Biology subjects

Pandav, B.

Publications and source records attributed to Pandav, B..

10 recordsLinked to original sources

bioRxiv2026

Landscape-scale grassland structural heterogeneity and disturbance regimes influence swamp deer habitat utilisation across the upper Gangetic plains, India

Large herbivores play a vital role in shaping grassland ecosystems, yet many species face increasing threats from habitat loss, fragmentation, and human disturbance. In northern India, riverine grasslands of the Gangetic floodplains serve as essential habitats for such species, including the swamp deer (Rucervus duvaucelii duvaucelii), a habitat specialist that has experienced severe population declines, especially outside protected areas. We evaluated the structural vegetation composition of grasslands and swamp deer habitat use along the Ganges river, covering both protected regions (Jhilmil Jheel Conservation Reserve and Hastinapur Wildlife Sanctuary) and surrounding non-protected grasslands. Combining field-based vegetation surveys with NDVI-based remote sensing enabled the classification of grasslands into four ecologically significant types structured by Saccharum, Phragmites, and Typha species. Disturbance was prevalent across the landscape, with approximately 77% of grassland plots exhibiting signs of human impact. Pure Saccharum grasslands exhibited the highest disturbance levels, followed by mixed patches, while Phragmites-Typha patches showed the lowest disturbance. Conversely, Phragmites-Typha patches experienced the lowest levels of disturbance. Data from surveys and two radio-collared swamp deer indicated a consistent preference for mixed vegetation types, particularly Saccharum-dominated and Phragmites-Typha mixes, while avoiding heavily disturbed pure Saccharum patches. Seasonal changes in habitat use reflected context-dependent selection influenced by vegetation structure, hydrology, and disturbance regimes. Our results underscore the importance of conserving diverse grassland mosaics and reducing human pressures, especially in unprotected areas to promote the long-term survival of swamp deer and other grassland herbivores within the Gangetic floodplains.

ecology↗

bioRxiv2023

Functional connectivity in northern swamp deer (Rucervus duvaucelii duvaucelii) population across a fragmented, human-dominated landscape along Gangetic Plains of north India: Implications for conservation in non-protected areas

The Indian subcontinent has witnessed disproportionate declines in large mammalian herbivore communities. The northern swamp deer (Rucervus duvaucelii duvaucelii) exemplifies the conservation challenges of typical non-protected area species, where apart from distribution status other ecological information is limited for the upper Gangetic basin population. We combined elements of radio-telemetry and conservation genetics to evaluate dispersal patterns, population connectivity and assess genetic variation and inbreeding status of this population living across a highly human-dominated area. We genetically identified 266 unique swamp deer and further analyses revealed presence of two spatially-admixed genetic lineages with moderate heterozygosity (Ho=0.51, SD= 0.10) and low inbreeding (FIS=0.133) status. Multi- disciplinary evidence suggests that the small, isolated grassland patches between Jhilmil Jheel Conservation Reserve (JJCR) and Hastinapur Wildlife Sanctuary (HWLS) are highly preferred by swamp deer during migrations and are genetically connected. The southern part of the area in HWLS showed early signatures of genetic discontinuity that require immediate conservation attention. We hypothesized that the human settlement history of this landscape, river dynamics and species ability to negotiate various pressures and disperse has helped to maintain such connectivity. While these signatures are encouraging for this small, isolated cervid population, careful management interventions are required to ensure the integrity and functionality of this landscape. We recommend a scientifically robust population estimation approach across this landscape and a multi-stakeholder-driven strategies to augment population and habitat recovery, plantation and riverscape management to ensure long-term survival of this species.

ecology↗

bioRxiv2022

The cost of sympatry: spatio-temporal patterns in leopard dietary and physiological responses to tiger competition in Rajaji Tiger Reserve, India

1.O_LIApex predators have critical roles in maintaining the structure of ecosystem functioning by controlling intraguild subordinate populations. Such dominant-subordinate interactions involve agonistic interactions including direct (death/displacement) or indirect (physiological and/or health implications) impacts on the subordinates. As these indirect effects are often mediated through physiological processes, it is important to quantify such responses for better understanding of population parameters. C_LIO_LIWe used a well-known sympatric large carnivore intraguild system involving tiger (Panthera tigris) and leopard (Panthera pardus) to understand the dietary and physiological responses under a spatio-temporal gradient of tiger competition pressures in Rajaji Tiger Reserve (RTR), a major source tiger population of the western Terai-Arc Landscape, India between 2015-2020. The park provided a natural experimental set-up for tiger competition with the eastern part (ERTR) having high tiger density and the western (WRTR) part with functionally no competition from tigers. C_LIO_LIWe conducted systematic faecal sampling in the winters of 2015 and 2020 from ERTR and WRTR to assess diet and physiological measures. Analyses of leopard-confirmed faeces suggest a dietary-niche separation as a consequence of tiger competition. In 2020, we found increased occurrence of large-bodied prey species without tiger competition in WRTR. Physiological measures followed the dietary responses where leopards with large-sized prey in diet showed higher fT3M and lower fGCM measures in WRTR. In contrast, ERTR leopards showed lower levels of fT3M as well as fGCM in 2020, possibly due to intense competition from tigers. Overall, these pattens strongly indicate a physiological cost of sympatry where competition with dominant tigers resulted in elevated nutritional stress. C_LIO_LIThe combination of the natural habitat providing unique experimental setup, spatio-temporal sampling strategy and multidisciplinary approaches provide critical conservation perspectives for leopards, particularly in the context of recent increase in tiger numbers across India. We recommend expansion of leopard monitoring and population estimation efforts to buffers, developing appropriate plans for human-leopard conflict mitigation and intensive efforts to understand leopard population dynamics patterns to ensure their persistence during the ongoing Anthropocene. C_LI

physiology↗

bioRxiv2022

What drives prey selection? Assessment of tiger food habits across the Terai-Arc landscape, India

Large carnivores strongly shape ecological interactions within their respective ecosystems, but experience significant conflicts with human across their range due to their specific ecological resource requirements. The tiger (Panthera tigris) typifies the challenges faced by the large carnivore communities globally. India retains majority of the global tiger population with significant numbers outside protected areas (PAs) that are involved in conflicts from livestock predation and human/tiger death. To understand the prey selection patterns and spatio-temporal patterns of livestock predation-related conflict issues we investigated tiger food habits across the Indian part of the Terai-Arc Landscape (TAL), a globally-important tiger conservation landscape in India. We used 510 genetically-confirmed tiger faeces collected across the landscape and ascertained 10 wild and livestock as major prey species. Large-bodied species (sambar, swamp deer, nilgai, chital, wild pig and livestock) comprised ~94% of tiger diet, with sambar, chital and livestock were the major prey species. Habitat-specific (Shivalik-Bhabar and Terai) analyses show significantly different pattern of prey selections determined by abundance and prey body weight. Results also suggest that PA and non-PAs of Terai habitat are more prone to livestock depredation-related conflicts, and careful management interventions and community involvements are required to reduce such threats. We suggest long-term plans including population estimation of tigers and prey outside PAs, reducing grazing pressures and cattle enumeration, detailed investigation of tiger deaths etc. to ensure future tiger sustainability across this habitat.

ecology↗

bioRxiv2021

Waning grasslands: a quantitative temporal evaluation of the grassland habitats across human-dominated upper Gangetic Plains, north India

Grassland habitats currently face severe anthropogenic exploitations leading to cascading effects on the survival of grassland-dependent biodiversity globally, particularly in non-protected areas. Significant amount of such biodiversity-rich grasslands in India are found outside protected areas but lack quantitative information on their status. We evaluated the current and historical (30 years) status of the grasslands using a combination of intensive field surveys and GIS tools across one of the most fertile, human-dominated region: the upper Gangetic Plains of north India. On-ground mapping and visual classifications revealed 57% decline in grassland habitats between 1985 (418 km2) and 2015 (178km2), mostly driven by conversion to croplands (74% contribution). Radio-telemetry data from the largest endemic cervid swamp deer (n=2) showed grassland-dominated average home range (50% BBMM) size of 1.02 km2. The animals highly preferred these patches (average Ivlevs index- 0.85) and showed highest temporal continuity (88%) compared to other LULC classes. Camera trapping within the core habitats suggests critical use of these patches as fawning/breeding grounds. Habitat suitability analysis indicates only [~]18% of the entire area along Ganges is suitable for swamp deer. Accurate mapping (86% accuracy) and characterization of four major grass species revealed a total 144.04 km{superscript 2} vegetation area, dominted by Saccharum sp. (35%). We recommend protection and recovery of these critical grassland patches to maintain dynamic corridors and other appropriate management strategies involving multiple stakeholders to ensure survival of this critical ecosystem. Such evaluations, if spatially expanded, would be critical to restore this rapidly vanishing ecosystem worldwide.

ecology↗

bioRxiv2020

Effects of faecal inorganic contents in accurate measures of stress and nutrition hormone in large felines: implications for physiological assessments in free-ranging animals

Non-invasive stress and nutritional hormones and their interactions are increasingly being used to monitor psychological and nutritional physiology in free-ranging animals at different ecological scales. However, a number of extrinsic and intrinsic factors including hormone-inert dietary materials, inorganic matters etc. are known to affect accurate hormone measures. Here we addressed the impacts of inorganic matter (IOM) on corticosterone and T3 measures in wild tiger (n=193 from Terai Arc landscape, India) and captive lion (n=120 from Sakkarbaug Zoological Garden, Gujarat, India) faeces and evaluated possible corrective measures. The wild tiger samples contained highly variable IOM content (9-98%, mostly with >40% IOM) compared to captive Asiatic lion (17-57%, majority with <40% IOM). We observed significant negative correlation between IOM content and tiger GC (r=-0.48, p=0.000) and T3 (r=-0.60, p=0.000) measures but not in captive lions (r=-0.05, p=0.579). Two corrective measures viz. removing samples with [≥]80% IOM and subsequently expressing concentrations as per gram of organic dry matter (instead of total dry matter) reduced IOM influence on tiger GC and T3 measures without affecting lion GC results. The corrective measures bring out alterations in the tiger T3 results but no changes in GC results. As faecal IOM content is associated with specific behaviours of many carnivore species, our results emphasize the need to reduce IOM-driven hormone data variation for ecologically relevant interpretations for species conservation.

physiology↗

bioRxiv2020

Assessing tiger corridor functionality with landscape genetics and modelling across Terai-Arc Landscape, India

India led the global tiger conservation initiatives since last decade and has doubled its wild tiger population to 2967 (2603-3346). The survival of these growing populations residing inside the continuously shrinking habitats is a major concern, which can only be tackled through focused landscape-scale conservation planning across five major extant Indian tiger landscapes. The Terai-Arc landscape (TAL) is one of the global priority tiger conservation landscapes holding 22% of the countrys wild tigers. We used intensive field-sampling, genetic analyses and GIS modelling to investigate tiger population structure, source-sink dynamics and functionality of the existing corridors across TAL. Genetic analyses with 219 tigers revealed three low, but sigficantly differentiated tiger subpopulations. Overall, we identified Seven source and 10 sink areas in TAL through genetic migrant and gene flow analyses. GIS modelling identified total 19 (10 high, three medium and six low conductance) corridors in this landscape, with 10 being critical to maintain landscape connectivity. We suggest urgent management attention towards 2707 sq. km. non-protected habitat, mitigation measures associated with ongoing linear infrastructure developments and transboundary coordination with Nepal to ensure habitat and genetic connectivity and long-term sustainability of tigers in this globally important landscape.

ecology↗

bioRxiv2020

Sequencing and annotation of the endangered wild buffalo (Bubalus arnee) mitogenome for taxonomic and hybridization assessment

The wild water buffalo (Bubalus arnee) is one of the most endangered and least studied large bovid in the Indian subcontinent. India retains 90% of the global population as two fragmented populations in Assam and Chhattisgarh, both threatened by habitat loss and degradation, hunting, disease from livestock, and hybridization with the domestic buffalos. For the first time, we sequenced the 16,357 bp long mitogenome of pure wild water buffalo from both populations. The annotated genes included 13 protein-coding genes, 22 tRNA, two ribosomal genes, and a non-coding control region. Comparative mitogenome analyses showed both populations are genetically similar but significantly different from domestic buffalo. We also identified structural differences in seven tRNA secondary structures between both species. Both wild and domestic water buffalo formed sister clades which were paraphyletic to genus Bos. This study provides baseline information on wild buffalo mitogenome for further research on phylogeny, phylogeography and hybrid assessment and help conserving this endangered species.

molecular biology↗

bioRxiv2019

Genetic analyses reveal population structure and recent decline in leopards (Panthera pardus fusca) across Indian subcontinent

Large carnivores maintain the stability and functioning of ecosystems. Currently, many carnivore species face declining population sizes due to natural and anthropogenic pressures. The leopard, Panthera pardus, is probably the most widely distributed and adaptable large carnivore, still persisting in most of its historic range. However, we lack subspecies level data on country or regional scale on population trends, as ecological monitoring approaches are difficult to apply on such wide-ranging species. We used genetic data from leopards sampled across the Indian subcontinent to investigate population structure and patterns of demographic decline. Our genetic analyses revealed four distinct subpopulations corresponding to Western Ghats, Deccan Plateau-Semi Arid, Shivalik and Terai region of north Indian landscapes, each with high genetic variation. Coalescent simulations with 13 microsatellite loci revealed a 75-90% population decline in between 120-200 years ago across India, possibly human induced. Population-specific estimates of genetic decline are in concordance with ecological estimates of local extinction probabilities in four sub-populations obtained from occupancy modelling of historic and current distribution of leopards in India. Our results confirm population decline of a widely distributed, adaptable large carnivore. We re-iterate the relevance of indirect genetic methods for such species, and recommend that detailed, landscape-level ecological studies on leopard populations are critical to future conservation efforts. Our approaches and inference are relevant to other widely distributed, seemingly unaffected carnivores such as the leopard.

genetics↗

bioRxiv2019

A practive faeces collection protocol for multidisciplinary research in wildlife science

Faecal samples have become important non-invasive source of information in wildlife biology and ecological research. Despite regular use of faeces, there is no universal protocol available for faeces collection and storage to answer various questions in wildlife biology. We collected 1408 faeces from ten different species using a dry sampling approach, and achieved 94.87% and 86.02% success rate in mitochondrial and nuclear marker amplifications. We also suggest a universal framework to use the same samples for different use. This protocol provides an easy, quick and cheap option to collect non-invasive samples from species living at different environmental conditions to answer multidisciplinary questions in wildlife biology.

ecology↗