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\' concept can and should be integrated into habitat management to maintain delicate predator-prey dynamics within ecosystems.

Captive large felines are prone to abnormal repetitive behaviors like pacing, which are associated with welfare issues. Visual contact without the opportunity to engage in appropriate behavior is known to increase pacing. To better understand the relationship between pacing and conspecific visual contact, we investigated this effect by conducting a barrier experiment on a male-female pair of Sumatran tigers (Panthera tigris sumatrae) in Rotterdam Zoo, the Netherlands. The tigers were exposed to four consecutive housing treatments: (i) housed in the same enclosure (baseline), (ii) housed in separate enclosures with visual contact, (iii) housed in separate enclosures without visual contact, and (iv) housed in the same enclosure after the separation. We used focal and scan sampling to measure pacing and recorded the number of visitors. Moreover, we applied scan sampling to measure activity. Overall, our results indicate that the tigers paced significantly more when housed in separate enclosures with conspecific visual contact. Moreover, our results suggest that limiting visual contact between neighboring tigers can mitigate pacing. Implementing these findings in tiger husbandry and enclosure design has the potential to improve animal welfare zoo populations of large felines.

Safe chemical immobilisation of wild felids is essential for both conservational management and clinical purposes. However, little is known about drug protocols and current practice.
This study was designed as an online survey based on a questionnaire. Descriptive/correlation statistics and analysis of proportions were used for data analysis.
The preferred immobilisation technique was the use of darts (37% of the respondents), while the most popular drug combination was a mixture of benzodiazepines, alpha-2 adrenoreceptor agonists and dissociative anaesthetics (27%). The inclusion of ketamine in the drug mixture was associated with a quicker anaesthetic onset, as estimated by the participants (p < 0.001). Common complications were prolonged recovery (46%), bradycardia (35%), hypoventilation (32%), hypothermia (26%) and arousal (26%). Commonly encountered problems were inappropriate equipment (39%), lack of suitable drugs (27%) and inadequate knowledge of species-specific pharmacology (29%) and physiology (24%).
Incomplete adherence to the Checklist for Reporting Results of Internet E-Surveys is acknowledged.
Drug protocols including both alpha-2 adrenoreceptor agonists and dissociative anaesthetics are preferred in wild felids, and the inclusion of ketamine may be useful to achieve a quick onset. Equipment/drug availability and species-specific knowledge are potential areas of improvement to improve wild felid anaesthesia.

A 12‑year‑old intact male Panthera tigris presented with pain and weight loss was euthanatized. Necroscopical examination revealed a neoplastic mass expanding to the left renal pelvis with metastatic dissemination to local lymph node, adrenal gland, and lung. Immunohistochemical characterization was performed revealing co‑expression of both cytokeratin and vimentin and negativity for both PAX8 and c‑KIT. Considering histochemical and immunohistochemical results the tumour was classified as renal cell carcinoma with metastatic spread. This report provides insights into the morphological and immunohistochemical features of renal cell carcinoma in Panthera tigris.

We report a high rate of seropositivity against SARS-CoV-2 in wild felines in India. Seropositivity was determined by microneutralization and plaque reduction neutralization assays in captive Asiatic lions, leopards, and Bengal tigers. The rate of seropositivity was positively correlated with that of the incidence in humans, suggesting the occurrence of large spillover events.

The South China tiger (Panthera tigris amoyensis, SCT) is the most critically endangered subspecies of tiger due to functional extinction in the wild. Inbreeding depression is observed among the captive population descended from six wild ancestors, resulting in high juvenile mortality and low reproduction. We assembled and characterized the first SCT genome and an improved Amur tiger (P. t. altaica, AT) genome named AmyTig1.0 and PanTig2.0. The two genomes are the most continuous and comprehensive among any tiger genomes yet reported at the chromosomal level. By using the two genomes and resequencing data of 15 SCT and 13 AT individuals, we investigated the genomic signature of inbreeding depression of the SCT. The results indicated that the effective population size of SCT experienced three phases of decline, ~5.0-1.0 thousand years ago, 100 years ago, and since captive breeding in 1963. We found 43 long runs of homozygosity fragments that were shared by all individuals in the SCT population and covered a total length of 20.63% in the SCT genome. We also detected a large proportion of identical-by-descent segments across the genome in the SCT population, especially on ChrB4. Deleterious nonsynonymous single nucleotide polymorphic sites and loss-of-function mutations were found across genomes with extensive potential influences, despite a proportion of these loads having been purged by inbreeding depression. Our research provides an invaluable resource for the formulation of genetic management policies for the South China tiger such as developing genome-based breeding and genetic rescue strategy.

BACKGROUND: Genetics driven interventions if adopted in conservation breeding projects may enhance the overall success by prioritizing breeding among genetically most competent individuals and delaying or completely diminishing the ill effects of inbreeding.
RESULTS: In the present study, we investigated genetic make-up of 15 tigers housed at five different captive facilities of West Bengal in India and report the moderate level of genetic variation. We identified five tigers based on individual genetic attributes that may be prioritized for future breeding or animal exchange programmes. The occurrence of first and second order related individuals in captivity require management attention and they should be paired considering their immediate genetic background.
CONCLUSIONS: Considering tiger as a case study, we highlight the use of genetic assessment and necessity to validate the studbook records in formulating adaptive management strategies for long-term conservation and management of species of interest.

This retrospective study identified and characterized brain lesions in captive nondomestic felids from a large cat sanctuary. Necropsy reports from January 2002 through December 2018 were examined, and gross images and microscopic slides were reviewed from individual cats, where available. In total, 255 cats met the following inclusion criteria: complete necropsy report available, brain examined grossly or microscopically, and age of >1 mon. Of the 255 cats, 49 cats (19%) were determined to have brain lesions. Eleven different felid species, as well as one captive-bred hybrid (liger), were included in the study, with tigers (Panthera tigris) (55%) and lions (Panthera leo) (18%) being the most common species. Lesions were grouped into six etiologic categories: neoplastic (32%), vascular (26%), inflammatory or infectious (20%), congenital (9%), idiopathic (7%), and metabolic (6%). Not included in these categorized lesions were previously undescribed amphophilic globules in the cerebral cortex of many cats with and without other brain lesions; these were in 95% of lion and 93% of tiger brains where the cerebral cortex was available for histologic examination. These globules were not associated with clinical disease. The histopathologic and gross brain changes documented in this study provide insight into specific diseases and pathologic processes that affect the brains of captive large cat populations.

BACKGROUND: In high-expertise transradial (TR) centers, the radiation exposure to patients during coronary angiography (CAG) is equivalent to transfemoral use. However, there is no definitive information during TR-CAG regarding the use of a single, dedicated catheter to impart less radiation exposure to patients.
OBJECTIVE: We compare the radiation exposure to patients during right TR-CAG with Tiger II catheter (Terumo Interventional Systems) vs Judkins right (JR) 4.0/Judkins left (JL) 3.5 catheters (Cordis Corporation).
METHODS: This multicenter, randomized, and prospective trial included 180 patients submitted to right TR-CAG, with the primary objective of observing radiation exposure to patients through the measurement of fluoroscopy time, air kerma (AK), and dose-area product (DAP) using Tiger II (group 1) vs JR 4.0 and JL 3.5 Judkins catheters (group 2). Secondary outcomes included contrast volume usage and the need to use additional catheters to complete the procedure (the crossover technique).
RESULTS: Group 1 demonstrated reduced fluoroscopy time (2.47 ± 1.05 minutes in group 1 vs 2.68 ± 1.26 minutes in group 2; P=.01) and non-significant reduction of AK (540.9 ± 225.3 mGy in group 1 vs 577.9 ± 240.1 mGy in group 2; P=.34) and DAP (3786.7 ± 1731.7 μGy•m² in group 1 vs 4058.0 ± 1735.4 μGy•m² in group 2; P=.12). Contrast volume usage (53.46 ± 10.09 mL in group 1 vs 55.98 ± 10.43 mL in group 2; P=.13) and the need for additional catheters (5.56% in group 1 vs 4.44% in group 2; P>.99) were similar between groups.
CONCLUSIONS: The Tiger II catheter was able to reduce radiation exposure to patients submitted to TR-CAG through a significant reduction in fluoroscopy time.

The zoos manage small populations of endangered big cat species like tiger, lion, and leopard for display, research, and conservation breeding. Genetic management of these populations is essential to ensure long term survival and conservation utility. Here we propose a simple and cost effective microsatellite based protocol for the genetic management of captive big cats. We sampled 36 big cat individuals from Seoul Grand Park Zoo (Republic of Korea) and amplified 33 published microsatellite loci. Overall, allelic richness and gene diversity was found highest for leopards, followed by lions and tigers. Twelve of the thirty-three markers showed a high degree of polymorphism across all target species. These microsatellites provide a high degree of discrimination for tiger (1.45 × 10-8), lion (1.54 × 10-10), and leopard (1.88 × 10-12) and thus can be adopted for the genetic characterization of big cats in accredited zoos globally. During captive breeding, zoo authorities rely on pedigree records maintained in studbooks to ensure mating of genetically fit unrelated individuals. Several studies have reported errors in studbook records of big cat species. Microsatellites are simple and cost effective tool for DNA fingerprinting, estimation of genetic diversity, and paternity assessment. Our unified microsatellite panel (12-plex) for big cats is efficient and can easily be adopted by zoo authorities for regular population management.