Mucormycosis is an angioinvasive fungal infection caused by ubiquitous saprophytic fungi of the order Mucorales. In humans, the infection is generally caused by inhalation of spores or traumatic inoculation in cutaneous wounds, typically affecting immunocompromised patients. In animals, Mucorales infection is common in cattle, but is rare in the other species, including felids. No cases of mucormycosis have been reported to date in non-domestic felids, to our knowledge. We describe a case of mucormycosis in a 5-y-old female captive tiger (Panthera tigris). The affected tiger was part of a group of 9 subjects, 7 of which had serohemorrhagic nasal discharge, anorexia, and depression, followed by hemorrhagic diarrhea. Five of the tigers died and organs from one animal were sent for histologic examination, which revealed severe necrohemorrhagic enteritis, with periodic acid-Schiff- and Grocott methenamine silver-positive fungal hyphae. Mucor colonies were cultured from sawdust, which served as litter for the animals, indicating a possible source of infection through inhalation of spores and/or ingestion of contaminated sawdust. Mucormycosis is a possible differential for necrohemorrhagic enteritis in captive felids; careful storage and periodic assessment of the materials used as litter for these animals is recommended.

SARS-CoV-2 rapidly adapts to new hosts following cross-species transmission; this is highly relevant as unique within-host variants have emerged following infection of susceptible wild and domestic animal species. Furthermore, SARS-CoV-2 transmission from animals (e.g., white-tailed deer, mink, domestic cats, and others) back to humans has been observed, documenting the potential of animal-derived variants to infect humans. Here, we investigate SARS-CoV-2 evolution and host-specific adaptation during an outbreak in Amur tigers (Panthera tigris altaica), African lions (Panthera leo), and spotted hyenas (Crocuta crocuta) at Denver Zoo in 2021. SARS-CoV-2 genomes from longitudinal samples from 16 individuals are evaluated for within-host variation and genomic signatures of selection, and we determine that the outbreak was likely initiated by a single spillover of a rare Delta sublineage. Within-host virus populations rapidly expand and diversify, and we detect signatures of purifying and positive selection, including strong positive selection in hyenas and in the nucleocapsid (N) gene in all animals. Four candidate species-specific adaptive mutations are identified: N A254V in lions and hyenas, and ORF1a E1724D, spike T274I, and N P326L in hyenas. These results reveal accelerated SARS-CoV-2 adaptation following host shifts in three non-domestic species in daily contact with humans.

Countries use lethal control as a tool to respond to human-large carnivore conflicts to varying degrees. The aim of this study was to explore the complexities surrounding the often-controversial decision to lethally manage carnivores. We examined the cases of the tiger (Panthera tigris) in India and the wolf (Canis lupus) in Germany. This study used an Institutional Analysis and Development framework to analyze contrasting sociopolitical processes. Through a review of legislative documents (n = 44) and interviews with experts (n = 47), the study examined the intricacies and challenges of the decision-making process and its implementation. While both countries were restrictive in their use of lethal control, decisions were primarily shaped by culturally embedded tolerance thresholds, accountability structures of decision-makers and influential societal factors. The findings demonstrate that effective carnivore management requires careful institutional design balancing scientific evidence with democratic participation.

ABSTRACTTiger (Panthera tigris) and leopard (Panthera pardus) are two congener species and wherever they live together are found to compete for space and habitat. The study on habitat suitability and overlap between tigers and leopards in the Banke‐Bardia Complex, Nepal, aims to assess the ecological preferences and spatial distribution patterns of these big cat species within the given landscape. For the study the Banke‐Bardia Complex was considered as it is one of the priority tiger conservation units. We have gathered the GPS location of tigers and leopards from the camera trap survey. Maximum Entropy (Maxent) is software used to model the suitable habitat of species by using geo‐referenced occurrence data and environmental variables. We used area under the receiver‐operator curve (AUC) as the threshold‐independent method. We found a fair AUC for the model of leopard (0.674+/−0.043) and tiger (0.690+/− 0.012) habitat suitability model. We found 854.15 km2 and 867.21 km2 of suitable habitat for common leopard and tiger respectively throughout the study area. We identified 388.16 km2 of overlapping habitat between the species, which constituted 45.60% of the habitat of leopard and 44.75% of the habitat of tiger. Most of the overlapping habitat was located in the southern part of Banke National Park and western parts of Bardia National Park. The findings from this study highlight the need for inclusive conservation strategies extending beyond core protected areas. Engaging local communities in conservation efforts and promoting sustainable land‐use practices can mitigate human‐wildlife conflicts and support broader ecological integrity.

ABSTRACTThe rebound of tiger populations in Nepal over the last decade has renewed hope for species conservation but also heightened the risk of conflict where humans and tigers coexist. Most of these tigers inhabit Chitwan–Parsa Complex (CPC), which includes core areas prohibiting humans and buffer zones allowing limited activities. To understand distribution within CPC and nearby forests, we constructed a Bayesian occupancy model using data from a sign survey conducted between December 2021 and February 2022. We estimated occupancy for 2021–22 dry‐season within CPC on a 10 km × 10 km gird and as well as the use by tigers and prey on a 2 km × 2 km subgrid. The average estimated occupancy ψ within 10 km × 10 km grids and detection p within 2 km × 2 km subgrids were 0.90 (95% CI 0.77–0.99) and 0.34 (95% CI 0.32–0.36), respectively. The presence of tigers was more strongly related to prey occupancy at the home‐range scale whereas factors such as vegetation, human population density (HPD), and elevation affected used portion of home range. HPD significantly reduced habitat use by tigers and prey. We compare our modeled tiger‐use distribution to an independent dataset containing conflict causing tiger rescue and relocation records. Tigers use only increased odds of rescues occurring in a subgrid by 10%, but subgrids with above average HPD had 2.2 times higher odds of rescues than those with low HPD, and the grids with above average prey use had 3.8 times higher odds of rescues than those with low prey. The pattern of increased rescues in high‐prey‐use areas was driven by subgrids with above average HPD, where the odds of rescues were 10.98 times higher than those with low prey use. The varying odds of conflict by HPD and prey use suggest future approaches to tiger conservation and conflict resolution.

Abstract Accurately describing large carnivore diets is crucial for understanding trophic interactions and developing targeted conservation strategies. Most studies have relied on traditional dietary analysis based on mechanical sorting and identification of undigested prey remains, a method known to be error‐prone and ecologically biased. Here, we compare the diet of tigers ( Panthera tigris ) using non‐invasively collected scats from Ranthambore Tiger Reserve in India, analyzed through mechanical sorting and DNA metabarcoding. We found that DNA metabarcoding outperformed mechanical sorting by detecting more overall prey and rare prey species, revealing greater prey diversity. The study indicated that tigers mainly subsist on wild prey such as sambar ( Rusa unicolor ) and chital ( Axis axis). However, domestic cattle contributed the largest proportion of prey biomass to their diet. Our findings demonstrate that DNA metabarcoding is an efficient, effective, and powerful approach that overcomes many of the biases associated with mechanical sorting, providing an accessible and particularly useful tool for carnivore dietary studies based on non‐invasive samples. The increased frequency of livestock depredation compared to previous studies emphasizes the urgency of taking active mitigation measures to safeguard this population.

This article presents an analysis of the effect of olfactory environmental enrichment on the behavior of Eurasian lynx, Lynx lynx (Linnaeus, 1758), in the Moscow Zoo during the summer and autumn of 2022. The research involved four adult lynxes (one male and three females). Environmental enrichment consisted of introducing the excrement of potential competitor species (Panthera tigris, Canis lupus, Gulo gulo) and prey species ( Capra cylindricornis, Lepus timidus, Cervus nippon ) of lynxes. Behavioral observations were conducted using Time Slice video recording. The influence of factors such as individual animal characteristics (sex, age), air temperature, observation time, and the introduction of olfactory environmental enrichment on the behavior of the lynxes was assessed. Results indicated that olfactory environmental enrichment significantly affected the frequency of both inactive and active behavioral patterns in the lynxes. An increase in the active behavior was observed following the introduction of all odors, except for the excrements of G. gulo and L. timidus . A decrease in the inactive behavior was observed in all cases, except for enrichment of the environment with excrements of L. timidus . Enrichment with C. cylindricornis manure resulted in the maximum increase in the locomotor activity in the lynxes.

ABSTRACT Increasing livestock depredation by recovering large carnivore populations undermines local support for long‐term conservation. Past studies on livestock depredation have primarily focused on biophysical predictors, often overlooking the role of household‐level husbandry and protection practices in shaping depredation risk. We used multivariate logistic regression models on a database of 1180 households (including 597 livestock depredation events) from the tropical lowlands of Nepal to identify predictors of livestock depredation by tigers ( Panthera tigris tigris ) and leopards ( Panthera pardus ). In line with previous research, models reported significant biophysical and livestock husbandry predictors of depredation risk, which are intrinsic geospatial and livelihood variables and unlikely to respond to interventions. In addition, we found novel evidence that the low‐cost protection strategies of fixed night lighting and domestic dog ownership significantly lowered the odds of small livestock depredation. With careful implementation, these two mitigation measures have the potential to reduce livestock depredation risk and contribute to human–wildlife coexistence.

ABSTRACTThe Bengal tiger (Panthera tigris tigris), a flagship and umbrella species of the South Asian forest ecosystem, has declined dramatically in population and geographic distribution due to human‐caused habitat fragmentation and poaching over the past century. Global tiger populations may persist in the next century only if the size and quality of the current habitat remain unchanged. Our first‐of‐its‐kind study in Nepal assesses whether these habitat requirements are in place through an analysis of habitat suitability to predict the future habitat of tigers in varying climatic scenarios across the country. We collected tiger‐presence location (GPS points) from tiger surveys conducted by the Department of National Parks and Wildlife Conservation, Nepal, in 2018 and 2022 across the country. We used MaxEnt software in varying Shared Socio‐economic Pathways (SSP 245 and 585) employing eight bioclimatic and two topographic variables to predict the future habitats of the tiger in 2050, 2070, and 2090. In the SSP 245 scenario, tiger habitat could increase for all three time periods, but in the SSP 585 scenario, the habitat will increase only in 2050. Interestingly, in both scenarios, tiger habitat will increase by more than 80% in 2050. The expanded habitat in all scenarios is outside of protected areas and northeast of the current habitat. This indicates that extreme climate change scenarios with more industrialization, urbanization, and land use change have a greater impact on tiger habitat. Furthermore, tiger habitat qualitatively shifts from protected areas to outside protected areas in the human‐dominated landscape. This creates more challenges for conservationists and managers as human‐tiger interaction may surge. Proactive management solutions to protect Nepal's tigers for the next century could include expanding or establishing new protected areas, establishing connectivity and corridors between the tiger habitats, in addition to anticipatory efforts to address human‐wildlife conflicts that will emerge in this changing landscape.

The interactions between animals and plants are the most critical processes in terrestrial ecosystems. Northeast China Tiger and Leopard National Park is one of China's first five national parks, where the recovery of the amur tiger (Panthera tigris altaica) and its prey populations is vital for biodiversity conservation. Wapiti (Cervus elaphus) is the class II national protected animal in China and one of the main prey of amur tiger. Taxus cuspidata is a Tertiary relict tree and the class I national protected plant and wapiti browsing its saplings is likely to increase its endangered status. Given that both species serve as key conservation priorities in the national park, there is an urgent need to address the ecological balance between them. From 2020 to 2024, we conducted camera traps, field investigation, and high performance liquid chromatography to study the interaction between them. We found that wapiti mainly browsed the saplings in 20-100cm. When the height reaches 250cm, it can avoid being browsed. After being browsed, saplings tend to abandon the growth of the main branches and focus on the recovery of lateral branches and ground diameters. The concentration of tannins doubles, while the concentration of terpenoids nearly triples and that of flavonoids almost doubles after browsed by wapiti. Wapiti did not browse the same saplings twice. In summary, although wapiti browsing inhibits the growth of saplings, the chemical defense also ensures that it is not browsed twice. The results not only provide a scientific basis for solving the cooperative conservation of wapiti and T. cuspidata but also promote the study of interaction and co-evolution between large herbivores and rare plants.

Prey depletion, direct poaching, and habitat fragmentation are driving global declines of carnivore species, but the specific consequences of these impacts on population demography have not been widely studied, obscuring an understanding of why some populations recover while others flounder. This 11-year study sought to uncover what constrains recovery of a low-density tiger population in Thailand, by investigating population dynamics with respect to three key mechanisms potentially affecting vital rates: tiger poaching, prey depletion, and immigration. Our site resembled most Southeast Asian tiger populations in that tiger and prey abundance were both low, but it was unusual in sharing landscape connectivity with the largest tiger population remaining in Southeast Asia. We identified tigers with camera traps and applied a Pradel robust design model to estimate survival, recruitment, immigration, and population growth rate. We obtained information on cub production through observations of dependent young with their mother. The small population (7-11 adults) was stable over time but did not increase ( = 1.006). This inertia corresponded with the status of key prey species, which occurred at low density and had flat population trends. Female survival rate was high (0.823), but reproduction rate (0.514) and cub survival (0.313) were 2-3 times lower than other tiger populations in Asia where prey availability is higher. This pattern of flat population trend, high adult survival, and low reproduction is indicative of the effects of prey scarcity, rather than direct poaching, as the essential constraint on recovery. Most recruitment of new tigers came from immigration, with 67% of the resident females being born outside, rather than locally. High female survival plus immigration were critical to sustaining this population, and represent an essential foundation for future recovery, but this potential is impeded by prey scarcity which suppresses reproductive success. Managers can unblock the path to recovery by increasing abundance and distribution of preferred prey. This would allow resident females to reproduce more consistently and boost survival rates of their cubs, while creating new high-quality habitats for additional females to settle in, whether they are locally born or arrive through immigration.

Management of dental disease in non-domestic felids under managed care is integral to their overall health and welfare. Accurate evaluation of dental disease by zoo clinicians improves patient care and can influence the decision to utilize dental specialists to assist with complex procedures. Additionally, dental disease frequently occurs subgingivally and cannot be detected without the aid of dental radiography and/or advanced imaging, such as CT. This study aimed to describe the frequency and types of dental pathology observed in a cohort of 15 tigers (Panthera tigris) from a sanctuary, determine the interexaminer agreement between a zoological medicine house officer and a board-certified veterinary dentist and identify subgingival lesions via CT imaging and correlate those findings to oral examinations. Abrasions, complicated crown fractures (CCFx), dental calculus, and periodontal pocketing were all observed in more than half of the individuals on dental examination and exhibited moderate or better interexaminer agreement based on statistical analysis. CT scans revealed alveolar bone loss (ABL) and periapical lysis (PL) most commonly in these same cats. PL was significantly positively correlated with CCFx (r = 0.45, P < 0.0001). These findings confirmed that dental trauma is the most common etiology for dental pathology in this population of tigers and that for most types of dental pathology observed, the zoological medicine house officer and veterinary dentist exhibited moderate agreement or better. Additionally, CT was useful for identifying subgingival lesions such as ABL and PL and may be an important diagnostic tool in cases of CCFx in tigers.

This case series describes the presentation, diagnostic, and pathologic findings for mesothelioma in ten Panthera felids at two sanctuaries. Over ten years, seven African lions (Panthera leo) and three tigers (Panthera tigris) were diagnosed with mesothelioma, with a median age of 18 years. The most common clinical signs were nonspecific (lethargy, hyporexia, weight loss) and respiratory (coughing, wheezing, dyspnea), linked to cavitary effusions. Hematology and biochemistry values did not show consistent abnormalities although elevated creatinine (4/10), neutrophilia (4/10), monocytosis (3/10), and hyperglobulinemia (4/10) were most common. Radiographs, echocardiograms, and fluid cytology identified effusion, but did not diagnose mesothelioma specifically. All pericardial fluid samples (collected from 3/10 cases) were hemorrhagic, one of which had mesothelial cells but were not definitively neoplastic and one had neoplastic cells but were not definitively mesothelial. Treatments were only palliative; therapeutic pericardiocentesis provided short-term relief for three animals. Median survival time from the onset of clinical signs was 50 (range 0-176) days. If not euthanized on presentation, cases were managed with a combination of antibiotics, antifungals, immunosuppressives, diuretics, cardiac medications, and supportive care. Cavitary effusions were identified in 8/10 of cases at necropsy, including pericardial (7/10), pleural (5/10), and peritoneal (1/10), and diagnoses were confirmed with cytokeratin and vimentin immunohistochemistry. Further research is necessary to determine true prevalence and causes of this disease in domestic and nondomestic felids and to improve antemortem diagnostic testing and treatments.

Tigers (Panthera tigris) are apex predators and vital indicators of a healthy terrestrial ecosystem. Their effective conservation demands long-term data on their populations, prey abundance, and anthropogenic disturbances from humans and domestic animals across different forest management regimes. In this study, we analyzed camera trap datasets (2009, 2013, 2018, and 2022) from Parsa National Park, its buffer zone, and adjoining national forests. Using the Relative Abundance Index (RAI), we quantified the abundance of tigers, prey, humans, and domestic animals. Our findings revealed a significant increase (χ2 = 9.6; df = 3; p < 0.05) in the RAI of tigers (from 2.65 in 2009 to 7.11 in 2022) and their prey, coupled with a decrease in anthropogenic disturbances in the national park. Meanwhile, no significant differences in the RAI of tigers and their prey were observed in the buffer zone and national forests. We also found an increasing trend of human disturbances (RAI from 351.44 in 2009 to 389.7 in 2022) in the national forests. However, the abundance of domestic animals showed a decreasing trend across all three forest management regimes. Our results suggest that a reduction in anthropogenic disturbances has a more notable positive impact on tigers' abundance than on their prey. This study emphasizes the need for directed conservation policies to reduce anthropogenic disturbances in buffer zones and national forests, while also addressing local needs and securing their goodwill for sustainable tiger conservation.

Abstract The tiger Panthera tigris is an apex predator categorized as Endangered on the IUCN Red List. The availability of sufficient prey is a key requirement for its survival. The tiger diet landscape refers to a dynamic ecological picture of the diverse prey species consumed by tigers in a specific region, reflecting the complex relationships between tiger populations and their prey. It can provide information on the tiger’s preferred prey as well as the conservation status of prey species across boundaries. To draw up a road map for the conservation and management of tigers across the Indian subcontinent, where the Bengal tiger Panthera tigris tigris occurs, we identified which prey species make up the majority of the tiger’s diet and answered questions relating to prey density, distribution and conservation status. We reviewed 48 studies published over 30 years (1992–2022) on tiger diet and prey availability. We recorded c. 30 mammalian prey species, with chital Axis axis, sambar Rusa unicolor, wild boar Sus scrofa, Tarai gray langur Semnopithecus hector, northern red muntjac Muntiacus vaginalis and domestic livestock contributing c. 90% of the total relative biomass consumed. Nearly half of the prey species are of conservation concern (categorized as Near-Threatened, Vulnerable or Endangered on the IUCN Red List), and 11 prey species are listed on CITES Appendix I. As part of a sustainable tiger conservation road map, we suggest that the tiger’s major prey species should be incorporated into government protection schemes.

Isolation and characterization of a novel feline panleukopenia virus strain from Amur tigers: Insights into pathogenesis and diagnostic development.

Plastisphere characterization and ecological implications of plastic pollution in Northeast Tiger and Leopard National Park, China.

The Amur tiger (Panthera tigris altaica) is a flagship and umbrella species of forest ecosystems in northeastern Asia. Climate change is profoundly and irreversibly affecting wildlife habitat suitability, especially for large mammals. To effectively protect the Amur tiger, it is necessary to understand the impact of climate change on the quality and the connectivity of its habitat. We used the species distribution models combined with the latest Shared Socioeconomic Pathway (SSP) climate scenarios to predict current and future changes in habitats and corridors. We found the following: (1) The total area of the Amur tiger's suitable habitat currently amounts to approximately 4941.94 km2, accounting for 27.64% of the study area represented by two adjacent national parks. Among these habitats, the highly suitable areas are mainly located on the both sides of the Sino-Russian border. The landscape connectivity remains relatively stable, and the degree of fragmentation in highly suitable habitats is low. (2) Although the suitable habitat of the Amur tiger shows an expansion trend under most climate scenarios (excluding SSP3-7.0), the area of suitable habitat within the entire study region does not increase significantly. Therefore, we should implement conservation measures to facilitate the continued expansion of suitable habitat for the Amur tiger. The quantity and length of landscape connectivity corridors are expected to vary in response to changes in core habitat patches, while the centroid of highly suitable habitats is also expected to shift to different extents. In such circumstances, new ecological corridors need to be constructed, while existing natural ecological corridors should be preserved.

ABSTRACT Wildlife corridors play a vital role in maintaining isolated populations and preserving ecosystem functionality. From February to May 2023, we conducted a camera trap study in Atei Reserve Forest, a key corridor linking Similipal and Satkosia Tiger Reserves in Odisha, India. Over 3214 trap-nights at 53 camera stations, we recorded 25 mammal species, including seven species that are threatened according to the International Union for Conservation of Nature (IUCN): tiger (Panthera tigris), leopard (P. pardus), sloth bear (Melursus ursinus), Asian elephant (Elephas maximus), gaur (Bos gaurus), sambar (Rusa unicolor), and four-horned antelope (Tetracerus quadricornis). The jungle cat (Felis chaus) was the most frequently photo-captured species, while the four-horned antelope had the widest distribution. These findings provide crucial insights for conservation planning to ensure safe wildlife movement through the corridor.

Humans and wildlife have coexisted spatially and temporally for many years. However, this is disturbed when human-induced changes constrain limited and shared resources, leading to increased competition for resources and negative human-wildlife interactions. This study aims to examine the implications of habitat changes on human-large carnivore interaction (HLCI) and identify priority areas for negative interaction. The study was conducted in the Terai Arc landscape in two study blocks constituting three wildlife corridors in the Corbett and Indo-Nepal transboundary landscapes. This study assessed the decadal changes in habitats and identified priority sites of negative interaction based on reported wildlife attacks due to Panthera tigris and Panthera pardus. The study mapped five spatial risk zones, from very low to very high, and determined the effects of habitat changes on HLCI. Changes in land-use patterns, vegetation health, and anthropogenic activity have significant effects on hotspots of negative HLCI. Our results will support decision-makers and park managers in streamlining, managing, and prioritizing local and regional mitigation efforts at the identified sites. This approach will help improve the co-existence scenario in the landscape.