Search Results (16)

The gut microbiome plays a crucial role in the health and physiology of tigers (Panthera tigris), influencing digestion, immune function, and overall well-being. While numerous studies have characterized the gut microbiota of domestic carnivores and some wild felids, comparative analyses across different tiger subspecies under varying environmental contexts remain limited. In this exploratory study, we investigated the gut microbiome diversity and composition of 15 captive tigers, including both Siberian (P. tigris altaica) and Bengal (P. tigris tigris) subspecies, housed in two different regions in Korea. Using 16S rRNA gene sequencing of fecal samples, we analyzed microbial diversity across multiple taxonomic levels. Preliminary analyses revealed significant differences in microbial composition between geographic locations, whereas sex-based differences appeared minimal. Alpha and beta diversity metrics demonstrated substantial inter-individual variability, likely influenced by regional and environmental factors. Given the small sample size and the confounding between subspecies and housing location, the findings should be regarded as preliminary and not generalized beyond this specific cohort. Nevertheless, these insights highlight the potential utility of gut microbiome profiling for health monitoring and management in captive-tiger populations. Future research incorporating larger, more diverse cohorts will be essential to validate these trends and clarify the roles of diet, health status, and enrichment in shaping the gut microbiota. Full article

This study was carried out at 10 randomly selected fringe villages of Buxa Tiger Reserve (BTR) in the Terai region of West Bengal, India through personal interviews with 100 randomly selected respondents. The study documented 102 non-timber forest products (NTFPs) that were utilized throughout the year. In the local weekly market, 28 NTFPs were found to be traded by the collectors. The study shows that without proper price mechanisms and marketing channels; the residents cannot obtain fair prices for their products. The study found only nine NTFPs that were prominently traded with the involvement of middlemen and traders along with the royalty imposed by the State Forest Department. The MSPs computed for these nine NTFPs were 25–200% higher than the prices the collectors were selling to the traders. The nationalization of NTFPs through MSPs will help their effective marketing, ensuring an adequate income for the collectors, which will lead to their sustainable harvest and conservation through participatory forest management. Introducing MSPs for NTFPs with an efficient procurement network can advance the economic status of the inhabitants. We recommend increasing the inhabitants’ capacity to collect, store, process, and market NTFPs with active policy, institutional, and infrastructural support. Full article

The conservation of biodiversity and the balance between ecological and societal needs are critical but often contested global issues. Wildlife-vehicle collision (WVC) on vital infrastructure, especially linear infrastructure, remains a persistent challenge from policy to practice and poses a serious life-threatening implication to humans and other non-human lives. Addressing this issue effectively requires solutions that provide win-win outcomes from both ecological and societal perspectives. This study critically analyzes a decade of roadkill incidents along Nepal’s longest East-West national highway, which passes through a biologically diverse national park in the western Terai Arc Landscape Area (TAL). Findings are drawn from field-based primary data collection of the period 2012–2022, secondary literature review, key informant interviews, and spatial analysis. The study reveals significant variations in roadkill incidence across areas and years. Despite Bardia National Park being larger and having a higher wildlife density, Banke National Park recorded higher roadkill rates. This is attributed to insufficient mitigation measures and law enforcement, more straight highway segments, and the absence of buffer zones between the core park and adjacent forest areas—only a road separates them. Wild boars (Sus scrofa) and spotted deer (Axis axis), the primary prey of Bengal tigers (Panthera tigris tigris), were the most frequently road-killed species. This may contribute to human-tiger conflicts, as observed in the study areas. Seasonal trends showed that reptiles were at higher risk during the wet season and mammals during winter. Hotspots were often located near checkpoints and water bodies, highlighting the need for targeted mitigation efforts such as wildlife crossings and provisioning wildlife requirements such as water, grassland, and shelter away from the regular traffic roads. Roadkill frequency was also influenced by forest cover and time of day, with more incidents occurring at dawn and dusk when most of the herbivores become more active in search of food, shelter, water, and their herds. The findings underscore the importance of road characteristics, animal behavior, and landscape features in roadkill occurrences. Effective mitigation strategies include wildlife crossings, speed limits, warning signs, and public education campaigns. Further research is needed to understand the factors in driving variations between parks and to assess the effectiveness of mitigation measures. Full article

The conservation of Siberian tigers, the apex predators in the Asia–Pacific region, hinges on a thorough understanding of their physiological statuses and adaptive mechanisms. In order to fill a critical gap in our knowledge of this endangered species, we conducted comprehensive analyses of Siberian tiger whole blood and serum using modern hematology and biochemical analyzers. The blood samples were collected from subadult (2–3 years old) Siberian tigers (n = 15 for hematological analysis and n = 7 for biochemical analysis). In the present study, distinct hematological patterns including an elevated mean platelet volume (MPV) and a higher red cell distribution width coefficient of variation (RDW-CV) were observed, which were possibly triggered by pre-anesthesia resistance movements. Notably, the neutrophil percentage in Siberian tigers was found to be significantly higher than that in domestic cats and Bengal tigers, suggesting species-specific immune adaptations. In addition, serum biochemical analysis provided refined parameter ranges for subadult tigers. Unlike previous studies encompassing a broader age range, our data specifically characterize biochemical profiles in subadult tigers, offering vital baselines for health monitoring and conservation strategies. These results not only enhance our understanding of the biology of Siberian tigers but also provide scientific support for targeted conservation efforts, fostering population recovery and ecological balance in their natural habitats. Full article

In order to optimize diets for Bengal tiger cubs and improve their health condition and survival rates, we conducted microbiota and metabolomics analyses on fecal samples from Bengal tiger cubs fed goat and dog milk replacer formulae. The results showed that there were significant differences in fecal microorganisms and metabolites between the two groups. At the phylum level, the major components of the microbial composition in the feces of cubs were Firmicutes, Actinobacteriota, Proteobacteria, Bacteroidota and Fusobacteriota. In addition, the abundance of gut microbiota varied significantly between the two groups of tiger cubs. The fecal microbiota of the tiger cubs fed dog milk replacer powder exhibited an increase in probiotic bacteria (Anaerostipes and Clostridium_scindens) (p < 0.05), and the microbial community tended to be more balanced. Metabolomics data further elucidated that feeding different milk formulae significantly affected the fecal metabolites and metabolic pathways in the Bengal tiger cubs. In the dog milk replacer powder group, 76 metabolites were up-regulated (p < 0.05), and 278 metabolites were down-regulated (p < 0.05), particularly affecting the metabolism of vitamin D3, vitamin B5, isoleucine, valine, phenylalanine and oleic acid. At the same time, 19 metabolic pathways were affected (p < 0.05), including the amino acid metabolism, lipid metabolism and nucleotide metabolism pathways. In conclusion, this study confirms that milk formula composition affects the gut microbiota and metabolism of Bengal tiger cubs. These findings may provide new insights into how different milk powder formulae and dietary strategies influence the regulation of gut microbiota and overall health in Bengal tiger cubs. Full article

Penaeus monodon (tiger shrimp), Metapenaeus monoceros (brown shrimp), and Fenneropenaeus indicus (white shrimp) are the most economically important shrimp species in the waters of the Bay of Bengal, Bangladesh. This is the first analytical study to assess three major shrimp stocks using both length-based and catch-based methods, such as length-based Bayesian biomass estimation (LBB), length-based indicator (LBI), and a catch-based method entitled JABBA (Just Another Bayesian Biomass Assessment), to explore and process the data; estimate the growth parameters, with length at first capture; present relative biomasses; and approximate the reference points. The parameters of the von Bertalanffy Growth Function (VBGF) analysis for the tiger, brown, and white shrimps were L_∞ = 113.0 mm, 85.4 mm, and 76.4 mm, respectively, for carapace length. Our results showed that the relative biomass level (B/B_MSY) of the tiger shrimp was 0.43, suggesting an overfished status, and brown and white shrimps were 0.84 and 0.96, indicating that they were fully exploited but not overfished. This study, therefore, advised an optimum carapace length limit to catch from 57.0–70.0 mm for tiger shrimp, 44.0–53.0 mm for brown shrimp, and 40.0–48.0 mm for white shrimp. The estimated maximum sustainable yield (MSY) reference points were as follows: optimal biomass B_MSY = 3116 mt, 15,885 mt, and 2649 mt for tiger, brown, and white shrimp, respectively, and optimal harvest rate uMSY = 12%, 33%, and 8% for tiger, brown, and white shrimp, respectively. The average annual catch values for the last ten years were 265 mt, 2396 mt, and 115 mt below the estimated MSY values of 389 mt, 4899 mt, and 209 mt for tiger, brown, and white shrimp, respectively. But, brown shrimp had the estimated highest carrying capacity (31,770 mt) and intrinsic growth rate (0.66) than the tiger and white shrimp, which was replicated distinctly in the graphical representation of the Kobe plot and the surplus production plot. Hence, the brown shrimp stock is estimated to be in a better state than the tiger and white shrimp stocks. Full article

The Bengal tiger (Panthera tigris tigris) is critically endangered, so assisted reproductive technologies, including artificial insemination, are important conservation tools. For wild and domestic felids, electroejaculation (EE) is the most common semen collection method, with protocols optimized to obtain sufficient amounts of viable sperm for artificial insemination. However, less attention has been paid to ensuring animal wellbeing during the process. This study examined the effects of three EE protocols (Low, 2–5 volts; Medium, 3–6 volts; High, 4–7 volts) on semen quality, testicular size, serum testosterone, creatine kinase (CK), and malondialdehyde (MDA) concentrations, and serum cortisol as a proxy for stress. Blood samples were collected before, during, and after each EE series. Seminal plasma pH, and sperm motility, viability, and morphology were evaluated after each procedure. Seminal plasma and sperm pellet MDA concentrations were also determined. Primary sperm abnormalities and seminal plasma MDA were higher in the Low compared to Medium and High voltage groups (p < 0.05). Serum CK in the High voltage group increased during the EE series (p < 0.05), suggesting the potential for muscle damage. However, no significant changes were observed for serum cortisol, testosterone, or MDA concentrations. Results suggest the Medium voltage protocol produced good quality samples at lower voltages than the High protocol with no negative effect on muscle function, which might be better for animal welfare. Full article

From wild dogs (Lycaon pictus) in the Serengeti to tigers (Panthera tigris altaica) in the Russian Far East, canine distemper virus (CDV) has been repeatedly identified as a threat to wild carnivores. Between 2020 and 2022, six Indian leopards (P. pardus fusca) presented to Nepali authorities with fatal neurological disease, consistent with CDV. Here, we report the findings of a serosurvey of wild felids from Nepal. A total of 48 serum samples were tested, comprising 28 Bengal tigers (P. t. tigris) and 20 Indian leopards. Neutralizing antibodies were identified in three tigers and six leopards, equating to seroprevalences of 11% (CI: 2.8–29.3%, n = 28) and 30% (CI: 12.8–54.3%, n = 20), respectively. More than one-third of seropositive animals were symptomatic, and three died within a week of being sampled. The predation of domestic dogs (Canis lupus familiaris) has been posited as a potential route of infection. A comparison of existing diet studies revealed that while leopards in Nepal frequently predate on dogs, tigers do not, potentially supporting this hypothesis. However, further work, including molecular analyses, would be needed to confirm this. Full article

Although research on wildlife species across taxa has shown that males and females may differentially select habitat, sex-specific habitat suitability models for endangered species are uncommon. We developed sex-specific models for Bengal tigers (Panthera tigris) based on camera trapping data collected from 20 January to 22 March 2010 within Chitwan National Park, Nepal, and its buffer zone. We compared these to a sex-indiscriminate habitat suitability model to assess the benefits of a sex-specific approach to habitat suitability modeling. Our sex-specific models produced more informative and detailed habitat suitability maps and highlighted vital differences in the spatial distribution of suitable habitats for males and females, specific associations with different vegetation types, and habitat use near human settlements. Improving and refining habitat models for this and other critically endangered species provides the necessary information to meet established conservation goals and population recovery targets. Full article

The tiger (Panthera tigris) is an endangered species. The health of individuals is important and any data on hematological and biochemical blood values can provide valuable information; when combined with physical assessment. This data assists in both the diagnosis of disease and some conservation strategies. The behavior of wild tigers makes it is extremely difficult to obtain biological samples from free-living subjects, therefore, data collected from captive tigers is highly valuable. The aim of this study was to provide additional information for the values of hematological and serum biochemical parameters in healthy captive tigers. Blood samples were collected from 22 clinically healthy tigers (Panthera tigris). The following parameters were analyzed: glucose, urea, creatinine, alanine aminotransferase (ALT), alkaline phosphatase (ALP), total protein (TP) and red blood cells (RBCs), hemoglobin (Hb), hematocrit (Hct) and red cell indices; such as mean cell volume (MCV), mean cell Hb (MCH), mean cell Hb concentration (MCHC), platelet (PLT) and white blood cells (WBCs). The mean hematological values in our tiger population were not significantly different when compared with the same parameters in the previously studied tiger population. The mean values of RBCs and PLT were statistically significantly higher and the mean values of Hb, PCV, MCV, MCH, MCHC, and WBC were lower than the mean values obtained in previous studies on the Amur tiger. Further investigation of captive and free-living tigers is needed to identify the normal ranges for parameters in this endangered species. Full article

The United Nations Sustainable Development Goals (SDGs) and their corresponding targets are significantly interconnected, with many interactions, synergies, and trade-offs between individual goals across multiple temporal and spatial scales. This paper proposes a framework for the Integrated Assessment Modelling (IAM) of a complex deltaic socio-ecological system in order to analyze such SDG interactions. We focused on the Sundarban Biosphere Reserve (SBR), India, within the Ganges-Brahmaputra-Meghna Delta. It is densely populated with 4.4 million people (2011), high levels of poverty, and a strong dependence on rural livelihoods. It is adjacent to the growing megacity of Kolkata. The area also includes the Indian portion of the world’s largest mangrove forest––the Sundarbans––hosting the iconic Bengal Tiger. Like all deltaic systems, this area is subject to multiple drivers of environmental change operating across scales. The IAM framework is designed to investigate socio-environmental change under a range of explorative and/or normative scenarios and explore associated policy impacts, considering a broad range of subthematic SDG indicators. The following elements were explicitly considered: (1) agriculture; (2) aquaculture; (3) mangroves; (4) fisheries; and (5) multidimensional poverty. Key questions that can be addressed include the implications of changing monsoon patterns, trade-offs between agriculture and aquaculture, or the future of the Sundarbans’ mangroves under sea-level rise and different management strategies. The novel, high-resolution analysis of SDG interactions allowed by the IAM will provide stakeholders and policy makers the opportunity to prioritize and explore the SDG targets that are most relevant to the SBR and provide a foundation for further integrated analysis. Full article

Given the endangered status of tigers (Panthera tigris), the health of each individual is important and any data on blood chemistry values can provide valuable information alongside the assessment of physical condition. The nature of tigers in the wild makes it is extremely difficult to obtain biological samples from free-living subjects, therefore the values obtained from captive tigers provide very useful data. Serum protein electrophoresis is a useful tool in the diagnosis and monitoring of a number of diseases. In this study, we evaluated agarose gel serum protein electrophoresis on samples from 11 healthy captive tigers. Serum electrophoresis on all 11 tiger samples successfully separated proteins into albumin, α₁, α₂, β₁, β₂ and γ globulin fractions as in other mammals. Electrophoretic patterns were comparable in all tigers. Mean± standard deviation or median and range values obtained for each protein fraction in healthy tigers were, respectively: 3.6 ± 0.2, 0.21 (0.2–0.23), 1.2 ± 0.2, 10.7 ± 0.2, 0.4 (0.3–0.6), 1.2 (1–1.8) gr/dL. The results of this preliminary study provide the first data on serum electrophoretic patterns in tigers and may be a useful diagnostic tool in the health assessment of this endangered species. Full article

The objective of our research was to describe the normal appearance of the bony and soft tissue structures of the elbow joint in a cadaver of a male mature Bengal tiger (Panthera tigris tigris) scanned via MRI. Using a 0.2 Tesla magnet, Spin-echo (SE) T1-weighting, and Gradient-echo short tau inversion recovery (GE-STIR), T2-weighting pulse sequences were selected to generate sagittal, transverse, and dorsal planes. In addition, gross dissections of the forelimb and its elbow joint were made. On anatomic dissections, all bony, articular, and muscular structures could be identified. The MRI images allowed us to observe the bony and many soft tissues of the tiger elbow joint. The SE T1-weighted MR images provided good anatomic detail of this joint, whereas the GE-STIR T2-weighted MR pulse sequence was best for synovial cavities. Detailed information is provided that may be used as initial anatomic reference for interpretation of MR images of the Bengal tiger (Panthera tigris tigris) elbow joint and in the diagnosis of disorders of this region. Full article

The Sundarbans is a deltaic mangrove forest, formed about 7000 years ago by the deposition of sediments from the foothills of the Himalayas through the Ganges river system, and is situated southwest of Bangladesh and south of West Bengal, India. However, for the last 40 years, the discharge of sediment-laden freshwater into the Bay of Bengal through the Bangladesh part of the Sundarbans Mangrove Forests (BSMF) has been reduced due to a withdrawal of water during the dry period from the Farakka Barrage in India. The result is two extremes of freshwater discharge at Gorai, the feeding River of the BSMF: a mean minimum monthly discharge varies from 0.00 to 170 m³·s⁻¹ during the dry period with a mean maximum of about 4000 to 8880 m³·s⁻¹ during the wet period. In the BSMF, about 180 km downstream, an additional low discharge results in the creation of a polyhaline environment (a minimum of 194.4 m³·s⁻¹ freshwater discharge is needed to maintain an oligohaline condition) during the dry period. The Ganges water carries 262 million ton sediments/year and only 7% is diverted in to southern distributaries. The low discharge retards sediment deposition in the forestlands’ base as well as the formation of forestlands. The increase in water flow during monsoon on some occasions results in erosion of the fragile forestlands. Landsat Satellite data from the 1970s to 2000s revealed a non-significant decrease in the forestlands of total Sundarbans by 1.1% which for the 6017 km² BSMF is equivalent to 66 km². In another report from around the same time, the estimated total forestland loss was approximately 127 km². The Sundarbans has had great influence on local freshwater environments, facilitating profuse growth of Heritiera fomes (sundri), the tallest (at over 15 m) and most commercially important plant, but now has more polyhaline areas threatening the sundri, affecting growth and distribution of other mangroves and biota. Landsat images and GIS data from 1989 to 2010 at the extreme northern part of Khulna and Chandpai Ranges revealed the formation of a large number of small rivers and creeks some time before 2000 that reduce the 443 km² forestland by 3.61%, approximately 16 km², and decreasing H. fomes by 28.75% and total tree cover by over 3.0%. The number of the relatively low-priced plants Bruguiera sexangula, Excoecaria agallocha and Sonneratia apetala, has, on the other hand, increased. Similar degradation could be occurring in other ranges, thereby putting the survivability of the Bangladesh Sundarbans at risk. The growing stock of 296 plants per ha in 1959 had been reduced to 144 by 1996. Trend analysis using “Table Curve 2D Programme,” reveals a decreased number of 109 plants by the year 2020. The degradation of the Bangladesh Sundarbans has been attributed to reduced sediment-laden freshwater discharge through the BSMF river system since commissioning the Farakka Barrage on 21 April 1975 in India. To reduce salinity and forestland erosion, the maintenance of sediment-laden freshwater discharge through its river system has been suggested to re-create its pre-1975 environment for the growth of H. fomes, a true mangrove and the highest carbon-storing plant of the Sundarbans. This may possibly be achieved by proper sharing of the Ganges water from the Farakka Barrage, forming a consortium of India, Nepal, Bhutan and China, and converting parts or whole of the Ganges River into water reservoir(s). The idea is to implement the Ganges Barrage project about 33 km downstream, dredging sediments of the entire Gorai River and distributaries in the Ganges floodplain, thus allowing uniform sediment-laden freshwater flow to maintain an oligohaline environment for the healthy growth of mangroves. The system will also create healthy hinterlands of the Ganges floodplain with increased crop production and revenue. The expenditure may be met through carbon trading, as Bangladesh is a signatory of the Copenhagen Accord, UN Framework Convention on Climate Change. The total carbon reserve in the BSMF in 2010 was measured at about 56 million metric tons, valued at a minimum of US$ 280 million per year. The forest is rich in biodiversity, where over 65 species of mangroves and about 1136 wildlife species occur. The BSMF acts as a natural wall, saving property as well as millions of lives from natural disasters, the value of which is between 273 and 714 million US$. A 15 to 20 km band impact zone exists to the north and east of the BSMF, with a human settlement of about 3.5 million that is partly dependent on the forests. Three wildlife sanctuaries are to the south of the BSMF, the home of the great royal Bengal tigers, covering a total area of about 1397 km². Construction of a coal-fired power plant at Rampal will be the largest threat to the Sundarbans. It is a reserve forest, declared as a Ramsar site of international importance and a UNESCO natural world heritage site. Full article

Covering approximately 10,000 km² the Sundarbans in the Northern Bay of Bengal is the largest contiguous mangrove forest on earth. Mangroves forests are highly productive and diverse ecosystems, providing a wide range of direct ecosystem services for resident populations. In addition, mangroves function as a buffer against frequently occurring cyclones; helping to protect local settlements including the two most populous cities of the world, Kolkata and Dhaka, against their worst effects. While large tracts of the Indian Sundarbans were cleared, drained and reclaimed for cultivation during the British colonial era, the remaining parts have been under various protection regimes since the 1970s, primarily to protect the remaining population of Bengal tigers (Panthera tigris ssp. tigris). In view of the importance of such forests, now severely threatened worldwide, we trace the areal change that the Indian Sundarbans have undergone over the last two-and-a-half centuries. We apply a multi-temporal and multi-scale approach based on historical maps and remote sensing data to detect changes in mangrove cover. While the mangroves’ areal extent has not changed much in the recent past, forest health and structure have. These changes result from direct human interference, upstream development, extreme weather events and the slow onset of climate change effects. Moreover, we consider the role of different management strategies affecting mangrove conservation and their intersection with local livelihoods. Full article