Theses and Dissertations
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Item Habitat Utilisation of Asian Water Monitor (Varanus salvator) in and Around Bhitarkanika National Park, Odisha(Wildlife Institute of India, Dehradun, 2025) Rayen, W. Michael Isaac V.; Pandav, Bivash; Das, AbhijitThe water monitor lizard Varanus salvator is the largest of all lizards in India, and its distribution is restricted to certain pockets of the northeast, eastern coast and Andaman and Nicobar Islands. Despite being the largest lizard, only limited studies have been done on this species, especially on the movement pattern and home range. This study focuses on the space use pattern of Varanus salvator in the mangrove habitats of Bhitarkanika National Park, Odisha. In total, five individuals were radio-tagged with VHF transmitters in the form of a backpack. All the tagged individuals were located twice in a day, and the location(coordinates), activity and other habitat variables were recorded. The data collected were analysed for their movement pattern, activity range and overlap between individuals and the human-dominated landscape was estimated using KDE. Along with the space use environmental variables (Ambient temperature, Relative humidity, vegetation species, canopy openness, etc) were analysed individually with behaviour to the relation between them using Fisher’s test. The results from this study add more information about its activity range, movement pattern and behavioural aspects in the mangrove landscape of India, which can be useful in the rescue, rehabilitation and management of the species.Item Tigers in a multi-use forest: Prey, diet and conflict(Wildlife Institute of India, Dehradun, 2025) Chauhan, Aayush; Pandav, Bivash; Habib, BilalThis study provides a comprehensive assessment of tiger prey, dietary dynamics, and human-wildlife interactions in the Ramnagar Forest Division, a critical area outside protected areas in the Western Terai Arc. Despite a notable increase in tiger numbers—from 39 adults in 2015 to 67 in 2022—density surface modeling revealed persistently low populations of key wild prey species such as chital and sambar, primarily due to habitat degradation from historical timber-focused management. Diet analysis of genetically confirmed tiger scats demonstrated a strong reliance on large-bodied prey, with sambar and livestock comprising a significant portion of tiger biomass intake, reflecting both prey scarcity and ecological stress. The detection of plastic in both sambar and tiger digestive tracts further highlights the emerging threat of environmental pollution in multi-use forests. Human-tiger conflict remains acute, with 353 livestock depredation events and 28 attacks on people recorded over recent years, concentrated near settlements where prey and livestock overlap are highest. These findings underscore the urgent need for integrated conservation strategies that prioritize habitat restoration—such as grassland recovery—community-based conflict mitigation, improved waste management, and a shift in forest policy from timber production to biodiversity and coexistence. Only through such landscape-level, participatory approaches can the long-term viability of tigers and their prey be secured in shared, human-dominated areas like Ramnagar.Item Understanding aspects of demography and resource partitioning mechanisms of large felids among with abundance and spatial distribution of prey in Similipal Tiger Reserve, Odisha(Wildlife Institute of India, Dehradun, 2024) Rathore, Harshvardhan Singh; Pandav, Bivash; Jhala, Y.V.This study investigates the crucial aspect of coexistence for large predators like tigers and leopards sharing the same landscape and delves into the population dynamics of these animals by identifying the mechanisms of resource partitioning. By acting as a window into the inner workings of the ecosystem, the study reveals how tiger and leopard populations function alongside each other. Identifying the factors that influence their ability to share the resources successfully is vital for developing more effective conservation strategies. This knowledge ultimately contributes to ensuring the long-term survival of both tigers and leopards in this landscape. A precise assessment of several demographic parameters is necessary to make informed management decisions for their conservation within this unique habitat. These parameters include population density, sex structure, recruitment, and survival rates. With this background, the study comes with the following objectives. (1) To assess the abundance and spatial distribution of prey in STR.(2) To assess the various demographic parameters of large felids (tiger and leopard) in STR. (3) To determine the mechanisms of resource partitioning of the tiger and the leopard in STR. Similipal Tiger Reserve is located in the Mayurbhanj district of Odisha, between86˚06' and 86˚36' East longitude and 21˚31' and 22˚02' North latitude. The study was carried out over three years (2019–2021) across eight ranges in the core area of STR: Chahala, Nawana North, Nawana South, and Pithabata South Wildlife in the northern core, and UBK, Jenabil, Bhanjabasa, and National Park in the southern core.Item Subsidized Mammals: Understanding the mammalian interactions with garbage sites around Western- Rajaji Tiger Reserve, Uttarakhand(Wildlife Institute of India, Dehradun, 2024) Nagarale, Shashank; Habib, Bilal; Shrotriya, Shivam; Pandav, BivashAnthropogenic food subsidies in the form of garbage dumps are widespread across the globe. When such sites are found around protected areas/wildlife habitats, wildlife is observed to exploit these subsidies as food resources. Foraging on such human-derived foods may have a negative or positive impact on individual to community/ecosystem levels. It becomes important to know the species associated with garbage dumps when found around protected areas and understand the interactions happening at the garbage dumps. This study was conducted aiming to know the animals at risk and also increase our understanding of these novel setups. I deployed 13 IR camera traps at total 10 garbage sites resulting in a cumulative effort of 437 trap nights at the garbage site. The camera trap data was processed using Megadetector & SpSeg packages in python. This data was used to get the Relative Abundance Index with respect to 437 trap nights. Sambar (RAI= 8.35) was the species with the highest visitations at the garbage site, followed by Indian crested porcupine (RAI= 2.70) and spotted deer (RAI= 2.15). Synanthropes like rhesus macaque (RAI= 1.78 ) and wild pig (RAI= 1.67) were the most visitors following spotted deer. I hypothesised that synanthropic species will have higher visitations because of distribution outside protected areas, followed by omnivores from the forest area as compared to herbivores and carnivores from the forest areas because of their ability to exploit larger variety of food resources. The data from this study rejected this hypothesis as forest dwelling species like sambar and Indian crested porcupine visited these sites more as compared to other synanthropes. Lesser visitations by omnivores like golden jackal, small indian civet, small indian mongoose; carnivore like common leopard along with scavenger striped hyena was a result of the less percentage of poultry waste (0.33% at only one site) in the garbage sites. I collected data on variables such as distance of the garbage site from the protected area, human infrastructure and waterbody, also quantified the size of the garbage site in terms of perimeter, NDVI difference between the protected area and garbage site as a surrogate of vegetation cover, relative abundance of each species in the adjoining protected area and calculated the composite RAI values of human, dogs/cats and livestock as a disturbance measure . I quantified the garbage in broader categories using a 1 m2 quadrat which was divided into smaller sets of 25x25 cm2. A total of 39 plots were laid for all the garbage site. The categories quantified were food wrappers & food disposables, food materials, religious offerings, agriculture discards, dung plates, sanitary waste, construction waste, carcass & poultry waste, pharmaceutical waste, cloths and plastic and others. The relation between relative abundances within protected area and visitations at the garbage site was assessed using Spearman correlation test along with Wilcoxon test p-values. With the available dataset I used ANOSIM using ‘vegan’ package in R program v4.1.2 to investigate the effect by considering the dissimilarity of the communities between sites based on the RAI values of the species for each garbage site. Relative abundance from protected area was not related to visitation of the species at the garbage site. Out of the selected variables, the ANOSIM values suggested the effect of ‘distance between garbage site and protected area’ on forest species and synanthropes. The effect of the ‘size of garbage site’ on the species could not be tested as there was not much variation in the sizes of the garbage sites. Human, dogs/cats and livestock presence affected the forest species, suggesting their sensitivity towards disturbances, while synanthropes were found to have affinity with the NDVI difference between protected area and garbage sites (vegetation cover at the garbage site) and the ‘percentage of food materials available in the garbage site’. To understand the co-occurrences at the garbage site, I modified the probabilistic models for co-occurrences (Veech, 2013) to get pair-wise associations at the temporal scale of one hour. A total 13 mammals avoided co-occurring with humans (and vehicle) while nine with livestock and dogs. Co-occurrences were found to be there between sambar and Indian crested porcupine at two out of three religious sites and at a household site, suggesting high tolerance levels to each other’s presence at the garbage site to exploit the resources. One of the sites was visited by barking deer with spotted deer group/herd. This association by solitary living barking deer can be for foraging effectively by reducing vigilance efforts in a group.Item Assessing the distribution and density of the Fishing Cat in Bhitarkanika mangroves of eastern India by(Wildlife Institute of India, Dehradun, 2024) Ashik, C.S.; Mukherjee, Shomita; Gopi, G.V.; Pandav, BivashIdentifying the areas of occurrence, population, and the factors affecting the species distribution is critical in conservation and management. The Fishing Cat (Prionailurus viverrinus), a smaller feline native to South and Southeast Asia, is globally vulnerable and adapted to wetland habitats, with a diet primarily consisting of fish. This makes Bhitarkanika, a mangrove ecosystem, an ideal habitat for the Fishing Cat. This study was conducted to estimate the species density, determine the factors affecting its distribution, and assess the effect of lunar illumination and tidal fluctuation on Fishing Cat activity. Despite known occurrences of Fishing Cats in this area, there has been no proper assessment of their population or other ecological studies. Camera traps were deployed in 109 grids, each covering 1km², across a total of 145 km², for 2878 trap nights. Camera trap locations are unbaited, with two cameras used to capture both flanks. Spatially explicit capture-recapture (SECR) was used to estimate the density, resulting in 0.6 ± 0.1 individuals per km². The abundance was also calculated, with an estimate of 99 ± 16 individuals. These density estimates from this study are close to recent high-density estimates for the species. The canopy cover, the width of the creek, canopy cover and the distance to the aquaculture farms significantly influenced the Fishing Cat habitat use, indicating the need for the conservation of natural mangrove habitats and regulation of aquafarms present near the forest. In contrast, the presence of Saltwater Crocodile showed a negative effect on the distribution of Fishing Cats. The Fishing Cats were more active during the brighter nights of the moon phase (μ= 266.783, r= 0.051, p< 0.01) due to better visual detection. The activity was influenced both by the tidal fluctuations in terms of food resources from waterbodies and it is further enhanced by the lunar illumination during the night. Pairwise non-parametric tests showed that the probability distributions of Fishing Cat activity under lunar illumination and tide fluctuation (D= 0.125, p-value = 0.9885 and D= 0.125, p-value= 0.9899) were similar, indicating minimal differences between each probability distribution. This study underscores the importance of protecting the mangrove habitat and controlling aquaculture expansion to ensure Fishing Cat survival in the Bhitarkanika National Park.Item Spatial Dynamics and Drivers of Nearshore Aggregations in Olive ridley Sea Turtles along the Gahirmatha Coast by(Wildlife Institute of India, Dehradun, 2024) Sarkar, Arnab Dey; Prabakaran, Nehru; Kumar, R.S.; Pandav, BivashOlive ridley sea turtles (Lepidochelys olivacea) exhibit a well-documented phenomenon known as nearshore aggregation during their breeding season. These aggregations, comprising large numbers of turtles in shallow coastal waters, are a common feature observed along most of the mass nesting beaches. The ecological benefits of such aggregations are multifaceted, potentially including enhanced predator avoidance and increased opportunities for mate encounter. The importance of studying these nearshore aggregations stems from their vulnerability during this period. Olive ridley turtles within these aggregations are susceptible to various threats, including bycatch mortality from fishing gear. Understanding the spatial and temporal dynamics of these aggregations is crucial for developing effective conservation strategies. The Gahirmatha nesting site presents a unique case due to the influence of the Brahmani-Baitarani River system. The substantial freshwater inflow and sediment discharge from this river system have resulted in a vast area of shallow seabed compared to other nesting grounds. This distinct ecological setting necessitates a dedicated investigation into the dynamics and influencing factors of nearshore aggregations specific to Gahirmatha. The study examined the distribution and density of olive ridley sea turtles near Gahirmatha, India, a critical nesting site, with a particular focus on how environmental factors influence the location of these nearshore aggregations. Surveys were conducted throughout the breeding season, recording turtle sightings and environmental data. The findings reveal that olive ridley turtles are not distributed randomly in the nearshore waters. Instead, they form concentrated aggregations in shallow depths (less than 5 km offshore and 5-15 meters deep) before nesting. The location and density of these aggregations were not static but shifted throughout the breeding season. During the pre-nesting season, turtles were more dispersed across a wider area. As the season progressed and nesting approached, the aggregation grew denser and shifted closer to the nesting beach. The study also identified distance from the coastline and the nesting beach as the key factors influencing the distribution of these nearshore aggregations. Additionally, the unique shallow seabed near Gahirmatha, created by the discharge from the Brahmani-Baitarani River, might influence the preferred depth range of turtles compared to other nesting sites. Understanding these dynamic aggregation patterns is crucial for effective conservation efforts. Protecting these areas is essential for the well-being of this globally significant olive ridley population. However, it's important to acknowledge that the exact locations of these aggregations can vary between years. This year's lower nesting numbers suggest fewer turtles arrived in the nearshore waters, potentially impacting the size and distribution of the observed aggregations. This study emphasizes the need for long-term studies to gain a more comprehensive understanding of these variations and the factors influencing them. The study suggests a targeted approach of focusing on areas with high turtle usage. By implementing stricter patrolling measures within these zones, the forest department can significantly reduce threats like bycatch mortality from fishing activities. This targeted approach would be more effective in safeguarding the turtles compared to focusing on reducing illegal fishing in the entire sanctuary, considering the limited resources available.Item Nest site selection in Pallas’s Fish-eagle and nesting behaviour in the Rajaji-Corbett landscape(Wildlife Institute of India, Dehradun, 2024) Tangaria, Abhishek; Jha, Ashish; Pandav, Bivash; Kumar, R.S.This study investigates the nest site selection and nesting behavior of Pallas's Fish-eagle (PFE) across the sub-Himalayan tract in India, addressing a significant knowledge gap in the species' natural history. PFE, classified as Endangered globally and of high conservation concern nationally, exhibits unique nesting preferences and ecological requirements. Prior research, including studies from Bhutan and Bangladesh, has highlighted the species' preference for unobstructed nest trees and proximity to water sources and human settlements. However, comprehensive data from India remains limited. The study aims to explore factors influencing PFE's nest site selection, such as habitat quality, microclimate, food availability, and protection from predators and human disturbance. Additionally, it seeks to document the species' reproductive behavior, including hatchling development, parental duties, and nest predation pressures. Surveys covered segments of the Ganga, Kohlu, Kho, Palain, Mandal, Asan Barrage, Dakpatthar Barrage, and Ramganga, recording data on sightings and nest characteristics. A total of twelve nests were found, with only one destroyed by a storm. The majority of nests were built on Bombax ceiba and Shorea robusta trees, with an average height of 29.9m and GBH of 473cm. Behavioral observations were conducted at three accessible nests, monitoring parental presence, predator interactions, and nest guarding behavior. Spatial analysis in ArcGIS Pro considered various land cover types and environmental factors, finding that barren land and rangeland significantly influenced nest site selection. Euclidean distances to different land cover types and elevation were also key factors. Statistical analyses using R revealed correlations between tree height and nest height, and generalized linear models highlighted the impact of land cover and environmental variables on nest presence. Nest trees were typically tall and robust, with Bombax ceiba and Shorea robusta being the most commonly used species. These trees provided unobstructed branches and greater accessibility. The study also highlighted the importance of open land around the nest tree, aiding in vigilance and territory defense. At a macro scale, the presence of barren land and flooded regions positively influenced nest site selection, while slope and distance from rangeland showed negative correlations. Behavioral observations at three nests revealed high predation pressure, particularly from crows, and kites. The presence of human settlements increased predation incidents, affecting parental investment in nest defense.Item Abundance and social organization of male Asian elephants (Elephas maximus) in Rajaji Tiger Reserve(Wildlife Institute of India, Dehradun, 2024) Madhusudanan, Abhimanyu; Pandav, Bivash; Lakshminarayan, N.; Mondol, Samrat1. Asian Elephants are complex, social, and polygynous mammals living in fission-fusion societies. Male elephants are known to alternate between leading solitary lives, in all-male groups or associating with mixed-sex herds. All-male groups allow younger males to learn from older males, test strengths and spar with their peers. While much work has been done on female Asian elephant societies, studies focused on male association patterns are limited, but gaining importance in the light of human-elephant conflicts. In this study, I estimated the abundance of adult male elephants in a stretch of forest spanning over 40 km along the east bank of the river Ganga in Uttarakhand using a polygon search-based spatially explicit capture recapture (SECR) framework 2. I invested a survey effort of ~3014 km to estimate the abundance of the adult male segment of the population using a capture-recapture framework. Using a combination of morphological features, I identified 34 adult males from 124 elephant sightings. Association patterns of the male elephants, following behavioural sampling approaches were also recorded during the surveys. 3. Adult male elephant density was 0.05 (SE=0.01)/km2, and a derived abundance of 40 (SE=1.4) for the 475 km2 study area. This demonstrates that polygon search-based SECR is an effective approach in estimating elephant abundance.