Amur Tiger Panthera Tigris Altaica Research Articles

Inbreeding status and implications for Amur tigers

AbstractInbreeding 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.

Spatiotemporal patterns of Amur leopards in northeast China: Influence of tigers, prey, and humans

The Amur leopard Panthera pardus orientalis is one of the most endangered cat subspecies in the world. The rare leopard is sympatric with Amur tiger Panthera tigris altaica and their prey in human dominated landscape. To conserve the felid species, it is important to understand the activity patterns of Amur leopards, including its interactions with Amur tigers, prey, and human activities. We used a data set from 163 camera traps to quantify the spatial-temporal overlap between Amur leopards, Amur tigers, prey species, and human disturbances (e.g., humans presence on foot, vehicles, domestic dogs, and cattle grazing) from January to December 2013 in the Hunchun Nature Reserve, NE China. Our results indicated that leopards were more active in daytime and twilight; the seasonal spatial-temporal overlaps between leopards and tigers were lower than that between leopards and their prey species. Human activities and cattle grazing could influence the spatial distribution and activity patterns of the leopards, and therefore, the conservation actions should focus on reduction of human disturbances to minimize the impacts to Amur leopard activity patterns.

Living on the edge: Opportunities for Amur tiger recovery in China

Sporadic sightings of the endangered Amur tiger Panthera tigris altaica along the China-Russia border during the late 1990s sparked efforts to expand this subspecies distribution and abundance by restoring potentially suitable habitats in the Changbai Mountains. To guide science-based recovery efforts and provide a baseline for future monitoring of this border population, empirical, quantitative information is needed on what resources and management practices promote or limit the occurrence of tigers in the region. We established a large-scale field camera-trapping network to estimate tiger density, survival and recruitment in the Hunchun Nature Reserve and the surrounding area using an open population spatially explicit capture-recapture model. We then fitted an occupancy model that accounted for detectability and spatial autocorrelation to assess the relative influence of habitat, major prey, disturbance and management on tiger habitat use patterns. Our results show that the ranges of most tigers abut the border with Russia. Tiger densities ranged between 0.20 and 0.27individuals/100km2 over the study area; in the Hunchun Nature Reserve, the tiger density was three times higher than that in the surrounding inland forested area. Tiger occupancy was strongly negatively related to heavy cattle grazing, human settlements and roads and was positively associated with sika deer abundance and vegetation cover. These findings can help to identify the drivers of tiger declines and dispersal limits and refine strategies for tiger conservation in the human-dominated transboundary landscape. Progressively alleviating the impacts of cattle and human disturbances on the forest, and simultaneously addressing the economic needs of local communities, should be key priority actions to increase tiger populations. The long-term goal is to expand tiger distribution by improving habitats for large ungulates.

Risks involved in fecal DNA-based genotyping of microsatellite loci in the Amur tiger Panthera tigris altaica: a pilot study

In modern wildlife ecological research, feces is the most common non-invasive source of DNA obtained in the field and polymerase chain reaction (PCR) technology based on microsatellite markers is used to mine genetic information contained within. This is especially the case for endangered species. However, there are risks associated with this genotyping method because of the poor quality of fecal DNA. In this study, we assessed genotyping risk across 12 microsatellite loci commonly used in previous tiger studies using blood and fecal DNA from captive Amur tigers (Panthera tigris altaica). To begin, we developed an index termed the accumulated matching rate of genotypes (R m ) between positive DNA (blood samples) and fecal DNA to explore the correct genotyping probability of a certain microsatellite locus. We found that different microsatellite loci had different genotyping risks and required different PCR amplification protocols. The genotyping errors we detected altered population genetic parameters and potentially impact subsequent analyses. Based on these findings, we recommend that: (1) four loci (E7, Fca094, Pti007 and Pti010) of 12 loci are not suitable for Amur tiger genetic research because of a low R m and difficulty reaching a stable status; (2) the R m of the 12 microsatellite loci plateaued differently, and considering limited budgets, amplification times of some loci could be increased when using fecal samples; and (3) future genetic analysis of wild Amur tigers should be corrected by genotyping error rates (1 − R m ).

Comparison of methods for estimating Amur tiger abundance

The Amur tiger Panthera tigris altaica is endangered throughout its range. Estimating abundance to monitor population trends is needed to judge success of conservation efforts. However, low densities and elusive behavior make precise estimates difficult to achieve. Managers must employ sampling methods that maximize precision while remaining feasible under constraints inherent to areas tigers inhabit. We applied camera trap, hair snare, DNA collection, scent‐matching dog, morphometric track identification and track survey methods and developed a rubric to evaluate their efficacy in estimating tiger abundance in Russia. We conducted sampling over the course of one year in Sikhote‐Alin Biosphere Zapovednik (SABZ). We ranked candidate methods using logistical, statistical and cost criteria to evaluate their efficacy for monitoring tiger numbers. Due to logistical and technical constraints, we relied on data from a parallel study to derive three statistical criteria for the DNA collection method. Camera traps, DNA collection, and track surveys were the only methods with sufficient sample sizes to estimate abundance for each sampling session during which the method was tested. DNA collection and camera traps were promising statistically, though poor‐performing for logistics and cost. Technical improvements in camera trap design since the time of this study may improve the method's statistical and cost performance compared to our evaluation. Conversely, track surveys were most efficient logistically and financially, but poor statistically. Method choice for any given monitoring situation should consider local conditions and the specific objectives of the monitoring program in light of all three criteria — statistical, logistical and cost. Failure in any of these areas can lead to failure of a monitoring program.

Spatial variation in the density and vulnerability of preferred prey in the landscape shape patterns of Amur tiger habitat use

Theoretical and empirical research suggests that carnivore distributions are largely determined by prey availability. Availability depends not only on prey density but also on prey accessibility which is affected, in part, by the configuration of landscape attributes that make prey vulnerable to predation. Exactly how spatial variation in these processes shape patterns of carnivore habitat use at the home range scale remains poorly understood. We examined the influence of prey density (negative binomial resource selection function) and vulnerability (kill site resource selection function), mapped separately for each of three species of primary prey, on habitat use patterns within the home range for Amur tigers Panthera tigris altaica in Far East Russia over 20 winters. We developed spatially‐explicit mixed linear regression models to assess these patterns and found that models with parameters for specific primary prey were more robust than models with composite parameters for all primary prey species. This emphasizes the importance of evaluating predation dynamics at a species‐specific level. We also found that Amur tigers used habitat within the home range where red deer Cervus elaphus and wild boar Sus scrofa were dense. These two species were clearly preferred by tigers accounting for 72% (201 of the 278) of the tiger kills detected. The effect of red deer density however, was modulated by the vulnerability of red deer in the landscape. Amur tigers tended to establish their home ranges on habitat where red deer were most vulnerable to predation, but would use habitat where red deer were dense in the peripheral regions of their home ranges. This suggests that tigers may utilize two separate strategies for acquiring prey. As the configuration of resource patches within the home range influences carnivore survival and reproduction, our analysis has implications for tiger conservation that extend beyond our improved understanding of tiger‐prey ecology.

Does prey density limit Amur tiger Panthera tigris altaica recovery in northeastern China?

A residual population of Amur tigers Panthera tigris altaica probably survives in the eastern Wanda Mountains (EWM) in China, where the main prey species are red deer Cervus elaphus, eastern roe deer Capreolus pygargus and wild boar Sus scrofa ussuricus. We used 53 snow sample plots each containing about 29 km of transects to detect ungulate presence and determined their total density in EWM in 2002 to be 87.9 ± 8.9 kg km−2. We then applied these data to three published models that predict the relationship between tiger density and prey biomass density to obtain three estimates of tiger carrying capacity in EWM. Existing estimates of tiger density suggest that tigers were below carrying capacity estimates. Relationships between prey density and tiger density from 15 studies indicate a threshold prey biomass of 195 kg km−2 (CI: 33‐433), below which a tiger population cannot be sustained. We therefore concluded that the EWM population of tigers is in peril. We compared densities between the years 2002 and 2008 using comparable data and found that the EWM populations of the three ungulate prey species all experienced decreases of 40‐45%, apparently due to intense poaching. This rapid decline in prey density and pervasive threats to tigers and their prey in the EWM demands immediate and effective protection of ungulate and tiger populations from poaching if tigers are to persist and recover.

Specific features of feeding of the Amur tiger Panthera tigris altaica (Carnivora, Felidae) in a densely populated locality (with reference to Bol’shekhekhtsirskii Reserve and its environs)

Specific features of feeding of the Amur tiger (Panthera tigris altaica) in the Bol’shekhekhtsirskii Reserve located in a densely populated locality (15 km to the north of the city of Khabarovsk) have been investigated. For a long time (1992–2000) the diet of tigers consisted 100% of wild animals, although the accessibility of domestic animals, dogs, in particular, was high. From 2000 to 2007, in their feeding, the proportion of dogs increased (up to 47%), and the proportion of wild animals decreased (50.8%). Tigers attacking dogs were physically weakened (broken fangs, wounds, inflicted by humans, diseases). It was shown that even in a densely populated locality, the tiger’s diet includes domestic animals only at exposure to different negative factors.

Why do Amur tigers maintain exclusive home ranges? Relating ungulate seasonal movements to tiger spatial organization in the Russian Far East

AbstractWild, solitary felids demonstrate a variety of spacing patterns, with diversity in spatial organization largely attributed to variations in abundance and distribution of important resources, particularly prey. We examined the relationship between territoriality of female Amur tigers Panthera tigris altaica and seasonal movements of a key prey species, Manchurian red deer Cervus canadensis xanthopygus, in the Russian Far East. We predicted that despite considerable seasonal fluctuations in productivity, red deer density does not change seasonally within tigress home ranges. We analyzed radio‐telemetry data to identify directional movements of deer as an indicator of relative changes in seasonal red deer abundance and distribution, and we looked for seasonal shifts in home ranges of tigresses that could signify tracking of migratory prey. We failed to detect either seasonal shifts in tigress home ranges or significant differences in seasonal prey abundance. Most red deer were sedentary, while those that migrated demonstrated varying directionality of movements. Relatively low average snow depth likely reduced directional migratory tendencies in prey populations. Despite existing theory that might predict high overlap of Amur tiger home ranges, our results suggest that exclusive spacing patterns in this tiger subspecies are at least partly explained by the absence of major spatial and temporal changes in ungulate abundance and distribution. We submit that the assumption that home‐range overlap should increase with increasing home‐range size may require further evaluation in cases such as that of Amur tigers.

Effects of odors on behaviors of captive Amur leopards Panthera pardus orientalis

Abstract Captive environments often fail to resemble the wild environment in respects of limited space, unchanging habitat, lack of stimulus and contingency. Common animal welfare problems which occur in captive animals include low behavioral diversity, abnormal behavior and excessive inactivity. Environmental enrichment, as an effective strategy to tackle these problems and promote mental health of captive animals, has been recognized as an important principal for captive animal management. Among all the enrichment techniques, olfactory enrichment is a simple and effective method for improving the well-being of the olfactory sensitive felids. Behavioral problems were observed in six Amur leopards Panthera pardus orientalis at Beijing Zoological Garden. These were held in the older type exhibits which have now been rebuilt. These behaviors include stereotypic behavior and excessive inactivity caused by the spatially limited enclosures with low levels of stimuli. To determine the effects of predator, prey, and herb odors as potential enrichment materials for captive leopards, we conducted olfactory enrichment experiments for the leopards and tested the effects of nutmeg Myristica fragrans, feces of roe deer Capreolus capreolus and urine of Amur tiger Panthera tigris altaica to test for an increase in behavioral repertoire and activity. Odors provided in this study were also believed to improve the psychological and physiological health of individuals. To standardize the method of presentation the odors were introduced to the enclosures by rubbing or spraying onto a clean towel. Our results show that the selected three odors effectively increased the behavioral diversity. Ten new behavior types were observed in the nutmeg experiment, eight in the feces of roe deer experiment and six in the tiger urine experiment. Among the three odors, cats responded to nutmeg for the longest duration, followed by tiger urine and feces of roe deer. Leopards showed more play behavior in presence of nutmeg while more investigatory behavior in presences of feces of roe deer and tiger urine. Providing novel odors increased the spatial use of the exhibit and the animal’s increased use of the logs, sleeping platforms and bars in the cages. Novel odors also significantly increased the overall activity of the leopards, but the effects were diminished in about three hours.

Translocation of problem Amur tigers Panthera tigris altaica to alleviate tiger-human conflicts

We translocated four Amur tigers Panthera tigris altaica captured after killing domestic animals or attacking people; two were released immediately and two following 162 and 388 days rehabilitation. All were radio-collared and released 150–350 km from their capture site. Two translocations were successful: the tigers caused no conflicts with people, killed wild prey, and survived their first winter, although one was poached after 1.1 year and one slipped its collar after surviving 10 months. In the two translocations that were unsuccessful, both tigers moved to areas of high human activity and were killed by people. At least in some cases, translocation appears to be a viable alternative to killing or removing problem tigers from the wild.

Patterns of genetic variation within a captive population of Amur tigerPanthera tigris altaica

Eight founders and thirty-one descendants were sampled as the Founder group and the Offspring group respectively from a captive population of Amur tigerPanthera tigris altaica Temminck, 1844 for population genetic analysis with RAPD and ISSR markers. Integrated with demographic data during the initial recovery stage, results showed: (1) increasing the population size (N) and the effective population size (N e) greatly retard lose of genetic variation induced mainly by genetic drift and selection; (2) recombination and admixture could cause the Offspring group (5.711%) and the Founder group (10.383%) to hold different linkage disequilibrium (LD); (3) further Ohta’s variance analysis indicated genetic drift (87.3%) and epistatic selection (12.7%) maintained LD in population, whereas GENEDROP analysis supported epistatic selection largely derived from artificial selection of managers; (4) both Tajima’s test and Fu’s test confirmed the statistic neutrality of genetic markers used, moreover the positive value of Tajima’sD (0.090) together with the result that π (25.286) was bigger than ϑ (24.898) revealed the Founder group was admixture population, while the negative Tajima’sD value (−0.053) together with the result that π (23.679) was less than ϑ (23.912) disclosed the Offspring group experienced selective sweep.