Theses and Dissertations

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Start date: 2020Subject: search.filters.subject.Human impact

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    Heat Hardening and the Influence of Thermal Heterogeneity of Habitat on Aboveground Activity in Spiny-tailed Lizard (Saara hardwickii)
    (Wildlife Institute of India, Dehradun, 2025) Vassa, Chirag Nimish; Dutta, Sutirtha; Kher, Varun
    Human induced climate change has challenged the persistence of many organisms at different biotic levels and alter their interaction with the environment. Ectotherms are particularly vulnerable to anthropogenic climate change due to their reliance on external environment for various life history traits. Thermoregulatory behaviour is often used by many ectotherms especially reptiles to regulate their body temperature and will be crucial in imminent future with intensification of climate change. Although behavioural thermoregulation is widely studied, but studies looking at influence of thermal heterogeneity of a habitat on aboveground activity is limited. Moreover, with escalation in global warming ectotherms might have to rely on another mechanism in addition to thermoregulatory behaviour to combat the effect. One such physiological mechanism is heat hardening a quick response to thermal tolerance that temporarily enhances thermal tolerance, allowing lizards to withstand greater temperatures for a short period. Despite its importance very limited data is available for heat hardening capacity in reptiles. This study examined the influence of thermal heterogeneity of a habitat on aboveground activity in spiny-tailed lizard (Saara hardwickii) and assessed their heat hardening capacity. Additionally, trade-off hypothesis was also tested which has been recently proposed to explain the dynamics of thermal tolerance plasticity. I found positive influence of habitat heterogeneity on aboveground activity of the lizard. However, individuals in both the conditions spent similar amount of time in different behaviours. With respect to phenotypic plasticity i.e. heat hardening, I did not find any evidence of thermal tolerance plasticity during my experimental trials but few individuals did show increased thermal tolerance implying intraspecific variation. Additionally, the results from heat hardening experiments found no support for trade-off hypothesis. My study underscores the importance of habitat heterogeneity for species like spiny-tailed lizard which thrives in extreme temperatures. Furthermore, Lack of phenotypic plasticity in thermal tolerance increases it’s risks to overheating and dependency on behavioural thermoregulation.
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    Spatial and Temporal Overlap of Nilgai (Boselaphus tragocamelus) and Cattle (Bos taurus) and Its Implications for Parasite Burden and Prevalence
    (Wildlife Institute of India, Dehradun, 2025) Singh, Surya Pratap; Kawlni, Lallianpui; Kolipakam, Vishnupriya; Sadhu, Ayan
    Humans have depended on domesticated animals and plants since the origin of agriculture, and forests and grasslands have provided essential resources such as grazing and forest products. But there is greater overlap today between livestock and wildlife as a result of greater deforestation and growing human activity, and this has implications for the transmission of disease at these interfaces. In this dissertation, the impacts of spatial overlap, environmental variables, and animal behavior are investigated for their influence on patterns and drivers of gastrointestinal parasite load in nilgai (Boselaphus tragocamelus) and cattle, a commensal wild ungulate of the Indian peninsula. During December 2024 to March 2025, the study was conducted in the Darra enclosure of Mukundra Hill National Park. In addition to spatial information regarding animal locations with respect to villages, water points, and livestock distribution, field measurements were collected on parasitic burden, which was expressed as eggs per gram (EPG) in fecal samples. The research attempted to determine the impacts of spatial overlap among livestock and wildlife and proximity to these attributes on parasite intensity and prevalence. Statistical tests revealed no substantial relationship between the parasitic load of cattle and their proximity to villages or water points, contrary to preliminary hypotheses. All individuals sampled carried high EPG values consistently, revealing an overall parasite burden. Widespread parasite exposure regardless of spatial gradients due to common grazing, minimal pasture rotation, and homogenous environmental conditions are most likely the primary reasons for such a pattern. The research explored whether temporal and spatial coincidences with livestock, in this case cattle, can be channels of parasite transmission for nilgai. The findings indicate that the impact of spatial proximity can be overcome by aggregating at shared resources and chronic exposure to soiled environments and that it consistently yields high infection rates in domestic and wild ungulates. These results underscore the importance of considering environmental context, grazing management, and animal behavior when designing parasite control strategies. Instead of simply considering physical distance to villages or water sources, interventions taking into account pasture management and resource allocation may be more effective. The research presents valuable information for the prevention of disease, management of wildlife, and conservation of India's domestic and wild ungulates.
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    Status, habitat use and factors affecting breeding waterbirds of Changthang Wildlife Sanctuary, Ladakh (India).
    (Wildlife Institute of India, Dehradun, 2020) Mahar, Neeraj
    Tourism has evolved as an alternative livelihood for the local people and has reduced their direct dependencies on natural resources and perhaps indirectly contributed towards nature conservation. However, unregulated tourism activities have led to degradation of natural systems and increased the ecological vulnerabilities of local communities. Often, tourism and other developmental activities related disturbances collide with the peak season for several biological processes and affect the ability of natural system to revive and restore itself. In case of waterbirds these disturbance affect the breeding success. Other than anthropogenic activities, domestic dogs, apparently the most abundant carnivores in the world, pose a major threat to local wildlife. Recent studies have determined waterbirds as an important part of their diet. The existing literature clearly suggested that there was a huge information gap regarding Trans-Himalayan wetlands and their avifaunal characteristics. Previous studies were either site specific or species-specific, and thus, landscape level base line data was either scanty or unavailable. The Trans-Himalayan wetlands of India are increasingly under anthropogenic stress which is affecting their ecological structure and functions, especially the breeding birds. Blacknecked crane (BNC) is one of the flagship species of these wetlands. With the above background, I decided to study and understand their ecology and major threats faced by waterbirds and wetlands of Changthang Wildlife Sanctuary (CWLS). The objectives for this work were to (1) assess the population status and habitat use by waterbirds, (2)evaluate the factors affecting the breeding waterbirds, and (3) assess change in the wetland area.
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    Patterns of structural and functional attributes of alpine meadows of temporal scale in Tungnath, Western Himalaya
    (Wildlife Institute of India, Dehradun, 2023) Kumar, Rahul
    The present study was carried out to understand the temporal changes in structural (richness, diversity, of alpine communities, above and belowground biomass, net biomass accumulation/productivity, and carbon density) and functional attributes (Phenology of species recorded) of different alpine plant communities of alpine meadows. This research work has not only generated information on baseline ecological characteristics of species and communities but also provides valuable management implications. The study is summarized in the following paragraphs. The major objectives of the study are: 1. To study temporal changes in composition, structure, and functional attributes across various herbaceous communities, 2. To study the phenological patterns of dominant plant species across various communities in relation to abiotic parameters (rainfall/snowfall and temperature), 3. To assess the patterns of biomass production, carbon storage and sequestration in various communities and temporal dynamics of soil nutrients The study was carried out in Tungnath region of Western Himalaya which lies on outer fringe of Kedarnath Wildlife Sanctuary in the upper catchment of the river Mandakini, a major tributary of the Alaknanda, which finally join the river Ganga at Devprayag. Climate change particularly endangers organisms with fragmented habitat distribution, especially those with narrow ecological ranges, which may lead to extinction. Cold-adapted species are especially vulnerable in high alpine meadows due to rapid warming, potentially exceeding their adaptive capacity. The alpine zone covers 9 % of the total area in Greater Himalaya. In Uttarakhand, there are 5 protected areas encompassing alpine region namely Nandadevi National Park (NP), Valley of Flowers NP, Govind Pashu Vihar NP, and Wildlife Sanctuary (WS), Kedarnath WS and Askot WS of which except Nandadevi NP and Valley of Flowers NP, others are heavily exploited leading to habitat degradation. Exploitative practices such as unsustainable pastoralism, excessive extraction of medicinal plants, pilgrimage pressure, and poorly planned developmental projects are major challenges faced by alpine ecosystems in the Greater Himalaya. Therefore, it is crucial to understand species and community ecology to identify stress mechanisms and develop effective conservation strategies in Greater Himalaya. Numerous studies have shown correlations between temperature, precipitation, productivity, plant interactions, spatial patterns, and species richness in alpine ecosystems outside of the Himalayas. However, knowledge about the Himalayan alpine regions is limited due to their micro-topographic variations, altitudinal gradient, temperature range, and precipitation patterns, which make it challenging to isolate specific variables responsible for environmental-species relationships. These issues can lead to smaller population sizes, habitat degradation, and local extinctions, putting immense stress on alpine meadows. To address these challenges and conserve alpine meadows, it is essential to study sustainable land use practices adopted by local communities and develop conservation plans tailored to specific sites and species.
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    Role of top predators in shaping carnivore communities.
    (Wildlife Institute of India, Dehradun, 2021) Solanki, Riddhima; Qureshi, Qamar; Jhala, Y.V.
    The aim of the study was to explore sympatric carnivore in higher trophic interaction with lower trophic carnivore within the guild. The selection of site was based on this requirement. The core of well managed tiger reserve where impact of anthropogenic effect (encroachment, livestock, domestic dogs), if not prevented, were limited. The sampling design oriented for tiger initially was updated for other carnivore sampling. The small grid size (1x1) proved suitable for photo capturing smaller carnivores. In this study an attempt was made to winnow the carnivore guild according to body size. The limitation was carnivore community composition differed within the same central Indian landscape. In Bor, major representation was by Jungle cat and limited photo capture of other meso-carnivores. Similarly, honey badger was detected largely in NSTR followed by Melghat. A uniform and grid based camera trap cannot necessarily account for capture of all small carnivores due to habitat and terrain preferences. Although the single season occupancy analysis did not show significant relation with any habitat characteristics like terrain, human disturbance and forest cover but avoidance between trophics was observed at patch level. The composition of a patch is mostly not used to understand the occurrence of animals. In a protected area dominated by deciduous forest type presents substantially uniform landcover type.
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    Landscape-level assessment of select group of pollinators and factors influencing their diversity and distribution in Kullu Valley, Himachal Pradesh.
    (Wildlife Institute of India, Dehradun, 2024) Khan, Sushmita; Uniyal, V.P.; Ramesh, K.
    Change detection analysis using satellite data in a remote sensing platform is a crucial tool for understanding shifts in land use and land cover (LULC) over time, allowing for the identification of environmental and human-induced changes across various spatial and temporal scales. This method aids in assessing the impact of factors like urban expansion, agricultural practices, deforestation, and climate change on biodiversity and ecosystems. Climate change, particularly in vulnerable regions like the Himalayas, poses significant threats to ecosystem services and biodiversity. This study explores the impact of LULC and climate change on pollinator diversity and distributional patterns in the Kullu and Tirthan valleys of Himachal Pradesh. By compiling a comprehensive list of entomofauna pollinators across various orchards in different landscape configurations, the research aims to emphasize the need of conserving pollinator species in this ecologically sensitive region. Additionally, the study predicts potential shifts in pollinator distribution under future climate scenarios, providing valuable insights for conservation strategies. Through systematic analysis, the research contributes to a deeper understanding of pollinator communities and their interactions within the mountain horticultural belt of the Indian Himalayan Region. Ultimately, the findings aim to inform targeted conservation efforts to preserve the rich biodiversity of pollinators in this area. The research focuses on two major valleys within the Kullu district, each presenting contrasting landscapes and ecological contexts. The Kullu valley, a 76 kms long stretch situated along the Beas river, is characterized by diverse land use patterns and heightened anthropogenic activity, particularly in horticulture and tourism. In contrast, the Tirthan valley, nestled along the Tirthan river for a 45 kms long stretch, is designated as a conservation area with minimal disturbance and dense forest cover. The study meticulously investigated pollinator diversity dynamics in the Kullu and Tirthan valleys. The study conducted in the Kullu Valley aimed to analyze land use changes over time using Landsat satellite imagery from 2000 and 2022. High-quality images with minimal cloud cover were obtained for both years, ensuring accurate analysis With the aforesaid aim in focus, I have tried to address the following three objectives in my thesis: Objective 1: To assess the change in landscape composition of the study area over time.• Objective 2: To assess the effect of change in landscape configuration and horticultural practices on pollinator communities (diversity and abundance) and their services. • Objective 3: To model the distribution of major pollinators of economic importance belonging to different groups (Hymenoptera, Lepidoptera, Coleoptera, Diptera) in the study area.