PhD Theses (WII)
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Item Study of Ecosystem Services Provided by Mountain Watersheds(Wildlife Institute of India, Dehradun, 2026) Debnath, Anindita; Talukdar, GautamEcosystem service (ES) mapping has emerged as a robust scientific approach to understanding landscape dynamics, conserving biodiversity, and sustaining nature’s contributions to people amid land-use/land-cover change and accelerating climate change. In ecologically fragile mountain systems such as the Himalaya, ecosystem services are highly sensitive yet rarely quantified for decision making. The Askot landscape, situated in the western Himalayan landscape in Pithoragarh district of Uttarakhand, covers approx. 4496.49 sq.km. Despite providing vital regulating, provisioning, and supporting services, this region has received limited integrated assessment. Addressing this gap, the present study examined long-term land-use–land-cover (LULC) dynamics, associated carbon sequestration trends, and future climate vulnerability to support evidence-based decision making. To achieve this, this study pursued three objectives: (i) to analyse spatial and temporal LULC changes, (ii) to quantify trends in above-ground carbon storage across forest and vegetation types, and (iii) to identify climatically vulnerable areas under future climate scenarios.The results reveal that nearly 10% of the Askot landscape experienced LULC change over the study period, with the most pronounced transformations occurring between 2011 and 2020, indicating an acceleration of recent landscape dynamics. Forests occupy only ~18% of the total landscape, yet they underpin a substantial share of ecosystem services. Dense forest area declined from 391.7 sq.km (1990) to 369.4 sq.km (2020), while moderate dense forest showed a sharper reduction (259.3 to 227.9 sq.km), accompanied by a marked increase in open forest (155.9 to 206.9 sq.km). This pattern reflects widespread forest degradation rather than abrupt deforestation. Scrub ecosystems also declined, while landslides more than doubled (7.45 to 15.8 sq.km), signalling growing geomorphic instability. High-elevation systems exhibited strong climate sensitivity, with alpine meadows shrinking (842.2 to 790.4 sq.km) and snow cover declining by over 100 sq.km, alongside a substantial expansion of the Moraine class (473.3 to 714.5 sq.km), indicating snowline instability and water stress, affecting another vital ES.Vegetation-type analysis further confirms degradation across major forest types. Oak-dominated systems (Quercus leucotrichophora (Banj Oak), Quercus semecarpifolia (Kharsu Oak), Quercus floribunda (Moru Oak), Betula-Abies (Birch–Fir), Deodar, Pine, and Mixed broadleaf forests all showed declines in dense and moderate canopy classes with a concurrent rise in open forest cover. Above-carbon carbon storage and sequestration show consistent declines across oak-dominated forests (Banj, Kharsu, Moru), Birch–Fir, Deodar, Pine, and mixed broadleaf systems, primarily through transitions from dense and moderate canopy classes to open forest. These structural changes directly influenced carbon dynamics. In 1990, the total AGC was estimated at 67,529.41 MgC, which declined to 66,597.79 MgC by 2020. Projections for 2050 indicate a further reduction in AGC to 66,062.30 MgC, corresponding to an additional loss of 535.49 MgC between 2020 and 2050. Total above-ground carbon stock declined from 67,529.41 MgC in 1990 to 66,062.30 MgC by 2050, representing a cumulative loss of 1,467.11 MgC over six decades. Meadows and scrub ecosystems showed the steepest proportional carbon losses, while forest carbon decline was driven largely by canopy thinning rather than loss of forest area. The relatively lower projected future carbon loss reflects the slow-changing nature of forest types, even as degradation continues.Oak forests emerge as the primary climate mitigation asset in the Askot landscape, contributing ~61% of total above-ground carbon (AGC) by 2050 despite occupying less than 10% of the total area. When combined, all forest classes (oak, temperate, and mixed forests) account for 18% of total area and contributing to approximately 85% of total AGC, clearly establishing forests as the dominant carbon pool within the watershed. This concentration of carbon within a limited forested area highlights the disproportionate importance of forests. Even marginal losses in forest cover translate into substantial carbon emissions; for instance, a 0.26% reduction in oak forest area corresponds to an estimated loss of ~105 MgC.The scope of present study was to identify climatically vulnerable ecosystems in the Askot landscape by integrating Climate-Ecological Niche Factor Analysis (CENFA). To perform this analysis, two Shared-Socioeconomic Pathways (SSP) were considered, SSP245 (Middle of the road) and SSP585 (Worst-case scenario) for mid-century (2041-2060) and end-of century (2081-2100). Climate vulnerability assessment using CENFA highlights extensive areas of medium to high vulnerability, particularly under SSP585. High-vulnerability zones increase from 1266.7 sq.km (SSP245) to 1535.2 sq.km (SSP585) in the near future, and further expand to 1762.6 sq.km by end-century, disproportionately affecting alpine, sub-alpine, and degraded forest regions. These areas spatially correlated with zones of observed LULC change and carbon decline, underscoring climate–LULC risks. Askot landscape is undergoing progressive ecological degradation driven by forest structural decline, high-elevation climate stress, and increasing disturbance. Integrating LULC dynamics, carbon assessment, and CENFA this research can support ecosystem-based adaptation leading to climate-adaptive land-use planning.Item Ecological and phylogenetic aspects of an Avian aerial Insectivore: The Barn Swallow in the Himalaya(Wildlife Institute of India, Dehradun, 2026) Kaur, AmarjeetThis thesis is a first to document the ecology of a common and widespread species yet is declining in many parts of its range, the Barn Swallow (Hirundo rustica). The species breeds in the Northern Hemisphere and undertake long-distance migratory movements every year to its non-breeding grounds in Southern Hemisphere. Owing to its close association with humans – the nature of nest building in human artefacts, the Barn Swallow is a well-known human commensal species globally. Due to its widespread distribution, populations show variations in their morphological as well as genetic traits, and globally six subspecies of H. rustica are recognized, of which two are sedentary or non-migratory. Though common, this aerial insectivore is experiencing severe population declines in Canada, North America and parts of Europe with global population trend status is declining. The widespread declines in Barn Swallow populations have alarmed the scientists across the world with the urgent need for ecological monitoring and identification of region-specific drivers of decline. In India, three out of six subspecies of Barn Swallow are reported to occur - two subspecies, H. r. rustica and H. r. gutturalis breed in Himalaya while the third H. r. tytleri is a winter visitor in Northeast India. Given the documented alarming declines across regions, population trends of Barn Swallows in India remain unknown. This formed the basis of this thesis wherein the knowledge gaps on species are addressed with three major components. First, given the absence of any population trend, eBird data - citizen-science observations was utilised to examine the species’ breeding and non-breeding distribution across the Indian subcontinent. Second, field surveys were conducted across the Himalayan region to document the breeding sites of Barn Swallows with main focus of documenting breeding ecology in the Uttarakhand Himalaya. Third, Barn Swallow populations across the Himalayan range were examined to assess morphological and genetic variations. Finally, the thesis is concluded by synthesizing ecological and evolutionary findings, while also highlighting the strong cultural relationship between Barn Swallows and the people of the Himalaya. The first objective focuses on eBird locations to document the occurrence of Barn Swallows in the Indian subcontinent. eBird platform is valuable particularly in parts of the world where long-term species monitoring programs are limited and access to ecological data remains constrained. eBird data was utilized with the objective of investigating the occurrence and seasonal movements of the Barn Swallow in the Indian Subcontinent. With five years of data (2019 – 2023), following eBird best practice criteria, checklists were filtered and considered for the analyses. Barn Swallows presence data was compiled for the Indian subcontinent region, divided into equal-area icosahedron hex grids (25 km²). For each cell, daily presence was calculated and then weighted daily mean location was calculated using the central longitude and latitude of each cell. A generalized additive model (GAM) was applied on the weighted mean daily locations for each year to model latitude and longitude separately as functions of time (Julian day). Combining the predicted latitude and longitude values from the fitted GAM, daily population-level centroids were generated. From the GAM predicted occurrence centroids, migration timing, migration speed and migration distance was calculated, and seasonal and annual variations were compared using linear regression and linear mixed models.Across five years, Barn Swallows bred at a mean latitude of 28.18°N and wintered around 16.19°N, with marked interannual variation in both breeding extent and migration timing. Spring migration began on average in late March and was faster than autumn migration (23.7 vs. 20.1 km/day), although this difference was marginal. Migration distances were similar between seasons (≈1550 km in spring; ≈1670 km in autumn). Migration timing influenced latitudinal positions, with later spring departures associated with more northerly locations and later autumn departures with more southerly positions. Weak northward shifts in migration routes and breeding latitudes were observed over time, indicating subtle directional changes in the migratory system. This eBird analysis provides the first broad-scale synthesis of Barn Swallow migration within the Indian subcontinent, revealing that Himalayan-breeding populations consistently occupy higher latitudes during breeding and overwinter predominantly in southern India, underscoring India’s central role in Asian migratory connectivity. Migration phenology showed spring departure in late March and residence at breeding sites until late July, with faster and slightly shorter spring migration compared to autumn, consistent with optimal migration theory and monsoon-driven resource tracking. Interannual variation in timing, speed, and distance likely reflects environmental variability along migratory routes. Weak but consistent northward shifts in breeding and migratory latitudes suggest early climate-driven range adjustments that may be especially consequential in the rapidly changing Himalayan landscape. Despite limitations of citizen science data, these findings establish a critical baseline for understanding the migration ecology of Himalayan Barn Swallows and highlight the need for integrated tracking and ringing studies to resolve population-specific routes, identify key non-breeding habitats, and assess future climate and land-use impacts.The second objective focuses on documenting breeding distribution and nesting ecology of Barn Swallows in the Indian Himalayan Region. Systematic surveys across the Himalayan range from west to east axis between 2019 and 2023 (excluding two years- 2020 and 2021 of COVID-19 pandemic) were carried out. On locating a nest, nest-site characteristics and nest attributes were recorded. Systematic nest monitoring was conducted across four sites in Uttarakhand to quantify breeding parameters and nest success of Barn Swallows, with nests monitored every 5–7 days from initiation to outcome. Breeding metrics including clutch size, brood size, fledgling number, and nesting duration were estimated, and nest success was assessed using both apparent success and Mayfield nest survival estimates to account for unequal exposure times. Spatial and temporal variation in nest success was analysed using binomial generalized linear models. To examine nestling diet and prey selection, faecal samples were collected from active nests and prey remains were identified to insect order using microscopy, while aerial insect availability was quantified through sweep-net sampling along foraging transects at rural and urban sites. Diet composition and prey availability were compared across settlement types using frequency of occurrence, PERMANOVA, and NMDS based on Jaccard dissimilarity, allowing assessment of dietary differences between urban and rural habitats and evaluation of prey use relative to local insect communities. Across the Indian Himalaya, 1,450 Barn Swallow nests were recorded between an elevation belt of 489 and 2,317 m, with a mean nesting elevation of ~1,500 m and high concentration within the mid-elevational range (1,000–2,000 m). Nesting records spanned 24.4–34.2°N and were unevenly distributed among states, with Uttarakhand contributing the majority of nests and exhibiting the broadest elevational range. Across the region, over 70–90% of nests were located inside buildings, most commonly on walls, bulb holders, and other artificial supports, with commercial structures such as shops dominating in most states. In Uttarakhand, breeding activity extended from late February to late June, with mean nest initiation around day 102 of the year and clear advancement in nest initiation, egg-laying, and fledging dates across years, particularly in 2023. Mean clutch size was 3.88 eggs, mean brood size 3.25 chicks, and successful nests fledged an average of 2.63 young, though reproductive output varied across sites. Apparent nest success was 62.2%, while Mayfield estimates indicated higher overall nest survival (mean 76.5%), reflecting differences in exposure time and daily survival rates among sites and years. Nest success varied significantly among regions but not among years, with Nainital and Bageshwar showing consistently higher success than Kempty. Diet analysis of 240 nestling faecal samples identified six insect orders, dominated by Coleoptera (96.7%) and Hymenoptera (75%), with significant differences in prey composition between rural and urban settlements and weaker spatial structuring within settlement types. Aerial insect sampling revealed distinct insect communities between rural and urban habitats, yet nestling diets differed significantly from local prey availability at both settlement and site levels, indicating selective foraging rather than passive prey use. This objective’s findings provide the first comprehensive assessment of Barn Swallow breeding ecology across the Indian Himalaya, demonstrating that the species is a widespread and regular breeder across a broad elevational range, with nesting concentrated at mid-elevations where it is likely that climatic conditions and prey availability are most favourable. The strong association with human-made structures - particularly indoor nesting in shops and traditional buildings - highlights the species’ long-standing commensal relationship with people in the region and complete dependence on human structures for nesting in the region. Spatial variation in breeding distribution and reproductive success appears to be driven by regional climate, monsoon dynamics, and local habitat quality, while the observed advancement in breeding phenology between 2019 and 2023 is consistent with climate-driven shifts documented in migratory birds globally. Dietary analyses revealed selective foraging, with nestlings fed predominantly large-bodied insects, especially Coleoptera and Hymenoptera, and clear differences between rural and urban settlements reflecting habitat-specific prey availability. The mismatch between available insects and prey consumed indicates active prey selection rather than opportunistic feeding, though reliance on faecal analysis may underrepresent soft-bodied taxa. Collectively, these findings underscore the vulnerability of Himalayan Barn Swallow populations to rapid changes in architecture, land use, and insect communities. The ongoing replacement of traditional buildings with sealed modern structures, combined with widespread declines in aerial insects, may create ecological traps where nesting opportunities persist but food resources do not. Conservation efforts in the Himalaya should therefore integrate nest-friendly architectural practices, protection of insect-rich foraging habitats, and long-term monitoring to safeguard this culturally valued and ecologically important aerial insectivore in a rapidly transforming mountain landscape. The third objective of the thesis is aimed to fill the gap in identity and origin of Barn Swallow populations breeding in the Indian Himalayan region. Despite well-documented morphometric variation among Barn Swallow subspecies, the identity, breeding distribution, and evolutionary history of populations breeding in the Indian Himalayan region remain poorly understood. In particular, it is unknown when Barn Swallows colonized the Himalaya, how Pleistocene glacial events shaped their present-day distribution, and how or whether geographically isolated populations - such as the sedentary population in Manipur - diverged from the largely migratory Himalayan populations. Addressing this gap, the third objective of this study investigates the phylogeography of Barn Swallow populations breeding in the Indian Himalaya within a global context, integrating Indian populations with well-studied breeding populations worldwide to elucidate their evolutionary relationships, historical connectivity, and region-specific adaptations. For this objective, adult Barn Swallows were captured at breeding sites across Kashmir, Uttarakhand, North Bengal, and Manipur using mist-nets and customized butterfly nets, and standard morphometric measurements were recorded. Birds were banded, and small blood samples were collected from adults for genetic analysis. Morphometric variation among regions was examined using principal component analysis, one-way ANOVA, and post-hoc tests, with wing length used as a proxy for body size and additional regression analyses conducted to assess latitudinal trends; sexually dimorphic tail streamers were analysed separately by sex. For phylogeographic analysis, mitochondrial Cytochrome b and ND2 gene sequences were generated from blood samples, following DNA extraction using standard kits and PCR amplification with published primers. Sequences were edited, aligned, and analysed alongside global Barn Swallow subspecies sequences retrieved from GenBank. Genetic diversity was estimated, phylogenetic relationships were reconstructed using Bayesian inference in BEAST with appropriate substitution models and outgroup rooting, and haplotype relationships were visualized using median-joining networks, with genetic distances calculated under the best-fitting evolutionary model. Barn Swallow populations across the Indian breeding range showed pronounced variation in plumage, morphology, and genetic structure. Plumage colouration varied geographically, with buff-bellied birds with broken or broad breast bands dominating Uttarakhand and North Bengal, mixed white to rufous-bellied individuals with complete breast bands in Kashmir, and predominantly rufous to chestnut-orange birds with broken or complete breast bands in Manipur. Morphometric analyses of 158 adults revealed clear regional structuring, with principal component analysis separating populations primarily along a body size axis (PC1) and a bill morphology axis (PC2), together explaining 58.6% of total variance. Birds from the Srinagar Valley were significantly larger, exhibiting the greatest wing lengths, while individuals from the Imphal Valley were smallest; Himalayan populations (Uttarakhand and North Bengal) were intermediate but showed greater variability in bill traits. Sexually selected outer tail length was consistently longer in males than females, with both male and female Kashmir birds exhibiting significantly longer streamers than those from other regions. Across all populations, wing length, tarsus length, body mass, and head length increased significantly with latitude, indicating strong latitudinal clines in body size.Phylogeographic analyses based on mitochondrial Cyt b and ND2 genes revealed two genetically distinct Barn Swallow lineages within India. All samples from Kashmir, Uttarakhand, and North Bengal clustered into a well-supported and genetically distinct Himalayan clade, whereas samples from Manipur, along with two individuals from Uttarakhand, grouped with the East Asian subspecies Hirundo rustica gutturalis. Both Bayesian phylogenetic reconstruction and haplotype network analyses consistently supported this deep genetic separation, indicating that Himalayan Barn Swallow populations represent a distinct evolutionary lineage, clearly differentiated from other recognized subspecies across the species’ global range.This study demonstrates strong geographic structuring in morphology and genetics of Barn Swallows across the Indian Himalayan region, shaped by latitude, ecology, and historical biogeography. Birds breeding at higher latitudes in Kashmir were consistently larger, with longer wings and exaggerated male tail streamers, conforming to well-established latitudinal size clines and suggesting adaptation to colder climates, migratory demands, or flight efficiency. Central Himalayan populations (Uttarakhand and North Bengal) showed intermediate morphology with greater trait variability, indicating partial phenotypic cohesion along the Himalayan axis, potentially constrained by geographic barriers such as the Pir Panjal range. In contrast, the newly documented resident breeding population in Manipur exhibited distinct plumage and smaller body size, with morphometric traits that do not align cleanly with described subspecies, instead appearing intermediate between H. r. tytleri and H. r. erythrogaster. This challenges traditional subspecies assignments in South and Southeast Asia and highlights unresolved complexity in the region’s biogeographic history. Phylogeographic analyses revealed two well-defined mitochondrial lineages within India: a distinct Himalayan clade encompassing Kashmir, Uttarakhand, and North Bengal, and an eastern lineage aligned with H. r. gutturalis that includes all Manipur samples and a small subset from Uttarakhand, suggesting secondary contact or admixture. The concordance between morphometric differentiation and genetic structure indicates that geographic isolation, local adaptation, and sexual selection may jointly reinforce divergence despite the species’ high dispersal ability. The Manipur population may have arisen through secondary colonization and introgression or through a shift from migratory to sedentary breeding within a former wintering range, underscoring the Barn Swallow’s capacity for rapid evolutionary and behavioural change. While these patterns point to the Himalaya as an important axis of divergence, the Himalayan lineage is best viewed as an incipient evolutionary or management unit rather than a fully differentiated subspecies, emphasizing the need for genome-wide data and migratory tracking to resolve evolutionary status and inform conservation in this climatically sensitive region. Thie last chapter discusses on Barn Swallows as one of the world’s most successful avian commensals, whose close association with humans emerged relatively recently alongside permanent settlements during the Holocene. Across cultures, their reliance on human-made structures for nesting has fostered deep symbolic, religious, and emotional connections, particularly in breeding regions. In the Indian Himalaya, where Barn Swallows are summer breeders nesting predominantly inside houses and shops between 1000–2000 m elevation, these cultural relationships had not previously been documented. By combining large-scale surveys with ethnographic-style interviews, this study demonstrates that Barn Swallows occupy a unique socio-ecological niche in the Himalaya, where their breeding ecology is inseparable from human tolerance, daily routines, and traditional belief systems.Survey results across the Himalayan region revealed overwhelmingly positive perceptions of Barn Swallows, reflected in vernacular names that associate the species with gods, prosperity, and domestic well-being. In Uttarakhand, residents reported nesting histories extending back several decades to over a century, strong nest-site fidelity, and widespread nest protection practices, including deliberate avoidance of disturbance. Despite threats such as competition with House Sparrows, nestling mortality from ceiling fans, and predation by domestic animals, human tolerance remained high. The COVID-19 lockdown provided a natural experiment demonstrating the strength of this relationship: even when shops were closed, many owners actively ensured access for swallows by modifying shutters or maintaining openings, allowing most nests to persist. These findings highlight cultural values as an unrecognized yet critical buffer supporting Barn Swallow breeding success in human-dominated Himalayan landscapes.However, the findings of the chapter also underscore emerging vulnerabilities. Rapid urbanisation, architectural modernisation, tourism pressure, and changing hygiene norms threaten the availability of traditional nest sites and may erode long-standing cultural tolerance. While positive perceptions remain deeply rooted across much of the Himalaya, early signs of shifting attitudes mirror trends already documented in parts of East Asia, where modernization has led to nest exclusion. Given the Barn Swallow’s near-total dependence on human structures, the persistence of culturally mediated coexistence may be as important as ecological factors for its future in the region. This chapter therefore emphasizes that conserving Barn Swallows in the Himalaya requires not only habitat and insect prey management, but also the recognition, preservation, and integration of traditional cultural values into conservation and development planning. Overall, my thesis provides the first integrated ecological, evolutionary, and socio-cultural assessment of Barn Swallows in the Indian Himalayan region, revealing the Himalaya as a key axis of divergence, connectivity, and human–wildlife coexistence within the species’ Asian range. By combining citizen-science–derived migration analyses, extensive field-based breeding ecology, detailed dietary and reproductive assessments, phylogeographic and morphometric analyses, and cultural perspectives, the study demonstrates that Himalayan Barn Swallow populations are shaped jointly by climatic gradients, historical biogeography, selective pressures linked to migration and reproduction, and an unusually strong dependence on human tolerance. The identification of a distinct Himalayan genetic lineage, the reporting of a resident breeding population in Manipur, evidence for climate-linked phenological shifts, and the documentation of culturally mediated nest persistence together underscore the species’ capacity for rapid ecological and behavioural adaptation, but also its vulnerability to accelerating environmental change. Collectively, these findings establish a critical baseline for monitoring population trajectories in India, challenge simplified subspecies boundaries in Asia, and highlight that effective conservation of this declining aerial insectivore in the Himalaya will require integrative approaches that link evolutionary history, migration ecology, insect prey documentation, urban architecture-sensitive planning, and the preservation of traditional human values that have long enabled coexistence of Barn Swallows with humans in this complex mountain landscape of the Himalaya.Item Population dynamics and breeding habitat use by colonial waterbirds nesting at the Kokkare-Bellur Community Reserve, Southern Karnataka(Wildlife Institute of India, Dehradun, 2026) Mahapatra, Aksheeta; Kumar, R. SureshItem Ecology of Himalayan brown bear (Ursus arctos isabellinus) in the Trans-Himalayan region, Ladakh (Jammu and Kashmir) India(Wildlife Institute of India, Dehradun, 2025) Khan, Niazul Hassan; Pandav, BivashThe Himalayan brown bear (Ursus arctos isabellinus) is among the rarest and most threatened large carnivores in South Asia, restricted to some of the most remote, rugged, and environmentally extreme high-altitude landscapes of the Indian Himalaya. Despite its status as a Schedule I species under the Wildlife Protection Act, 1972, and its ecological significance as a flagship carnivore, it remains one of the least studied mammals in India, owing to exceptionally low population densities, secretive behaviour, harsh climatic conditions, and the logistical challenges inherent to research in remote alpine and trans-Himalayan zones. Against this backdrop, the present thesis provides the first integrated, landscape-level scientific assessment of the species’ habitat ecology, dietary patterns, human-bear conflict dynamics, and management requirements across the Union Territory of Ladakh, with an intensive focus on the Kargil District. Synthesising extensive multi-year fieldwork, including more than 30,000 man-days of data collection, systematic occupancy surveys, remote sensing and species distribution modelling, molecular scat analysis, socioeconomic surveys, and spatial conflict mapping, this work fills critical knowledge gaps and establishes a comprehensive baseline essential for long-term conservation planning for the Himalayan brown bear in India. Ladakh, which constitutes the westernmost extension of the Tibetan Plateau, is characterised by cold-arid, high-elevation ecosystems where environmental conditions are severe and biological productivity is naturally low. The region exhibits dramatic elevational gradients, with valley floors starting around 2,500 m and peaks exceeding 7,700 m, generating a mosaic of ecological zones ranging from desert scrublands to alpine pastures. Human settlements are sparse but highly concentrated in narrow, fertile valleys sustained by glacial meltwater. Traditional agro-pastoralism is the dominant livelihood system, and extensive seasonal grazing across alpine rangelands creates strong spatial overlap between livestock, wild herbivores, and carnivores. In this socio-ecological setting, the Himalayan brown bear occupies some of the most productive pockets of western Ladakh, particularly in Kargil’s Suru, Drass, Shargole, and Zanskar valleys. These landscapes, however, are undergoing rapid change due to expanding road networks, military infrastructure, tourism growth, and energy installations, which are reshaping ecological processes and wildlife movement patterns. Within this complex backdrop, the thesis first examines, on an unprecedented landscape scale, the habitat ecology and spatial distribution of the Himalayan brown bear. Using MSTrIPES xvi digital data collection tools, the study systematically surveyed 10 × 10 km grid cells, which were further subdivided into 5 × 5 km sub-grid units, over a large geographic area and amassed 2,530 confirmed bear signs. Occupancy modelling pointed out that elevation, terrain ruggedness, distance to water, and the extent of alpine ranges are strong determinants of bear presence. Bears preferred rugged and moderately sloped areas between 3,300 m and 5,000 m, which also provided quick access to high-quality foraging grounds while also offering denning security. These findings are indicative of the habitat dependence of this species on very niche ecological conditions within an otherwise hostile landscape. Parallel habitat suitability modelling undertaken using MaxEnt showed that the core habitats of Himalayan brown bears in Ladakh are restricted to western districts and, more particularly, to the Suru-Drass-Zanskar belt. The highest suitability zones correspond to areas with productive alpine meadows, perennial water availability, and moderate temperatures, while marginal suitability is observed in the harsher eastern parts of Ladakh. Importantly, the modelling revealed that many such core habitats fall outside formal protected areas; hence, there is a need for community-based and landscape-level conservation measures. This thesis component was published in Scientific Reports (2025) with first detailed study on the habitat ecology of the Himalayan brown bear in the high-altitude region providing necessary information for future management and policy decisions. A second major component of the thesis relates to the dietary ecology of the species. Given the paucity of ecological studies in the Trans-Himalaya and the challenge of distinguishing carnivore scats in multi-carnivore landscapes, the study used non-invasive molecular techniques to confirm species identity prior to micro-histological diet analysis. Of 1,380 carnivore scats collected, 408 were identified as putative brown bear scats in the field, which was confirmed by DNA sequencing. This approach greatly enhances accuracy and secures the first molecularly verified dietary profile for the species in India. Results showed that, in the summer, Himalayan brown bears in Ladakh are predominantly herbivorous, with significant consumption of graminoids, forbs, roots, and a variety of alpine herbs, a feature of the short window of plant productivity during the brief growing season. With the approach of autumn and the senescence of natural vegetation, the proportion of animal matter increases in the diet, including marmots, small mammals, and carrion. Significantly, scats in areas with close proximity to settlements, army establishments, and tourist sites contained remains of livestock and anthropogenic garbage, notably plastic. Such dependence on human-derived food sources is a cause for concern, as this may lead to altered behaviour and increasingly conflictive situations. There was spatial variation in diets, where bears inhabiting high-quality rangelands predominantly depended on natural vegetation, whereas bears inhabiting human-dominated landscapes supplemented their diet with garbage, livestock, and stored items of food. These findings not only bring out the ecological constraints for the species but also indicate the importance of proper waste disposal and livestock management in mitigation of negative human-brown bear interactions.The third important element is the dynamics and drivers of human-brown bear conflict in Ladakh, particularly in Kargil, where the species' range overlaps considerably with human-use areas. Analysis of 22 years of official conflict records, from 2001 to 2022, indicates a sharp and sustained rise in conflict incidents: only two to four incidents were reported annually during the early 2000s, suggesting negligible interactions between humans and bears. However, incidents showed a gradual rise after 2008, increasing to 11-60 cases annually between 2010 and 2014, and crossing 90 cases annually after 2015. The number of incidents reached its peak of 112 in 2021. Livestock depredation has followed an equally disturbing upward trend, with negligible losses before 2005 but rising thereafter sharply to unprecedented levels in the years 2016-2018, when annual livestock losses reached between 447 and 737 animals. Cattle were the most frequently affected livestock species, followed by horses, goats, and sheep. Overall, estimated economic losses have ranged at over INR 9.3 lakh annually, affecting vulnerable agro-pastoral households disproportionately. Spatial analysis of incidents suggested a high clustering of hotspots, especially in Drass, Suru, and parts of Zanskar, with concentrated settlements, extensive livestock grazing, waste availability, and proximity to bear habitats. Most incidents occurred in summer and autumn months, coinciding with the peak activity season of bears and reduced availability of natural forage. Household surveys across multiple valleys revealed that while fear of bears is widespread, general attitudes toward the species are positive, with a large proportion of respondents supportive of its conservation. However, rising economic losses and property damage threaten to erode tolerance, and timely and focused interventions are critical for preserving coexistence. Guided by these ecological, dietary, and social insights, this thesis proposes an integrated set of evidence-based conservation and management recommendations tailored to the unique socio-ecological context of Ladakh. The conservation of the habitat needs to prioritise the core bear habitats in Drass, Suru, Rangdum, Shargole, and Zanskar, including their designation as Community Reserves, besides implementing effective ecological impact assessments for new infrastructure projects. Degraded alpine pastures and riparian zones need restoration. Connectivity needs to be maintained through landscape-level planning. Management of food resources should include strict protocols for carcass disposal, installation of bear-proof waste bins, and improved storage facilities for crops and fodder to reduce attractants. Mitigation of conflicts needs to include predator-proof corrals, solar deterrent systems, early-warning networks, rapid response teams, and streamlined compensation schemes that incentivise preventive measures. Besides all the above, there is a very high potential for community-based ecotourism to serve as an alternative livelihood and conservation incentive based on successful models from other Himalayan regions. Ultimately, the development of collaborative governance among wildlife authorities, local communities, panchayats, pastoral groups, and tourism stakeholders must strike a balance between the demands of development and ecological sustainability. Overall, the present thesis undertakes the most comprehensive and integrated ecological assessment of the Himalayan brown bear in India and provides a science-based platform for conserving this threatened species in one of the world’s most challenging and changing high-altitude landscape.Item Study on waterbird assemblages of the Middle Ganga river(Wildlife Institute of India, Dehradun, 2025) Aftab; Mathur, V.B.; Hussain, S.A.The Ganga River, one of Asia's most biodiverse riverine systems, exemplifies this ecological significance, hosting a rich assemblage of aquatic species, including over 150 waterbird species, and threatened taxa such as the Gangetic River dolphin, gharial, and Indian skimmer. However, these ecosystems face severe threats from climate change, habitat degradation because of anthropogenic activities, including unsustainable development, and pollution, leading to an estimated 10,000– 20,000 freshwater species being extinct or at risk of extinction globally. In India, the Ganga River is significantly impacted by the over-extraction of water from dams and barrages, industrial and sewage effluents, sand mining and riverbed agriculture, resulting in significant biodiversity loss. Waterbirds are key indicators that reflect the health of wetland and riverine ecosystems, owing to their sensitivity to environmental changes. Their roles as pollinators, seed dispersers, predators, and nutrient cyclers emphasise their ecological importance. In the Gangetic plains, waterbirds rely on the dynamic hydrological processes of rivers and associated wetlands for feeding, breeding, and roosting. Yet, these habitats are under immense pressure from urbanisation, agriculture, and pollution, with up to 40% of India's wetlands lost over the past 50 years. The middle stretch of the Ganga River, supporting rich diversity of waterbirds and other aquatic fauna, remains understudied, with limited comprehensive data on waterbird assemblages and their responses to a range of environmental and anthropogenic factors. This PhD thesis investigates the spatio-temporal patterns of waterbird assemblages along the middle stretch of the Ganga River, aiming to address critical knowledge gaps in their status, distribution, and ecological dependencies. The study pursues four key objectives: (1) to determine the status, distribution, and assemblage patterns of waterbirds; (2) to identify habitat features governing waterbird assemblages; (3) to assess the impacts of anthropogenic pressures; and (4) to prioritise areas for waterbird conservation. Through systematic surveys and ecological assessments, this research seeks to generate comprehensive data on waterbird diversity and evaluate the influence of habitat characteristics, such as channel depth and width, bank features, and water quality, alongside anthropogenic stressors like sand mining, solid waste dumps, pollution, and habitat fragmentation.Item Ecology of major Invasive Alien plant species (IAPs) across various habitats in Pakke Tiger Reserve, Arunachal Pradesh(Wildlife Institute of India, Dehradun, 2026) Singh, Huidrom Bablin; Adhikari, B.S.Proliferation of invasive alien plant species poses a significant threat to the structure and function of ecosystems, making this a critical area of focus within the scientific communities. These species cause extensive damage to the biodiversity, as they are capable of altering the ecosystems and outcompete the native biodiversity. Globally, their abundance has increased dramatically in forested and other natural areas due to rapid economic growths and anthropogenic activities. To counter this alarming situation, understanding the distribution pattern, climatic influences on phenophases and ecological impact on soil by invasive alien plant species is a priority. In northeast India, studies on invasive alien plant species diversity and their impacts are very limited, especially in Arunachal Pradesh. Therefore, the present study aims to determine the patterns of distribution, phenophases and physiochemical impacts by the dominant invasive alien plant species in five forest types (Assam Alluvial Plain Semi Evergreen Forest-AAPSEF, East Himalayan Mixed Coniferous Forest-EHMCF, East Himalayan Subtropical Wet Hill Forest-EHSTWH, Non-Forest-NF and Riverine Forest-RF) of Pakke Tiger Reserve, Arunachal Pradesh. The altitudinal range of Pakke Tiger Reserve is 150- 2050 m above the sea level (490 to 6725 feet), with an average annual rainfall of 2500 mm. The current study reveals a total of 43 invasive alien plant species in the study area. However, their species richness in five forest types was in declined trend with the increase of elevation. Across the forest types, AAPSEF (30%) display the maximum level of invasion and least incursion in EHSTWHF (16%) in the current study. Among the nine species selected for the study, Chromolaena odorata (L.) R.M.King & H.Rob. was found dominant and distributed extensively in all forest types, with highest relative density (51%) in EHSTWHF and relative abundance (10%) in NF. The entire selected species shows contagious distribution pattern (<0.5) in all forest types except for Urena lobata in NF displaying random distribution (0.025 - 0.5) in study area. Ageratum conyzoides L., Chromolaena odorata (L.) R.M.King & H.Rob. and Urena lobata L. are the species with extensive distribution in all forest types in comparison to other selected species showing their dominance over the native vegetation. Moreover, maximum area cover percentage was exhibit by Chromolaena odorata (L.) R.M.King & H.Rob. followed by Ageratum conyzoides L., Mikania micrantha Kunth and Urena lobata L. across the forest types in Pakke Tiger Reserve. Forest types such as AAPSEF, NF and RF display high level of disturbances while the EHMCF and EHSTWHF have fewer incursions by invasive alien plant species in the study area. Phenological pattern on the selected species shows that Bidens pilosa L. has the longest flowering phenophases while Chromolaena odorata (L.) R.M.King & H.Rob. has the maximum fruiting duration in EHSTWHF. For leaf fall and initiation, Urena lobata L. display the longest duration in RF. Moreover, coefficient of variation shows that most of the species display asynchronous phenophases across the forest types of Pakke Tiger Reserve. Repeated measures of ANOVA also display that Ageratum conyzoides L. display difference in flowering in NF and EHSTWHF while Chromolaena odorata (L.) R.M.King & H.Rob. leaf initiation show difference in EHMCF. Correlation and linear regression display influences of climatic parameters i.e., precipitation, relative humidity, minimum and maximum temperature to the selected species in the study area. CCA also indicates that precipitation, minimum and maximum temperatures directly influence the phenophases of the selected species. However, relative humidity influences the phenophases of the selected species when in cohesion with other climatic parameters. Ecological impact on native species by invasive alien plant species was determined by collecting the soil sample of the most dominant species i.e., Chromolaena odorata (L.) R.M.King & H.Rob. across the forest types in Pakke Tiger Reserve. The result shows that clay and copper contents were high in all invaded sites while soil pH, sand, boron and water holding capacity were significantly lower in invaded plots. Out of 16 soil variables, T-test reveals that AAPSEF and NF have variation in 13 variables while EHMCF, EHSTWHF and RF have difference in 12 variables. ANOVA between the invaded and uninvaded sites also indicates significant differences in Boron, iron, copper, nitrogen, water holding capacity, clay, silt and sand. Moreover, correlation shows eight of the variables display relation between them. Furthermore, PCA indicates that INNF soil properties were different from the remaining sites. The results indicate that Chromolaena odorata (L.) R.M.King & H.Rob. alter the soil properties of invaded areas by improving the fertility, making it ideal for the proliferation process in future scenarios.Item Species diversity and molecular study of bees (Bombus and Xylocopa) in Dehradun District, Uttarakhand, India(wildlife Institute of India, Dehradun, 2025) Abha PurohitPollinators are fundamental to the functioning of terrestrial ecosystems, as they facilitate the reproduction of a vast majority of flowering plants and thereby sustain biodiversity and ecological stability. Globally, an estimated 87.5% of flowering plants depend onanimal pollinators for successful reproduction (Ollerton et.al. 2011). In addition to their ecological role, pollinators, particularly bees, are indispensable for global agriculture. Approximately 75% of the world’s leading food crops rely on pollination to enhance both yield and quality (Klein et.al. 2007). Agricultural commodities such as fruits, vegetables, nuts, oilseeds, and spices are especially dependent on bee-mediated pollination. Beyond agricultural productivity, pollinators provide critical services that directly influence human nutrition. By increasing the diversity, availability, and quality of nutrient-rich foods, they indirectly contribute to balanced diets enriched with vitamins, antioxidants, and essential micronutrients (Eilers et.al.2011). Thus, pollinators not only underpin biodiversity but also strengthen food security and human well-being, highlighting their ecological, agricultural, and nutritional significance. 2. Research objectives The study aims to conduct a systematic survey of Bombus (bumblebees) and Xylocopa (carpenter bees) in the Dehradun district, focusing on their taxonomy, ecology, and seasonal distribution in different habitat zones. It also seeks for identification and characterization of their habitats, with emphasis on the availability of food plants that sustain high species diversity. Molecular tools, including DNA barcoding, was applied for accurate identification of collected specimens. Additionally, the research evaluated the impact of anthropogenic pressures and other environmental threats on the survival and diversity of these pollinator groups in the study area.Item Assessment of altered land use pattern on the middle Ganga river hydrodynamics using Geospatial modelling(Wildlife Institute of India, Dehradun, 2025) Ali, Zeeshan; Hussain, S.A.Item Molecular Phylogeny and Population genetic structure of Himalayan Blue sheep (Pseudois nayaur) in Himalayan region(Wildlife Institute of India, Dehradun, 2025) Saini, Deepesh; Vishnupriya, K.; Gupta, S.K.; Sathyakumar, S.The Himalayan blue sheep (Pseudois nayaur), commonly known as bharal, is a high-altitude caprine species endemic to the rugged terrains of the high Himalayas. Although classified as a species of "Least Concern" by the International Union for Conservation of Nature (JUCN), significant ambiguities persist regarding its taxonomic delineation and population structure. These uncertainties are further compounded by the paucity of comprehensive genetic data, particularly concerning populations within the Indian Himalayan Region (IHR), where geographical isolation and environmental heterogeneity may have promoted evolutionary divergence. The present study aims to elucidate the phylogenetic relationships, genetic diversity, and population structure of Pseudois nayaur across its Indian range, with a specific focus on populations inhabiting the eastern and western Himalayas. Employing a molecular phylogenetic approach, this investigation integrates mitochondrial DNA (mtDNA) markers-principally the cytochrome b gene, control region and the complete mitogenome-with nuclear microsatellite markers to assess lineage differentiation, historical demography, and gene flow. Non-invasive and ethically compliant sampling strategies were utilized to obtain biological material, ensuring minimal disturbance to wildlife. Laboratory analyses, including DNA extraction, polymerase chain reaction (PCR) amplification, and sequencing, were followed by bioinformatic assessments using tools such as DnaSP, Arlequin, STRUCTURE, BEAST, and PopART. Phylogenetic reconstructions revealed distinct mitochondrial haplotypes between eastern and western Himalayan populations, suggesting limited gene flow and historical isolation likely driven by topographic and climatic barriers. The genetic differentiation observed was consistent with the theory of allopatric divergence facilitated by the orogenic and glacial history of the Himalayas. Furthermore, the study confirms the phylogenetic placement of Pseudois nayaur within the subfamily Caprinae, identifying close evolutionary affinities with Ovis and Hemitragus species while supporting its unique lineage status. These findings have important implications for conservation biology, as they suggest the existence of evolutionarily significant units (ESUs) that merit region-specific management interventions. The bharal's role as a herbivore and primary prey for apex predators such as the snow leopard (Panthera uncia) further underscores its ecological significance in alpine ecosystems.Item An ecological study on nesting patterns and Behavioural dynamics of vultures in Kangra valley, Himachal pradesh(Wildlife Institute of India, Dehradun, 2025) Bhattacharya, MalyasriVultures are nature’s most efficient scavengers, playing a critical role in maintaining ecological balance. Their populations in India have suffered a drastic decline from 97-99% between 1993 and 2002, leading to the establishment of captive breeding programs aimed at species recovery. Threats of decline have now stabilized, but little is known about the ecology and survival of the vultures in the wild, necessitating this study for the conservation of vultures in their natural habitat. Kangra Valley, situated in the westernmost region of Himachal Pradesh state in India, is one of India's important vulture sites, supporting most of the nine vulture species recorded in the country. Among these, the White-rumped Vulture (Gyps bengalensis), Egyptian Vulture (Neophron percnopterus), Bearded Vulture (Gypaetus barbatus), Himalayan Griffon (Gyps himalayensis), and Eurasian Griffon (Gyps fulvus) are the most observed, while the Cinereous Vulture (Aegypius monachus), Red-headed Vulture (Sarcogyps calvus), Slender-billed Vulture (Gyps tenuirostris), and Indian Vulture (Gyps indicus) are recorded occasionally. Kangra is also one of the most densely populated districts of Himachal Pradesh, with an extensive road network, contributing to anthropogenic pressures on vulture populations. While the region has a long history of vulture census efforts, aspects of their breeding ecology remain poorly understood. Why do they select a particular tree for nesting? What are the variables that affect nest site selection? What is the nest success rate? Where do they move, and what is their home range? What are the threats? This study, conducted between 2019 to 2024, focuses on the breeding ecology of White-rumped Vultures in Kangra, examining their nesting preferences, reproductive success, threats to nesting colonies and spatial movements. Additionally, the research explores the climatic niche availability for all nine vulture species found in the region, assessing current and future climatic scenarios to predict potential habitat suitability. The Chir Pine forests of Kangra serve as the breeding habitat for White-rumped Vultures in the region. The breeding season of the White-rumped Vulture (Gyps bengalensis) in the area extends from November to April, encompassing mating, incubation, hatching, and fledgling development, lasting approximately 25-28 weeks (October—April). Over three consecutive breeding seasons (2021-2024), the study recorded 17 active nesting colonies with a total of 617 active nests, primarily in Chir Pine (Pinus roxburghii) trees. Nest site selection was influenced by tree characteristics, with vultures preferring trees with a larger girth at breast height (GBH) (average GBH of 254.8 cm + 49.3 SD), lower canopy cover (5-10%), greater shrub density (77-100%), and proximity to other nesting trees and water sources. Conversely, areas with high fire activity, dense canopy cover, and limited nearby trees were found to be less suitable. In addition to breeding ecology, the study identified 36 carcass dumping sites in the region. These sites, managed by local communities, serve as designated areas for livestock carcass disposal, primarily for cattle and buffalo. The carcasses are transported from households to the dumping sites by local cobblers, locally known as "Harijans." The decline of open carcass disposal areas has posed further challenges for vulture populations. To understand movement patterns, five wild White-rumped Vultures were satellite-tagged in Kangra, Himachal Pradesh, in 2021. The tagged individuals exhibited extensive movements, ranging across Jammu & Kashmir, the Pakistan border near Punjab, and Uttarakhand. Three of these vultures have consistently nested in Dolba and Lapiana within Kangra between 2021 and 2024. The study recorded an average home range of 1367.6 km? for non-breeding individuals and 1719.8 km? for breeding individuals across seasons. The future distribution for the nine vulture species shows a significant decline in the modeled climatic niche for seven vultures by 2041-2060 and 2061-2080. The study identified electrocution, forest fires and poisoning as major threats, with notable vulture fatalities recorded. Major forest fire-prone areas include Gopalpur, Pathiar Range, Lunj, and Baranj Sirmani. This study offered insights into India's largest documented aggregation of 617 White-rumped Vulture nests. The study recommends targeted conservation interventions to ensure the long-term survival of White-rumped Vultures. These include the protection of nesting sites, preservation of old-growth forests, and support for cobbler communities engaged in carcass disposal. Additionally, designated vulture feeding stations within forested areas should be established. Given these findings, the study proposes designating the region as a Vulture Safe Zone, suitable areas for releasing captive-bred vultures with continuous monitoring. Himachal Pradesh Forest Department (HPFD) and the Ministry of Environment and Climate Change (MoEFCC) have to come up with guidelines to declare a vulture safe zone as well as a strategic conservation plan to safeguard this critically endangered species.