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Distribution map of wild Amur tiger subpopulations, including locations where samples were collected for this study (black dots). N = number of individuals.
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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 as a result of genotyping 256 feces, 7 hair and 11 blood samples collected within southern, central, and northern Sikhote-Alin, as well as Southwest Primorye. Analysis of nucle...
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In fall 2015 researchers from Beijing Normal University BNU China and Land of the Leopard National Park LLNP in the Russian Far East signed a collaborative agreement for transboundary cooperation in surveys and research of the Amur tiger Pan-thera tigris altaica and Amur leopard Panthera pardus orientalis. During this meeting , camera trap database...
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... Although the pack social structure of wolves may result in a higher likelihood of inbreeding compared to the solitary lifestyle of tigers, now this similar situation of the small and isolated population once more occurs in the population of Amur tiger (Panthera tigris altaica). Undoubtedly, there is an urgent need to investigate the degree of inbreeding within the population in order to scientifically implement rescue measures and alleviate the situation 32,33 . ...
... At the same time, 750 individuals in Russia are divided into two distinct subpopulations; the smaller population is located in Southwest Primorye, geographically adjacent to the Laoyeling landscape, which constitutes the major tiger range in China 32,37 . The gene flow between this isolated population and the larger population in Sikhote-Alin Mountains was obstructed by the exacerbation of urbanization, which included the construction of roads, agricultural lands, and small business complexes 33,38 . Adequate surveys and protection of this small isolated cross-border population, which is from Laoyeling and Southwest Primorye, will help to devise the implementation of conservation strategies that will aid the expansion of the large tiger population from Russia to China to address the environmental carrying capacity burden of the concentrated tiger population in Sikhote-Alin Mountains while ensuring the steady increase of the tiger population in China and furthering the spread to the other three forested landscapes. ...
... Russia currently has the world's largest population of wild Amur tigers, 95% of which are found in the Sikhote-Alin mountain range, and a smaller percentage are found in the Southwestern Primorsky region of Russia, which is connected to the core distribution area of Amur tigers in China 32 . Molecular genetic analysis of individuals from each region in Russia in recent years revealed that rapid urbanization has led to difficulties in genetic flow between the two populations in Russia 33 . What's more, small and isolated populations can present a high risk of continued population decline www.nature.com/scientificreports/ ...
The Amur tiger is currently confronted with challenges of anthropogenic development, leading to its population becoming fragmented into two geographically isolated groups: smaller and larger ones. Small and isolated populations frequently face a greater extinction risk, yet the small tiger population’s genetic status and survival potential have not been assessed. Here, a total of 210 samples of suspected Amur tiger feces were collected from this small population, and the genetic background and population survival potentials were assessed by using 14 microsatellite loci. Our results demonstrated that the mean number of alleles in all loci was 3.7 and expected heterozygosity was 0.6, indicating a comparatively lower level of population genetic diversity compared to previously reported studies on other subspecies. The genetic estimates of effective population size (Ne) and the Ne/N ratio were merely 7.6 and 0.152, respectively, representing lower values in comparison to the Amur tiger population in Sikhote-Alin (the larger group). However, multiple methods have indicated the possibility of genetic divergence within our isolated population under study. Meanwhile, the maximum kinship recorded was 0.441, and the mean inbreeding coefficient stood at 0.0868, both of which are higher than those observed in other endangered species, such as the African lion and the grey wolf. Additionally, we have identified a significant risk of future extinction if the lethal equivalents were to reach 6.26, which is higher than that of other large carnivores. Further, our simulation results indicated that an increase in the number of breeding females would enhance the prospects of this population. In summary, our findings provide a critical theoretical basis for further bailout strategies concerning Amur tigers.
... Development of territories, destruction of natural habitats or their fragmentation, associated, for example, with the destruction of forests or the construction of highways, impede the free movement of animals (Goosem, 2007;Naidenko et al., 2021) and, consequently, gene flow (McManus et al., 2014;Schlaepfer et al., 2018). Isolated groups of animals tend to have reduced genetic diversity (Henry et al., 2009;Sorokin et al., 2016), which can lead to reduced immune resistance (Reid et al., 2007;Cartwright et al., 2011), a decrease in reproductive success (Hedrick and Fredrickson, 2010;Erofeeva et al., 2022), slowing down of the development of young (Ralls et al., 1988;Erofeeva et al., 2020), and an increased risk of diseases (Coltman et al., 1999;Spielman et al., 2004). These changes are most significant in regions where anthropogenic impacts on nature are greatest due to the high density of human presence (Goosem, 2007). ...
... Yellow arrow represents potential important ecological corridors for tigers between small and large populations. uous genetic exchange between Changbai-Primorye and the Sikhote-Alin population, increasing the risk of inbreeding depression in the Changbai-Primorye population (Henry et al. 2009;Sorokin et al. 2016). ...
... A true barrier now exists due to continuing development along the Razdolnaya River basin, which prevents movements of tigers between the Changbai landscape and the southern Sikhote-Alin landscape; the populations show clear genetic differentiation (Sorokin et al. 2016). Furthermore, a recent study reported poor health status for the Changbai-Primorye population as well as 50% of individual relationships were cousins or half-sibs (Ning et al. 2022). ...
The continuation of the isolated Amur tiger (Panthera tigris altaica) population living on the China-Russia border is facing serious challenges due to factors such as its small size (including 38 individuals) and canine distemper virus (CDV). To assess options to reduce the impact of these negative factors, we use a population viability analysis (PVA) metamodel, which consists of a traditional individual-based demographic model linked to an epidemiological model, to assess options for controlling the impact of negative factors through domestic dog management in protected areas, increasing connectivity to the neighboring large population (including more than 400 individuals) and habitat expansion. Without intervention, under inbreeding depression of 3.14, 6.29 and 12.26 lethal equivalents, our metamodel predicted the extinction within 100 years is 64.4%, 90.6% and 99.8%, respectively. In addition, the simulation results showed that dog management or habitat expansion independently will not ensure tiger population viability for the next 100 years, and connectivity to the neighboring population would only keep the population size from rapidly declining. However, when the above three conservation scenarios are combined, even at the highest level of 12.26 lethal equivalents inbreeding depression, population size will not decline, the probability of extinction will be < 5.8%. Our findings highlight that protecting the Amur tiger necessitates a multifaceted synergistic effort. Our key management recommendations for this population underline the importance of reducing CDV threats and expanding tiger occupancy to its former range in China, but re-establishing habitat connectivity to the neighboring population is an important long-term objective. This article is protected by copyright. All rights reserved.
... Yellow arrow represents potential important ecological corridors for tigers between small and large populations. uous genetic exchange between Changbai-Primorye and the Sikhote-Alin population, increasing the risk of inbreeding depression in the Changbai-Primorye population (Henry et al. 2009;Sorokin et al. 2016). ...
... A true barrier now exists due to continuing development along the Razdolnaya River basin, which prevents movements of tigers between the Changbai landscape and the southern Sikhote-Alin landscape; the populations show clear genetic differentiation (Sorokin et al. 2016). Furthermore, a recent study reported poor health status for the Changbai-Primorye population as well as 50% of individual relationships were cousins or half-sibs (Ning et al. 2022). ...
Background & Aim: The tiger (Panthera tigris) may be the most charismatic and well-recognized flagship species in the world. As an ecological umbrella species and apex predator, the species symbolizes the well-being of the forest ecosystem. Tigers have lost 93% of their historical range and are experiencing rapid population declines. To enact effective conservation, it is important to understand the ecology and natural history of this globally endangered species. In this paper, we review previous articles related to tiger ecology and conservation research, summarizing the population dynamics and major conservation challenges in Asia in order to outline the actions required to conserve tigers and their ecosystems. Review Results: We found that, while overall research about tigers was increasing, efforts focused primarily on the subspecies with the most remaining range (e.g., P. t. tigris and P. t. altaica) and neglected subspecies requiring urgent attention. Tiger population has increased over the past decade, with estimates increasing from 3,200 to 4,500 during 2010–2021. However, stressors such as habitat fragmentation and loss, hunting of tigers and their prey, illegal trade, and human-tiger conflicts have isolated wild tigers in small populations across their ancestral range. Isolation, small territories, and disease further threaten the extant subspecies. Perspectives: We suggest that establishing a long-term monitoring network is critical for the conservation of tigers. To achieve the goal of a large tiger meta-population across Asia we recommend extensive land use planning, restoring native ungulates, reducing anthropogenic disturbances, improving connectivity of tiger habitats, controlling disease, and extensive cooperation across territories. In landscapes lacking breeding females, we also recommend reintroduction of tigers as a means of increasing recovery speeds.
... In China, the wild Amur tiger population increased from a total of 12-16 individuals in 2000 to 26 individuals in one of the primary core areas assessed between 2012 and 2014 (Wang et al., 2016b). Although the number of Amur tigers and the size of suitable habitat is recovering rapidly in China, severe isolation of habitat patches prevents genetic communication between populations and low levels of genetic diversity have been reported in both China and Russia (Henry et al., 2009;Sorokin et al., 2016;Ning et al., 2019). Considering that the current global population of this subspecies has evolved from only a handful of individuals, the issue of Amur tiger inbreeding and its potential effects on health and hence continued recovery in the wild is an essential area of research and understanding. ...
Inbreeding more likely occurs in small, isolated and endangered populations, and may influence the sustainable survival of a population. As the Amur tiger Panthera tigris altaica population in China experienced a severe decline in the 1990s, the recovering population may be prone to inbreeding and its potential impacts on population health. However, the inbreeding status has not been evaluated and relationships with health remain poorly understood in wild animals. Based on the genetic samples collected from the main Amur tiger habitats in China, this study analyzed the population inbreeding level, major histocompatibility complex polymorphism, parasitic infections and gut microbial structures and functions, and then explored the influence of inbreeding on these traits. Our results indicated that more than 50% of individual relationships were in cousin or half sibs, and 22.73% of individuals had moderate or high inbreeding coefficients. There was a significant positive correlation between the inbreeding level of an individual and the Toxocara cati parasitic load. Gut microbiota community structure and function were also impacted by inbreeding intensity. In conclusion, results indicate that the Amur tiger population in China has reached a moderate level of inbreeding and that there are direct interactions between inbreeding intensity and parasitic load and gut microbiota. This study thus provides an early warning on the Amur tiger population health and should prompt the construction of national and international ecological corridors and/or the re‐introduction of new individuals to relieve the evident inbreeding pressure.
... Each of these scientific units uses a complex of methods. Among them are modern remote (GPS satellite collars, camera traps) and non-invasive methods (analysis of DNA in excrement, hormone metabolites, prey residues, helminths) as well as traditional field methods (measurement of footprints, snow tracking) (Rozhnov et al., 2009(Rozhnov et al., , 2010a(Rozhnov et al., , 2011a(Rozhnov et al., , 2011bNaidenko et al., 2010Naidenko et al., , 2011Naidenko et al., , 2018Naidenko et al., , 2019Sorokin et al., 2010Sorokin et al., , 2016Hernandez-Blanco et al., 2010Goncharuk et al., 2012). These methods have minimal influence on the animals' life and least possible damage to their health; their combinations and effectiveness have been summarized, described and discussed in detail in two monographs (Rozhnov et al., 2018a. ...
... tigers/100 km 2 (Wang et al., 2018). Tiger abundance on the Russian side appears to also be low (Wang et al., 2015), but the population is linked (within Russia) through dispersal to a much larger Russian source population (in Sikhote-Alin Reserve), where the density is nearly 1/100 km 2 (Miquelle et al., 2015;Sorokin et al., 2016). Thus, tiger density in the Chinese recovery site remains 3.7 times lower than in the source site, despite extensive habitat on the Chinese side and over 10 years of intensive management (snare removal, food supplementation, prey augmentation, patrolling and outreach, and monitoring). ...
Landscape‐scale strategies for conserving wild tigers emphasize the role of core breeding populations (source sites) to replenish surrounding areas which have lost tigers. In Southeast Asia, a few potential source sites remain, particularly Huai Kha Khaeng Wildlife Sanctuary, Thailand (HKK). We investigated tiger density in two reserves (Mae Wong, Khlong Lan: MWKL) adjacent to HKK where tigers and their prey were scarce due to historic poaching but current management offered effective protection. Camera trapping revealed 10 adult tigers (four males, six females), at least two of which had immigrated from HKK. Spatially explicit tiger density was 0.359 tigers/100 km2, 5.6 times lower than HKK. The population was breeding, with six cubs observed. Tiger movements (measured by σ, the spatial scale parameter) were twice as extensive in MWKL as in HKK, indicative of prey scarcity in MWKL. The disparity in density between MWKL and HKK reveals that tiger recovery is a slow process when prey are scarce, even when recovery areas are apparently well‐managed and connected to a source site. We review source‐recovery dynamics of tigers in other sites in Asia and find that low prey impedes landscape‐scale recoveries elsewhere as well. Landscape‐scale recovery of wild tigers is impeded by prey depletion, even when recovery areas are connected to a source population.
... The Sikhote-Alin grouping is the most significant in terms of area size and number (up to 80−90% of the present population). Henry et al. (2009), consider that the grouping of Southwestern Primorye is isolated, while P.A. Sorokin et al. (2016) showed that there exist rare migrations of tigers across the Razdolnaya River, and therefore there is an exchange between the two subpopulations. ...
In 2011-2013, we surveyed the population structure, spatial distribution and the number of tigers in Southwestern Primorye (about 5000 km 2). The total number of tigers, according to winter route census, DNA analysis and camera trapping was estimated at 24-25 adults and 6-7 cubs, belonging to four different litters. The location of tigers is mainly confined to areas difficult to access for people, and with a high density of ungulates. Tigers concentrated in the habitat strip bordering China, mainly comprising the 'Land of the Leopard' National Park. A few tiger tracks were recorded outside of protected areas and on hunting tenures. Current methods for estimating tiger numbers needs critical reflection. Winter census by tracks in the snow is often largely influenced by subjectivity. The main reason for this is the large number of surveyors of various degrees of qualification and as a result the conflicting interpretation of track identification. In our opinion, the most objective results are obtained from a consistent survey of the territory by a limited number of specialists and daily adjustments of collected materials. Precise and informative methods for determining the number and the structure of tiger populations are DNA analysis of biological samples combined with camera trap census. However, a number of significant drawbacks limits their widespread use: this method is labor-intensive and results in high project costs. In addition, weather conditions can greatly affect the preservation of DNA in the samples. There is a need to organize additional survey routes for installing camera traps and detecting of biological samples in order to register the tigresses with young, as they are behavior is often distinguished by a more secretive lifestyle. As a rule, female tigers with young avoid the main movement routes of adult tigers. These methods are expedient only in the smaller survey plots of model areas.
... The difficulties (larger or smaller) in animals' movements lead to the fragmentation of populations and animal groups (Vos, Chardon, 1998;Santos, Tabarelli, 2002;Rhodes et al., 2014) with potential impact on their viability (Mumme et al., 2000) and restriction of the gene flow between fragmented populations (Riley et al., 2006;Holderegger, Di Giulio, 2010), including preventing the dispersion of young animals from the natal habitat (Kramer-Schadt et al., 2004;Henry et al., 2009;Sorokin et al., 2016). This can lead to an increase in the probability of closely related mating, leading in some cases to inbreeding (Keyghobadi, 2007). ...
... This highway has become an additional barrier for animals living to the west and east of this highway and separated the range of the Far Eastern leopards from its former range in the middle of XX century (Lewis et al., 2020;Strategy, 2013). For Amur tigers, it was shown that tiger groups in southwestern Primorye and the main part of the range are significantly genetically different from each other, which is explained by serious difficulties animals have with crossing the highway and floodplain of the Razdolnaya River (Henry et al., 2009;Sorokin et al., 2016). It is probable that the new highway may separate the populations of ungulates and other carnivores leading to the genetic differences/losses in subpopulations. ...
... Comm). The subpopulations of the Amur tiger in southwestern Primorye and in the main part of the range (west and east of the highway, respectively), differ genetically from each other (Henry et al., 2009;Sorokin et al., 2016). We did not register the two species of bears that inhabit this region, although they should have been active during at least a part of our study period (November, March-April). ...
The Russian Far East is a unique location that may be considered a hot spot of biodiversity in Russia. In 2010, a new illuminated highway for high-speed traffic was built on its territory. The aim of this study was to evaluate the impact of this highway on the distribution and activity of various mammalian species. We set up camera traps in five lines near the road and obtained photos of 1372 passes of various animals. In total, 15 species of wild mammals were captured by camera traps. Animals preferred to stay far away from the road. This highway became a serious barrier separating the local populations of ungulates and carnivores. Only domestic animals and Amur wild cat used the underpasses more often than other areas. The distance from the road did not affect the daily activity of the mammals.
... Secondly, tigers of the eastern Sikhote-Alin macro slope are characterized by the absence 13 or low infection rate with oriental lung fluke (Paragonimus westermani) 35 . Nevertheless, genetically, tigers of different Sikhote-Alin macro slopes represent one population, but they differ from tigers of the southwestern Primorye 36 . ...
Being a global pollutant, mercury can originate from both natural as well as anthropogenic sources. Coastal marine atmospheric fog is considered a potential source of ocean-derived monomethylmercury (MMHg) to coastal terrestrial ecosystems. However, the ratio between mercury appearing through natural processes and that from the results of human activity is unclear. We assumed that the total mercury content in the fur of tigers would differ depending on the distance from the sea. Here we show that the average mercury content in tigers from the coast (0.435 ± 0.062 mg kg ⁻¹ ) is significantly different from tigers from the inland area (0.239 ± 0.075 mg kg ⁻¹ ), (p = 0.02). We found that the content of mercury in the fur of tigers is largely dependent of natural processes rather than human activity. We assume that the levels of mercury in coastal ecosystems in the south of the Russian Far East reflect the position of the region relative to the deep faults of the East Pacific Platform. Obtained data indicate that environmental risks associated with mercury pollution currently exist, but do not pose a serious threat to Siberian tigers.
