Tiger Density Research Articles

Integration of the landscape of fear concept in grassland management: An experimental study on subtropical monsoon grasslands in Bardia National Park, Nepal.

The 'landscape of fear' concept offers valuable insights into wildlife behaviour, yet its practical integration into habitat management for conservation remains underexplored. In this study, conducted in the subtropical monsoon grasslands of Bardia National Park, Nepal, we aimed to bridge this gap through a multi-year, landscape-scale experimental investigation in Bardia National Park, Nepal. The park has the highest density of tigers (with an estimated density of ~7 individuals per 100 km2) in Nepal, allowing us to understand the effect of habitat management on predation risk and resource availability especially for three cervid species: chital (Axis axis), swamp deer (Rucervus duvaucelii) and hog deer (Axis porcinus). We used plots with varying mowing frequency (0-4 times per year), size (ranging from small: 49 m2 to large: 3600 m2) and artificial fertilisation type (none, phosphorus, nitrogen) to assess the trade-offs between probable predation risk and resources for these cervid species, which constitute primary prey for tigers in Nepal. Our results showed distinct responses of these deer to perceived predation risk within grassland habitats. Notably, these deer exhibited heightened use of larger plots, indicative of a perceived sense of safety, as evidenced by the higher occurrence of pellet groups in the larger plots (mean = 0.1 pellet groups m-2 in 3600 m2 plots vs. 0.07 in 400 m2 and 0.05 in 49 m2 plots). Furthermore, the level of use by the deer was significantly higher in larger plots that received mowing and fertilisation treatments compared to smaller plots subjected to similar treatments. Of particular interest is the observation that chital and swamp deer exhibited greater utilisation of the centre (core) areas within the larger plots (mean = 0.21 pellet groups m-2 at the centre vs. 0.13 at the edge) despite the edge (periphery) also provided attractive resources to these deer. In contrast, hog deer did not display any discernible reaction to the experimental treatments, suggesting potential species-specific variations in response to perceived predation risk arising from management interventions. Our findings emphasise the importance of a sense of security as a primary determinant of habitat selection for medium-sized deer within managed grassland environments. These insights carry practical implications for park managers, providing a nuanced understanding of integrating the 'landscape of fear' into habitat management strategies. This study emphasises that the 'landscape of fear' conceptcan and should be integrated into habitat management to maintain delicate predator-prey dynamics within ecosystems.

Influence of resource gradients and habitat edges on density variation in tiger populations in a multi-use landscape

Spatial heterogeneity in the local densities of terrestrial carnivores is driven by multiple interacting biotic and abiotic factors. Space-use patterns of large carnivores reflect the competing demands of resource selection (e.g., exploitation of habitats with abundant prey) and minimization of risks arising from human interactions. Estimating the relative strength of these drivers is essential to understand spatial variation in densities of large carnivores and there are still key knowledge gaps for many large carnivore populations. To better understand the relative roles of environmental and human drivers of spatial variation in tiger (Panthera tigris) densities, we surveyed a 3000 km2 landscape in North India using camera trap data. Over two years, we photo-captured 92 unique adult tigers. Associating spatial covariates with patterns of detection allowed us to test hypotheses about the relative influence of prey abundance, habitat structure and extent, and proximity to habitat edges on spatial variation in tiger densities across a gradient of anthropogenic disturbance. We documented extensive variation in tiger density within and across management units and protected areas. Spatial variation in prey abundance and proximity to grassland habitats, rather than human use (e.g. extent of human-dominated edge habitat and protection status), explained most of the spatial variation in tiger density in two of the five surveyed sites. The region’s largest tiger population occurred in a multi-use forest beyond protected area boundaries, where wild ungulates were abundant. Our results suggest that tigers can occur at high densities in areas with extensive human use, provided sufficiently high prey densities, and tracts of refuge habitats (eg. areas with dense vegetation with low human use). We argue that tiger conservation portfolio can be expanded across multi-use landscapes with a focus on areas that are adaptively managed as “zones of coexistence” and “refuge habitats”. Advancing this conservation strategy is contingent on greatly strengthening systems to effectively and equitably redress human–wildlife conflict and leveraging existing policies to strengthen local participation in conservation planning and forest stewardship. Our insights into the environmental drivers of spatial heterogeneity in tiger populations can inform both local management and guide to species recovery in working landscapes.

Human-wildlife conflicts (sudden increase in tiger attacks on humans) in adjacent areas of Corbett National Park Ramnagar Uttarakhand, India (from November 2023 to January 2024)

Human-wildlife conflicts become a common problem in Ramnagar tehsil of district Nainital in Uttarakhand state in India. The incidence of tiger attacks has suddenly increased in the villages adjoining Corbett Park, Ramnagar Forest Division and Tarai-West Forest Division during three months of winter (from November 2023 to January 2024). Tiger hunger, unavailability of adequate food (Cheetal/Sambar, etc.), man-eaters tigers, increasing population density of tigers, old age tigers with worn and broken claws, disturbance of their alertness and breeding (by noise of safari, bike and public vehicle), large herds of Cheetal in villages near the forest, foreign tiger in this area, need for tiger territory in buffer area (shrinking territory) etc. are main reasons for tiger attacks in these incidences. Both humans and tigers are affected by these conflicts. After these incidents, the Forest department cut small trees and bushes on both sides of the road from the buffer area (about 20-30 feet) and the road has become clear. With this, the tiger will not be able to hide in the bushes on the roadside and sit in ambush, and tiger attacks will be reduced.

Predicting carrying capacity of a large carnivore from prey densities: a new approach.

Large carnivores play a crucial role in maintaining the balance of the ecosystem. Successful conservation initiatives have often led to a huge increase in predators which has often led to negative interactions with humans. Without the knowledge of the carrying capacity of the top predator, such decisions become challenging. Here, we have derived a new equation to estimate the carrying capacity of tigers based on the individual prey species density. We used tiger densities and respective prey densities of different protected areas. Relative prey abundance was used instead of absolute prey density as this could be a better surrogate of the prey preference. We used a regression approach to derive the species-wise equation. We have also scaled these coefficients accordingly to control the variation in the standard error (heteroscedasticity) of the tiger density. Furthermore, we have extended this regression equation for different species to different weight classes for more generalized application of the method. The new equations performed considerably better compared to the earlier existing carrying capacity equations. Incorporating the species-wise approach in the equation also reflected the preference of the prey species for the tiger. This is the first carrying capacity equation where the individual prey densities are used to estimate the carnivore population density. The coefficient estimates of the model with the comparison with prey-predator power laws also reflect the differential effect of tigers on different prey species. The carrying capacity estimates will aid in a better understanding of the predator-prey interaction and will advance better management of the top predator.

Using a crime prevention framework to evaluate tiger counter-poaching in a Southeast Asian rainforest

Tigers are a conservation-reliant species, as multiple populations face the risk of local extinction due to poaching arising from the continued demand for their body parts. Preventing tiger poaching poses a challenge for the rangers responsible for their protection, particularly in Southeast Asia, where the protected areas are typically large, mountainous tropical forests guarded by small teams of rangers. Improving counter-wildlife crime tactics is hindered without robust evaluations, and inefficient approaches are perpetuated. We evaluate an eight-year project aiming to recover a tiger population in Peninsular Malaysia. Three distinct poaching problems by Vietnamese, Thai and Cambodian groups, differing by organisation, target species and tactics, were prioritised, and ranger counter-poaching tactics were tailored to reduce these. Applying a framework developed to evaluate crime prevention known by the acronym EMMIE, here we: (1) examine evidence our intervention was Effective in reducing the poaching threat; (2) resolve the Mechanisms by which our intervention caused a reduction in harm from poaching and how intervention effectiveness is Moderated by the three poaching types; (3) define the elements necessary for Implementation and the Economic costs involved. We found poaching incursion frequency fell 40% from baseline years to treatment years across all poaching types while poaching incursion depth declined, with disrupted incursions on average, 2.6 km (Thai) and 9.1 km (Cambodian) closer to the forest edge. However, wire snares increased from baseline to treatment years as Vietnamese poachers increased the number of snares per incursion eightfold. No poaching incursions were observed during the Covid-19 pandemic. Tiger density remained below recovery potential (0.48/100km2 in 2014 to 0.53/100 km2 in 2021) but stabilised as key females survived and were detected breeding. Leopard, sun bear, muntjac and wild boar densities remained stable. Disarming active snares and seizing an increased proportion of snares before being deployed directly reduced the potential risk of mortality to medium-large mammals once a poaching incursion began. Attributing the decline in poaching attempts to our intervention is supported for Cambodian poachers via three plausible mechanisms: increased cost of reoffending by repatriated poaching team leaders; reduction of detailed knowledge sharing and imitation by peers; general deterrence at community level from increased awareness of the elevated risk of arrest and low likelihood of enjoying rewards. We found ranger performance enhancements at three critical stages of counter-poaching were instrumental in increasing arrest certainty, this was made possible by institutionalising a learn-and-adapt cycle underpinned by a dedicated site analyst. This study highlights how investing in problem analysis and going beyond simple assumptions of deterrence can greatly enhance the effectiveness and efficiency of small wildlife protection teams.

Habitat suitability of a peatland landscape for tiger translocation on Kampar Peninsula, Sumatra, Indonesia

The risk of large carnivore mortality from anthropogenic sources is increased in areas where frequent human-carnivore encounters are high. Translocation is a potential tool for reducing these conflicts and re-establishing wild populations. Determining proper translocation sites for tigers is important for securing their future. In this research, we quantitatively evaluated the habitat suitability of a potential tiger translocation area on the Kampar Peninsula, a large peatland landscape in Sumatra. This landscape is essential for the conservation of the local tiger population, but its role as a tiger habitat has rarely been investigated. We conducted this research in a region with mosaicked land-use types covering an area of 7,045.89 km2. We applied species ecological niche factor analysis (ENFA) to model habitat suitability using species presence and ecogeographical variables as the bases. The model predicted that approximately 60% of the study area is tiger-suitable habitat with varying suitability levels. The tiger habitat characteristics in the study region are dissimilar to the global tiger habitat characteristics, and the high specialization value obtained indicates that tigers inhabit very narrow niches. Considering the low density of tigers in peatlands, we estimate that the carrying capacity of the whole Kampar landscape is approximately 13 tigers. Therefore, to conserve a viable tiger population, it is necessary to maintain connectivity between the Kampar peatlands and the Kerumutan landscape situated to the south of the Kampar Peninsula.

Setting recovery targets for a charismatic species in an iconic protected area complex: The case of tigers (Panthera tigris) in Chitwan–Parsa National Parks, Nepal

AbstractThe Global Tiger Recovery Program has identified enhancing prey populations as a crucial component in achieving its target of doubling wild tiger (Panthera tigris) numbers, as prey density is a key determinant of tiger density. We estimate prey abundance and ecological carrying capacity (ECC) of tigers in the 1579 km2 Chitwan–Parsa source site complex within a globally significant tiger conservation landscape in south‐central Nepal. Surveying 605.1 km of line transects in the Terai plains and Chure hills of Chitwan–Parsa, we estimated an overall density of 55.43 (36.98–83.45) ungulates/km2, and a biomass of 244,630 (151,520–334,270) kg/100 km2 of five abundant ungulates. Chitwan supports 71.58 (49.02–104.71) and Parsa 30.91 (18.70–51.19) ungulates/km2. The prey base can support 177 (119–263) adult tigers based on energetic requirement models. The tiger ECC was ~3.5× higher in Chitwan than in Parsa at a park level. Although opportunities for further recovery of tiger and prey through targeted habitat management exist, the current population of 170 tigers indicates that this population has likely reached its current ECC. We recommend that policymakers and park managers change focus from increasing tiger numbers to developing pre‐emptive conflict mitigation strategies to allow the site to retain the successes it has realized.

Spatio-temporal patterns of co-occurrence of tigers and leopards within a protected area in central India

Abstract. The global decline of large carnivore populations warrants scientific insights into intraguild relationships. Patterns of co-occurrence among sympatric predators are governed by their density, distribution, diet, activity overlaps, and behavioural strategies. Tigers are sympatric with leopards across their distribution range, overlap substantially in their diet, and are both nocturnal. The subdominant leopard is believed to coexist with tigers via several mechanisms like spatial segregation, temporal avoidance, and differential prey selection. Investigation of spatio-temporal patterns of co-occurrence of tigers and leopards can provide insights on mechanisms that permit coexistence. We used camera trap-based photo captures of tigers and leopards in prey-rich (58.15±10.61 ungulates per km2) Pench Tiger Reserve to determine their spatio-temporal patterns of co-occurrence. Spatially explicit density estimates of tigers were approximately 5 per 100 km2 and leopards were approximately 4.5 per 100 km2 and remained stable over the years. This implies that both these co-predators are likely to attain carrying capacity within the study area. Areas with high tiger density had lower leopard density. Quantile regression analysis between tiger and leopard density at 2×2 km grid showed that leopard density had a parabolic relationship with tiger density, initially increasing with tigers (β=0.393; p=0.001), stable at medium tiger density (β=0.13 and p=0.15), and declining at high tiger densities (β=-0.37 and p<0.001). Both tigers and leopards were crepuscular in nature with no temporal segregation (Δ=89 %). Time lag of consecutive leopard photograph after a tiger capture ranged between 0.002 to 36.29 d. Leopard use of trails was not related to use by tigers. Our results suggest that leopards adjust their usage of space at fine scales to avoid confrontations with tigers. We also observed high temporal overlap and no spatio-temporal segregation between tigers and leopards, despite the two predators being nocturnal and having similar prey choices. The availability of ample prey within the study area is likely to be the driving factor of the co-occurrence of tigers and leopards within this dry deciduous habitat of central India.

Carbonated tiger-high above-ground biomass carbon stock in protected areas and corridors and its observed negative relationship with tiger population density and occupancy in the Terai Arc Landscape, Nepal.

Healthy natural forests maintain and/or enhances carbon stock while also providing potential habitat and an array of services to wildlife including large carnivores such as the tiger. This study is the first of its kind in assessing relationships between above-ground biomass carbon stock, tiger density and occupancy probability and its status in protected areas, corridors, and forest connectivity blocks. The dataset used to assess the relationship were: (1) Converged posterior tiger density estimates from camera trap data derived from Bayesian- Spatially Explicit Capture-Recapture model from Chitwan National Park; (2) Site wise probability of tiger occupancy estimated across the Terai Arc Landscape and (3) Habitat wise above-ground biomass carbon stock estimated across the Terai Arc Landscape. Carbon stock maps were derived based on eight habitat classes and conservation units linking satellite (Landsat 7 ETM+) images and field collected sampling data. A significant negative relationship (r = -0.20, p<0.01) was observed between above-ground biomass carbon stock and tiger density in Chitwan National Park and with tiger occupancy (r = -0.24, p = 0.023) in the landscape. Within protected areas, we found highest mean above-ground biomass carbon stock in high density mixed forest (~223 tC/ha) and low in degraded scrubland (~73.2 tC/ha). Similarly, we found: (1) highest tiger density ~ 0.06 individuals per 0.33 km2 in the riverine forest and lowest estimates (~0.00) in degraded scrubland; and (2) predictive tiger density of 0.0135 individuals per 0.33 km2 is equivalent to mean total of 43.7 tC/ha in Chitwan National Park. Comparatively, we found similar above-ground biomass carbon stock among corridors, large forest connectivity blocks (~117 tC/ha), and within in tiger bearing protected areas (~119 tC/ha). Carbon conservation through forest restoration particularly in riverine habitats (forest and grassland) and low transitional state forests (degraded scrubland) provides immense opportunities to generate win-win solutions, sequester more carbon and maintain habitat integrity for tigers and other large predators.

Genetic evidence of differential dispersal pattern in the Asiatic wild dog: Comparing two populations with different pack sizes

IntroductionDispersal is a multi-causal, crucial life-history event in shaping the genetic and behavioral structure of mammals. We assessed the dispersal pattern of dholes aka Asiatic wild dog (Cuon alpinus), a social monogamous mammal at two tiger reserves of Maharashtra with different degrees of pack size and competition with tigers i.e. Tadoba-Andhari (TATR, smaller pack size, higher tiger density) and Nawegaon-Nagzira (NNTR, larger pack size, lower tiger density).MethodsWe used the microsatellite data of 174 individual genotypes (98 males and 67 females) to assess the dispersal pattern of dholes from two populations with varying pack size, tiger density, and landscape connectivity using gene flow as a proxy. We compared the population structure, pairwise F statistics, assignment index, and relatedness across a spatial scale.Results and discussionOverall, the results suggested a difference in sex-bias dispersal pattern for the two sub-populations, exhibiting significant results for female-biased dispersal in the TATR population with a smaller pack size and higher tiger density. Our study highlights the variability in sex-biased dispersal patterns in two different populations which could be the consequence of different variables such as pack size, tiger density, and geographical scale. The study warrants further quantitative investigation including several factors such as individual behavior, pack composition, pack size, tiger density, etc. In the present Anthropocene era, determining the sex bias in dispersal patterns for a short-range, pack-living carnivore will help in devising an effective conservation management plan for their long-term survival.

Density Estimation of Tiger (Panthera tigris) in the Buffer Zone of Corbett Tiger Reserve

Information about how many animals is in an area is essential for designing management strategies for endangered species such as tiger. Due to the tigers’ elusive behaviour, high mobility and occurrence at low densities, it is difficult to determine an unbiased estimate of tiger abundance. To overcome the problem, biologists proposed camera trapping as an effective method to determine the abundance of the tiger. We used camera trapping to determine the abundance and density of the tiger in the buffer zone of the Corbett Tiger Reserve. An effort of 240 trap nights results in the identification of 20 individual adult tigers. Tiger density was estimated at 13.69±3.3 tigers per 100 km 2 . Our estimation of tiger density highlighted the role of the buffer zone in landscape-level conservation of tigers and indicated that buffer zones can support the high density of tigers if appropriately managed. Anthropogenic activities exert enormous pressure on the buffer zone and it is imperative to have holistic management strategies for the long-term conservation of tigers in the human-dominated landscape of Corbett Tiger Reserve.

The tide of tiger poaching in India is rising! An investigation of the intertwined facts with a focus on conservation.

Poaching and illegal trafficking are major threats to biodiversity, especially when endangered felids are concerned. Tigers are iconic animals, and there is huge demand for their body parts both in the national and international illegal markets. India forms the largest tiger conservation unit in the world and poaching is at its peak even though there are stringent laws and strict enforcement. In the present study, we analytically estimated the tiger seizure cases in India from 2001–2021 using newspaper archives as the main source of data. The data was geo-referenced to understand the details of seizure, demand, and locality. We statistically correlated the seizure rate with the density of tigers, tiger reserves, and various other socio-economic factors. Our result shows that skin, claws, bones, and teeth have more demand, with nails and teeth being the most preferred in local markets. The bones, flesh, and other parts were mostly seized in the border states of the north and eastern states. The intensity of seizures is very high in the states of Maharashtra, Karnataka, Tamil Nadu, and Assam. From our analysis, we predict four trade routes for the export of the seized parts: the Nepal-Bhutan border, Assam border, the Brahmaputra, and the Mumbai port. This corresponds to the five tiger conservation blocks in India, and we observed the seizure rate is high near the Western Ghats region, which has not yet been noticed. Apart from the seizure, we are unconcerned with the seizure's origin or the local trading routes. The study demonstrates the importance of identifying the source population using DNA methods and carefully enforcing the rules in area of poaching. We assert that current approaches are incapable of resolving the issue and that a more precise and effective forensic procedure capable of resolving the issue at the minute local level is critical for precisely tracing trade channels.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10708-022-10633-4.

Panthera tigris altaica (Carnivora, Felidae) in the Lazovsky State Nature Reserve and in the adjacent non-protected area (Far East of Russia)

To assess the state of the Panthera tigris altaica (hereinafter – tiger) population, its annual monitoring is being carried out on 16 sites within its range, as this subspecies is still considered threatened. These sites include state nature reserves and adjacent territories, which differ in their protection status. In this paper, a number of tiger individuals in groups and reproduction have been compared on these sites to identify factors that determine these parameters. The tiger population in the Lazovsky State Nature Reserve (area of 1210 km2) was compared with the tiger population in an unprotected area (area of 988 km2), which, similarly to the Protected Area, is located on the coast of the Sea of Japan. A description and comparison of these two sites is given. The study has been carried out in 1997–2021 in the Lazovsky State Nature Reserve, and in 1997–2012 in the unprotected site «Lazovsky District». During the winter, information was collected about tiger tracks in the study area, and data on predator tracks were collected out on stationary routes during two field counts. In the Lazovsky State Nature Reserve, the density of routes in various years was 1.0–1.5 km per 10 km2, 1.2 km per 10 km2 in the site «Lazovsky District». Tiger individuals were identified by the width of paw prints. Tracks differed by more than 2 cm were considered belonging to different individuals. Indicators of the tiger population was about twice higher in the Lazovsky State Nature Reserve than in the unprotected site «Lazovsky District». In 1997–2012, in both Lazovsky State Nature Reserve and unprotected site «Lazovsky District», the population density of both adult and subadult tigers was respectively 8.6 ± 0.7 individuals per 1000 km2 and 5.3 ± 0.5 individuals per 1000 km2, while this parameter was respectively 3.1 ± 1.0 individuals per 1000 km2 and 1.7 ± 0.04 individuals per 1000 km2 for tiger cubs younger than a year. The tiger track density in the Lazovsky State Nature Reserve was 3.03 ± 0.51 tracks per 100 km, taking into account the time passed after the snowfalls covering all tracks; on the site «Lazovsky District», this indicator was 1.33 ± 0.27 tracks per 100 km. In 1997–2012, the population density of adults and subadults was significantly (F = 59.40, p &lt; 0.001) higher in the Lazovsky State Nature Reserve than on the site «Lazovsky District». The population density of tiger cubs (F = 6.30, p &lt; 0.018) and the track density (F = 4.86, p &lt; 0.036) were also significantly higher in the Protected Area than in the unprotected one. The survival rate of tiger cubs was also higher in the Lazovsky State Nature Reserve. Here, the proportion of tiger litters with one cub was 16% (n = 4), with two cubs 48% (n = 12), with three 32% (n = 8), and with four 4% (n = 1) of the total number. On the unprotected site «Lazovsky District», the proportion of litters with one cub was 53% (n = 8), with two 27% (n = 4), and with three 20% (n = 3) of the total number. A downward trend in the population density of tiger cubs was found on the site «Lazovsky District». In 2012–2021 in the Lazovsky State Nature Reserve, the average population density was 8.9 ± 1.8 individuals per 1000 km2 for adult and subadult tigers, and 4.3 ± 1.1 individuals per 1000 km2 for tiger cubs, while the average tiger track density was 2.39 ± 0.68 tracks per 100 km. During this period, the population density of tiger cubs decreased in the Protected Area, and there was also a tendency towards a decrease in the relative number of adults and subadults. The regular three-year cycle in the dynamics of the tiger track density in the Lazovsky State Nature Reserve indicates that environmental factors predominantly influence tiger groups here. No regular cycle was observed on the unprotected site «Lazovsky District». This finding and the lower number of tiger individuals in this area are associated with the negative impact of related anthropogenic factors, namely poaching, hunting, and logging. Recreational pressure also affects the tiger groups. In the last decade, the tiger group in the Lazovsky State Nature Reserve has been exposed to anthropogenic factors from the adjacent area. It is concluded that the further protection of the tiger and the increase in its number is possible if Protected Areas of various statuses are established, if extensive buffer zones are created around new and existing Protected Areas, if hunting is prohibited and logging is limited. The use of agricultural lands for other purposes around Protected Areas should be forbidden.

Coexistence of large carnivore species in relation to their major prey in Thailand

Spatial and temporal partitioning often facilitates species coexistence. We used camera traps to study habitat use and spatio-temporal interactions among three large carnivores—tiger, leopard, and dhole—in two national parks in Thailand where key prey species (sambar, gaur) were scarce from overhunting. The availability of remnant sambar was the strongest determinant of tiger occupancy. Leopard occupancy was positively related to the presence of wild pig. Dhole occupancy was negatively associated with sambar, opposite to tiger. Results of two-species occupancy modeling did not support our hypothesis that leopard would be excluded from tiger-occupied zones, but leopard detectability was seven times lower in the presence of tigers, indicative of fine-scale avoidance. Dhole avoidance of sambar might have been a tactic by which dhole avoided tigers. All three carnivores were mainly diurnal and thus had high temporal overlap (> 80%). Tiger density may have been too low (0.36/100 km2) to compel temporal avoidance by leopard and dhole where they overlapped. Our results suggest that low density populations of tigers and leopards can overlap in habitat use and temporal activity, despite the potential for intensified competition due to prey scarcity. Dholes were widespread despite scarcity of large ungulates, and seem more resilient to the loss of large-bodied prey than tigers. MWKL has an important role in conserving dholes, which are declining globally.

Tiger density, movements, and immigration outside of a tiger source site in Thailand

AbstractLandscape‐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.

The development status and evaluation of Hunchun wild Amur tiger reserve and Sino-Russian ecological corridor construction

Jilin Hunchun Wild Amur Tiger Park National Nature Reserve is China's first national-level tiger and leopard nature reserve with the highest number and density of wild Amur tigers and leopards in China. The reserve had become a part of ecological corridor for tigers to freely migrate between China and Russia. China provided a significant protection zone to address the threat of small population of Amur tiger. The solution published in China and effectiveness of the protection zone are discussed in this paper. Even more solutions are planned to be achieved through cooperation between China and Russia.

Dhole pack size variation: Assessing the effect of Prey availability and Apex predator.

In multipredator systems, group sizes of social carnivores are shaped by the asymmetric intraguild interactions. Subordinate social carnivores experience low recruitment rates as an outcome of predation pressure. In South and Southeast Asia, the Tiger (Panthera tigris), Dhole (Cuon alpinus), and Leopard (Panthera pardus) form a widely distributed sympatric guild of large carnivores, wherein tigers are the apex predators followed by dhole and leopard. In this study, we attempted to understand the variation in pack size of a social carnivore, the dhole, at two neighboring sites in the Central Indian landscape. We further evaluated local‐scale patterns of variation in pack size at a larger scale by doing a distribution‐wide assessment across the dhole ranging countries. At the local scale, we found an inverse relationship between the density of tiger and pack size of dhole while accounting for variability in resources and habitat heterogeneity. Larger dhole packs (16.8 ± 3.1) were observed at the site where the tiger density was low (0.46/100 km2), whereas a smaller pack size (6.4 ± 1.3) was observed in the site with high tiger density (5.36/100 km2). Our results for the distribution‐wide assessment were concordant with local‐scale results, showing a negative association of pack size with the tiger densities (effect size −0.77) and a positive association with the prey abundance (effect size 0.64). The study advances our understanding to answer the age‐old question of “what drives the pack size of social predators in a multipredator system?” This study also highlights the importance of understanding demographic responses of subordinate predator for varying competitor densities, often helpful in making informed decisions for conservation and management strategies such as population recovery and translocation of species.

Density estimation of tiger and leopard using spatially explicit capture-recapture framework.

The conservation of large carnivores often requires precise and accurate estimates of their populations. Being cryptic and occurring at low population densities, obtaining an unbiased population estimate is difficult in large carnivores. To overcome the uncertainties in the conventional capture–recapture (CR) methods used to estimate large carnivore densities, more robust methods such as spatially explicit capture-recapture (SECR) framework are now widely used. We modeled the CR data of tiger (Panthera tigris tigris) and leopard (Panthera pardus fusca) in the SECR framework with biotic and abiotic covariates likely believed to influence their densities. An effort of 2,211 trap nights resulted in the capture of 33 and 38 individual tigers and leopards. A total of 95 and 74 detections of tigers and leopards were achieved using 35 pairs of camera traps. Tiger and leopard density were estimated at 4.71 ± 1.20 (3.05–5.11) and 3.03 ± 0.78 (1.85–4.99) per 100 km2. Our results show that leopard density increased with high road density, high terrain ruggedness and habitats with high percentage of cropland and natural vegetation. The tiger density was positively influenced by the mosaic of cropland and natural vegetation. This study provides the first robust density estimates of tiger and leopard within the study area. Our results support the notion that large carnivores can attain moderate densities within human-dominated regions around protected areas relying on domestic livestock. Broader management strategies aimed at maintaining wild prey in the human-dominated areas around protected areas are necessary for large and endangered carnivores’ sustenance in the buffer zones around protected areas.

How can spatio-temporal overlap in mammals assist in maximizing biodiversity conservation? A case study of Periyar Tiger Reserve

While global mammalian diversity is collapsing due to increased poaching and habitat loss, evidence-based conservation in protected areas is often regarded as a panacea. Tiger reserves in India set an example, where annual camera trap monitoring is conducted for understanding the trends in the tiger population. However, less is known about other co-predators and their prey species that occur in the same area. The fundamental hindrance being the absence of individual pelage pattern within these species (i.e. unique pattern on the body), as well as the absence of species-specific monitoring. As a result, there is a demand in techniques that can avail maximum biodiversity information from the existing monitoring protocols. Here, we conducted camera trapping in Periyar Tiger Reserve to evaluate spatiotemporal overlaps within different carnivores, and between prey-predators. Camera trapping was conducted at high resolution (2 km2) for 30 days at 253 locations that yielded 6092 photographs of 18 mammals. Their temporal overlap was estimated using ‘overlap’ R package, while the spatial association was estimated using ‘co-occur’ package. Three large-ranging top predators (tiger, leopard and dhole) were found to have activity peaks segregated temporally. Relationship of these predators with their prey species highlighted the role of body sizes, where largest predator (tiger) had higher overlap with large-bodied prey (gaur and sambar), while small-bodied predator (leopard and dhole) overlapped small-bodied prey (barking deer and wild pig). Results highlight the importance of large-sized prey in conserving the tiger densities of this region. However, selectively conserving only large-bodied prey can have repercussions on other sympatric carnivores, who require different body-sized prey species. Our results have implications for all protected areas in the tropical developing countries, which are mostly smaller in area with species-centered conservation agenda. We highlight the importance of considering species-specific carrying capacity of all co-predators in the region, to optimally conserve the prey-base through habitat restoration, so as to maximize biodiversity conservation within a limited area.

Tigers at higher elevations outside their range: What does it mean for conservation?

Nepal’s population of endangered Bengal tigers (Panthera tigris) is on the rise. In recent years, the presence of tigers has been documented at higher elevations. The objective of this study is to explore the possible reasons for the tigers’ presence at the higher elevations. It is critical that these high-altitude habitats for tigers be further explored and protected. The study points out the importance of the Mahabharat range and a longitudinal conservation gradient approach in Nepal. Apart from this, it is imperative to assess the density of tigers and tiger prey in the area. Even though high-altitude ecology may be suitable for tiger growth, the formulation of a high-altitude tiger conservation action plan with effective coordination between stakeholder organizations and concerned departments is of great importance.