprints during winter surveys and that tigers ate red deer on the Chinese side, while there was no record of red deer feeding on the Russian side. Reducing or eliminating human disturbance, such as grazing, is essential to recovering tiger prey and habitat in this area and the Sino-Russian joint ungulate annual survey is indispensable for prey estimates of this small, isolated Amur tiger population.

While there are numerous wildlife ecology studies in lowland areas of Nepal, there are no in-depth studies of the hilly Churia habitat even though it comprises 7642 km2 of potential wildlife habitat across the Terai Arc. We investigated tiger, leopard and prey densities across this understudied habitat. Our camera trapping survey covered 536 km2 of Churia and surrounding areas within Chitwan National Park (CNP). We used 161 trapping locations and accumulated 2097 trap-nights in a 60-day survey period during the winter season of 2010-2011. In addition, we walked 136 km over 81 different line transects using distance sampling to estimate prey density. We photographed 31 individual tigers, 28 individual leopards and 25 other mammalian species. Spatial capture-recapture methods resulted in lower density estimates for tigers, ranging from 2.3 to 2.9 tigers per 100 km2 , than for leopards, which ranged from 3.3 to 5.1 leopards per 100 km2 . In addition, leopard densities were higher in the core of the Churia compared to surrounding areas. We estimated 62.7 prey animals per 100 km2 with forest ungulate prey (sambar, chital, barking deer and wild pig), accounting for 47% of the total. Based on prey availability, Churia habitat within CNP could potentially support 5.86 tigers per 100 km2 but our density estimates were lower, perhaps indicating that the tiger population is below carrying capacity. Our results demonstrate that Churia habitat should not be ignored in conservation initiatives, but rather management efforts should focus on reducing human disturbance to support higher predator numbers.

As an apex predator the Amur tiger (Panthera tigris altaica) could play a pivotal role in maintaining the integrity of forest ecosystems in Northeast Asia. Due to habitat loss and harvest over the past century, tigers rapidly declined in China and are now restricted to the Russian Far East and bordering habitat in nearby China. To facilitate restoration of the tiger in its historical range, reliable estimates of population size are essential to assess effectiveness of conservation interventions. Here we used camera trap data collected in Hunchun National Nature Reserve from April to June 2013 and 2014 to estimate tiger density and abundance using both maximum likelihood and Bayesian spatially explicit capture-recapture (SECR) methods. A minimum of 8 individuals were detected in both sample periods and the documentation of marking behavior and reproduction suggests the presence of a resident population. Using Bayesian SECR modeling within the 11 400 km(2) state space, density estimates were 0.33 and 0.40 individuals/100 km(2) in 2013 and 2014, respectively, corresponding to an estimated abundance of 38 and 45 animals for this transboundary Sino-Russian population. In a maximum likelihood framework, we estimated densities of 0.30 and 0.24 individuals/100 km(2) corresponding to abundances of 34 and 27, in 2013 and 2014, respectively. These density estimates are comparable to other published estimates for resident Amur tiger populations in the Russian Far East. This study reveals promising signs of tiger recovery in Northeast China, and demonstrates the importance of connectivity between the Russian and Chinese populations for recovering tigers in Northeast China.

We used molecular genetic analyses to noninvasively identify individual Amur tigers and define subpopulations of tigers in the Russian Far East. We identified 63 individuals after genotyping 256 feces, 7 hair and 11 blood samples collected within southern, central and northern Sikhote-Alin, as well as Southwest Primorye. Analysis of nuclear DNA at 9 microsatellite loci demonstrated greater genetic similarity between animals from southern and northern Sikhote-Alin (some 500 km apart) than between animals from Ussuriskii State Nature Reserve and Southwest Primorye (less than 10 km apart at their nearest point), suggesting that a true barrier exists preventing movements of tigers between Southwest Primorye and the southern Sikhote-Alin Mountains.

Although considerable conservation resources have been committed to develop and use law enforcement monitoring and management tools such as SMART, measures of success are ill-defined and, to date, few reports detail results post-implementation. Here, we present 4 case studies from protected areas with Amur tigers (Panthera tigris altaica) in Russia, in which indicators of success were defined and evaluated at each. The ultimate goal was an increase in tiger numbers to 1 individual/100 km(2) at each site. We predicted that improvements in law enforcement effectiveness would be followed by increases in prey numbers and, subsequently, tiger numbers. We used short-term and long-term indicators of success, including: (i) patrol team effort and effectiveness; (ii) catch per unit effort indicators (to measure reductions in threats); and (iii) changes in target species numbers. In addition to implementing a monitoring system, we focused on improving law enforcement management using an adaptive management process. Over 4 years, we noted clear increases in patrol effort and a partial reduction in threats. Although we did not detect clear trends in ungulate numbers, tiger populations remained stable or increased, suggesting that poaching of tigers may be more limiting than prey depletion. Increased effectiveness is needed before a clear reduction in threats can be noted, and more time is needed before detecting responses in target populations. Nonetheless, delineation of concrete goals and indicators of success provide a means of evaluating progress and weaknesses. Such monitoring should be a central component of law enforcement strategies for protected areas.

Prey availability is one of the principal drivers of tiger distribution and abundance. Therefore, formulating effective conservation strategies requires a clear understanding of tiger diet. We used scat analysis in combination with data on the abundance of several prey species to estimate Amur tiger diet and preference at 3 sites in the Russian Far East. We also examined the effect of pseudoreplication on estimates of tiger diet. We collected 770 scats across the 3 sites. Similar to previous studies, we found that tigers primarily preyed on medium to large ungulates, with wild boar, roe, sika and red deer collectively comprising 86.7% of total biomass consumed on average. According to Jacobs' index, tigers preferred wild boar, and avoided sika deer. Variation in preference indices derived from these scat analyses compared to indices derived from kill data appear to be due to adjustments in biomass intake when sex-age of a killed individual is known: a component missing from scat data. Pseudoreplication (multiple samples collected from a single kill site) also skewed results derived from scat analyses. Scat analysis still appears useful in providing insight into the diets of carnivores when the full spectrum of prey species needs to be identified, or when sample sizes from kill data are not sufficient. When sample sizes of kill data are large (as is now possible with GPS-collared animals), kill data adjusted by sex-age categories probably provides the most accurate estimates of prey biomass composition. Our results provide further confirmation of the centrality of medium ungulates, in particular wild boar, to Amur tiger diet, and suggest that the protection of this group of species is critical to Amur tiger conservation.

The rapid explosion of human populations and the associated development of human-dominated landscapes have drastically reduced and fragmented habitat for tigers (Panthera tigris) and leopards (Panthera pardus) across Asia, resulting in multiple small populations. However, Amur tiger (Panthera tigris altaica) habitat in Russia has remained largely interconnected, except for a break between tigers in southwest Primorye and the southern Sikhote-Alin Mountains. This habitat patch in southwest Primorye also retains the last population of Amur leopards (Panthera pardus orientalis). Genetic differentiation of tigers in southwest Primorye and the Sikhote-Alin Mountains along with survey data suggest that habitat fragmentation is limiting movement of tigers and leopards across the Razdolnaya River basin. We looked at historical and recent survey data on tigers and leopards and mapped existing cover types to examine land-use patterns of both large felids and humans in the development strip along the Razdolnaya River. We then used least-cost distance analyses to identify the most effective potential corridor to retain connectivity for large felids between Land of the Leopard National Park and Ussuriskii Zapovednik (Reserve). We identified a single potential corridor that still exists with a total distance of 62.5 km from Land of the Leopard National Park to Ussuriskii Zapovednik, mostly (93%) through forested habitat. We recommend formal recognition of a Razdolnaya ecological corridor and provide specific recommendations for each of 3 proposed management sections.

A century ago, tigers (Panthera tigris Linnaeus, 1758) were so common in parts of Southeast Asia as to be considered pests, and governments sponsored their killing. Habitat loss and fragmentation, market-driven poaching and loss of prey have since led to the disappearance of Indochinese tigers from most their former range. Despite 15 years of dedicated tiger conservation funding, national estimates of Indochinese tiger subpopulations can at best only be roughly approximated. The future for the subspecies appears grim unless very focused efforts can be applied to stabilize and recover subpopulations. On a regional scale, the 2 proposed subspecies Panthera tigris corbetti and P. tigris jacksoni are effectively managed as separate conservation units. Evaluating where to place conservation efforts should consider the vulnerability (likelihood of extinction) and irreplaceability (likelihood that an area contributes uniquely to regional conservation) of tiger subpopulations. Only 1 site in Thailand supporting200 individuals (Huai Kha Khaeng-Thung Yai) is considered low vulnerability, and is irreplaceable. Five sites in Lao, Thailand and Peninsular Malaysia are medium vulnerability and irreplaceable. Priorities at these 6 sites are to double tiger numbers within 10 years through protection and monitoring. Seven sites in Lao, Thailand and Myanmar are high vulnerability and irreplaceable, and might be recovered if government commitment to tigers, staff capacity and legal frameworks for tiger protection are established. Tigers are extremely vulnerable or even extinct in Cambodia's Eastern Plains and the site is irreplaceable for tigers because it represents the only large (10,000 km(2) ) block of dry forest habitat available in the region. A reintroduction program is the only option to recover tigers there.

Human-tiger (Panthera tigris Linnaeus, 1758) conflicts (HTC), manifested primarily as attacks on people and domestic animals, exacerbate at least 2 major threats to tigers: (i) conflicts often result in mortality or removal of tigers from the wild; and (ii) they result in negative attitudes towards tigers by local people, thereby reducing support for tiger conservation. Although HTC has decreased over the past century, it will likely increase if current and proposed conservation initiatives to double tiger populations are successful. Increased HTC could undermine successful conservation initiatives if proactive steps are not taken to reduce HTC. The present paper provides a review of the impacts of HTC and the measures taken to reduce it in ways that reduce negative impacts on both humans and tigers, and stresses the need for development and implementation of comprehensive plans to reduce HTC.

Poaching as well as loss of habitat and prey are identified as causes of tiger population declines. Although some studies have examined habitat requirements and prey availability, few studies have quantified cause-specific mortality of tigers. We used cumulative incidence functions (CIFs) to quantify cause-specific mortality rates of tigers, expanding and refining earlier studies to assess the potential impact of a newly emerging disease. To quantify changes in tiger mortality over time, we re-examined data first collected by Goodrich et al. (; study period 1: 1992-2004) as well as new telemetry data collected since January 2005 (study period 2: 2005-2012) using a total of 57 tigers (27 males and 30 females) monitored for an average of 747 days (range 26-4718 days). Across the entire study period (1992 to 2012) we found an estimated average annual survival rate of 0.75 for all tigers combined. Poaching was the primary cause of mortality during both study periods, followed by suspected poaching, distemper and natural/unknown causes. Since 2005, poaching mortality has remained relatively constant and, if combined with suspected poaching, may account for a loss of 17-19% of the population each year. Canine distemper virus (CDV) may be an additive form of mortality to the population, currently accounting for an additional 5%. Despite this relatively new source of mortality, poaching remains the main threat to Amur tiger survival and, therefore, population growth.

Anthropogenic impacts are the primary threats to Amur tigers (Panthera tigris altaica) and their habitat. Villagers living in proximity to tigers tend to view them negatively and, often, as a source of revenue on black markets. We aim to reduce human-tiger conflict by working with young students of Ternei County in the heart of tiger habitat in Primorskii Krai (Province). To inform and influence Ternei County's future decision-makers, we developed "Safe Conduct", a year-long education program held in 6 villages, culminating in a multi-school conference. We tested the efficacy of Safe Conduct as a potential model for tiger conservation educational programs. We measured levels of student knowledge about tiger ecology, their attitude towards tigers, and their willingness to engage in tiger conservation activites prior to, immediately after and 6 months following the completion of our program. Results supported the fundamental premise of Safe Conduct that knowledge and attitude towards tigers are correlated. Knowledge of tiger ecology and attitude towards tigers increased by the project's completion; both remained high after 6 months. However, commitment to participation in conservation efforts rose temporarily post-program and then dropped. Results varied by village. We recommend that the reasons for the high performance measures of students in 2 villages be investigated, and that lessons learned be applied to villages that underperformed. Safe Conduct represents a potential model for environmental education programs in Ternei County and elsewhere to educate future generations, to eventually develop a strong commitment to Amur tiger conservation at the community level.

In 2010, the world's tiger (Panthera tigris) range countries agreed to the goal of doubling tiger numbers over 12 years, but whether such an increase is biologically feasible has not been assessed. Long-term monitoring of tigers in Sikhote-Alin Biosphere Zapovednik (SABZ), Russia provided an opportunity to determine growth rates of a recovering population. A 41-year growth phase was followed by a rapid decline in tiger numbers. Annual growth rates during the growth phase averaged 4.6%, beginning near 10% in the earliest years but quickly dropping below 5%. Sex ratio (females per male) mirrored growth rates, declining as population size increased. The rapid decline from 2009 to 2012 appeared to be tied to multiple factors, including poaching, severe winters and disease. Reproductive indicators of this population are similar to those of Bengal tiger populations, suggesting that growth rates may be similar. These results suggest that, first, tiger populations likely in general grow slowly: 3-5% yearly increases are realistic and larger growth rates are likely only when populations are highly depressed, mortality rates are low and prey populations are high relative to numbers of adult females. Second, while more research is needed, it should not be assumed that tiger populations with high prey densities will necessarily grow more quickly than populations with low prey densities. Third, while growth is slow, decline can be rapid. Fourth, because declines can happen so quickly, there is a constant need to monitor populations and be ready to respond with appropriate and timely conservation interventions if tiger populations are to remain secure. Finally, an average annual growth rate across all tiger populations of 6%, required to reach the Global Tiger Initiative's goal of doubling tiger numbers in 12 years, is a noble but unlikely scenario.

Poaching and trans-boundary trafficking of tigers and body parts are threatening the world's last remaining wild tigers. Development of an efficient molecular genetic assay for tracing the origins of confiscated specimens will assist in law enforcement and wildlife forensics for this iconic flagship species. We developed a multiplex genotyping system “tigrisPlex” to simultaneously assess 22 short tandem repeat (STR, or microsatellite) loci and a gender-identifying SRY gene, all amplified in 4 reactions using as little as 1 ng of template DNA. With DNA samples used for between-run calibration, the system generates STR genotypes that are directly compatible with voucher tiger subspecies genetic profiles, hence making it possible to identify subspecies via bi-parentally inherited markers. We applied “tigrisPlex” to 12 confiscated specimens from Russia and identified 6 individuals (3 females and 3 males), each represented by duplicated samples and all designated as Amur tigers (Panthera tigris altaica) with high confidence. This STR multiplex system can serve as an effective and versatile approach for genetic profiling of both wild and captive tigers as well as confiscated tiger products, fulfilling various conservation needs for identifying the origins of tiger samples.

Historical records can provide important evidence of changes in distributions of wildlife species. Here we discuss the distribution of the tiger (Panthera tigris Linnaeus, 1758) over the past 2000 years in China based on 2635 historical records. We also compare tiger distributions outlined in these records with ecosystem type maps. Throughout this time period, tigers maintained a broad distribution across 7 biomes (from forests to deserts). However, in recent decades the range has been significantly condensed. Today, only 2 populations remain, neither of which is independently viable. Tigers have completely disappeared from the temperate broadleaf and mixed forests of central China, a region that was traditionally their most important biome in China. The continued presence of wild tigers in China is highly dependent on significant conservation measures.

Wild tigers are in a critical state with an estimated population decline of more than 95% over the past century. Improving the capacity and effectiveness of law enforcement in reducing poaching of tigers is an immediate priority to secure remaining wild populations in source sites. From 2008–2010, standardized patrol-based law enforcement monitoring (LEM) was established under the Tigers Forever Program across 8 key tiger sites in order to improve and evaluate law enforcement interventions. Patrol-based monitoring has the distinct advantage of providing regular and rapid information on illegal activities and ranger performance, although, until recently, it has received relatively little scrutiny from the conservation community. The present paper outlines a framework for implementation of LEM in tiger source sites using MIST, a computerized management information system for ranger-based data collection. The framework addresses many of the technical, practical and institutional challenges involved in the design, implementation, sustainability and evaluation of LEM. Adoption of such a framework for LEM is a cost-effective strategy to improve the efficiency of law enforcement efforts, to increase the motivation of enforcement staff and to promote the accountability of law enforcement agencies in addressing threats to tigers. When combined with independent, systematic and science-based monitoring of tigers and their prey, LEM has great potential for evaluating the effectiveness of protection-based conservation investments.

Wild tigers are being annihilated. Tiger range countries and their partners met at the 1st Asian Ministerial Conference on Tiger Conservation in January 2010 to mandate the creation of the Global Tiger Recovery Program to double the number of tigers by 2022. Only 3200-3600 wild adult tigers remain, approximately half of the population estimated a decade ago. Tigers now live in only 13 countries, all of which are experiencing severe environmental challenges and degradation from the effects of human population growth, brisk economic expansion, rapid urbanization, massive infrastructure development and climate change. The overarching challenge of tiger conservation, and the conservation of biodiversity generally, is that there is insufficient demand for the survival of wild tigers living in natural landscapes. This allows the criminal activities of poaching wild tigers and their prey and trafficking in tiger derivatives to flourish and tiger landscapes to be diminished. The Global Tiger Recovery Program will support scaling up of practices already proven effective in one or more tiger range countries that need wider policy support, usually resources, and new transnational actions that enhance the effectiveness of individual country actions. The program is built on robust National Tiger Recovery Priorities that are grouped into themes: (i) strengthening policies that protect tigers; (ii) protecting tiger conservation landscapes; (iii) scientific management and monitoring; (iv) engaging communities; (v) cooperative management of international tiger landscapes; (vi) eliminating transnational illegal wildlife trade; (vii) persuading people to stop consuming tiger; (viii) enhancing professional capacity of policy-makers and practitioners; and (ix) developing sustainable, long-term financing mechanisms for tiger and biodiversity conservation.

Over the past half century, wildlife research has relied on technological advances to gain additional insight into the secretive lives of animals. This revolution started in the 1960s with the development of radio telemetry and continues today with the use of Global Positioning System (GPS)-based research techniques. In the present paper we review the history of radio telemetry from its origins with grizzly bears in Yellowstone to its early applications in tiger research and conservation in Asia. We address the different types of data that are available using radio telemetry as opposed to using other research techniques, such as behavioral observations, camera trapping, DNA analysis and scat analysis. In the late 1990s, the rapid development of GPS collar technology revolutionized wildlife research. This new technology has enabled researchers to dramatically improve their ability to gather data on animal movements and ecology. Despite the ecological and conservation benefits of radio telemetry, there have been few telemetry studies of tigers in the wild, and most have been on the Bengal or Amur subspecies. We close with an assessment of the current tiger conservation efforts using GPS technology and discuss how this new information can help to preserve tigers for future generations.

This paper is a review of the history, development and efficacy of using dogs in wildlife studies and considers the use of dogs in the research and conservation of wild tigers (Panthera tigris Linnaeus, 1758). Using scat detection dogs, scent-matching dogs, law enforcement detection dogs and protection dogs are proven methods that can be effectively used on tigers. These methods all take advantage of the dog's extremely evolved sense of smell that allows them to detect animals or animal byproducts (often the focus of tiger studies). Dogs can be trained to communicate this information to their handlers.

With only 5% of the world's wild tigers (Panthera tigris Linnaeus, 1758) remaining since the last century, conservationists urgently need to know whether or not the management strategies currently being employed are effectively protecting these tigers. This knowledge is contingent on the ability to reliably monitor tiger populations, or subsets, over space and time. In the this paper, we focus on the 2 seminal methodologies (camera trap and occupancy surveys) that have enabled the monitoring of tiger populations with greater confidence. Specifically, we: (i) describe their statistical theory and application in the field; (ii) discuss issues associated with their survey designs and state variable modeling; and, (iii) discuss their future directions. These methods have had an unprecedented influence on increasing statistical rigor within tiger surveys and, also, surveys of other carnivore species. Nevertheless, only 2 published camera trap studies have gone beyond single baseline assessments and actually monitored population trends. For low density tiger populations (e.g.