Theses and Dissertations
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Item Foraging Guild Structure and Niche Characteristics of Waterbirds in Pong Wetland, Himachal Pradesh(Wildlife Institute of India, Dehradun, 2025) Abhishek; Talukdar, Gautam; Gopi, G.V.; Kaur, AmarjeetWetlands are one of the important habitats for waterbirds, yet the mechanism of niche segregation among the waterbird communities is understudied. This study focused on the foraging guild structure and niche characteristics of waterbirds in Pong wetland during the wintering season. The study takes into account foraging habitat (water depth, secchi depth and vegetation type) and foraging technique used by the waterbird species to understand resource partition and coexistence. The study was carried out from December 2024 to March 2025 using the point count method in two different sites of the Pong wetland i.e., Meenu khad and Gaj khad each having five replicates. The total sampling effort was 56 days with 26 days in Meenu khad and 30 days in Gaj khad. The species richness analysis of both the sites revealed Meenu khad to be more species rich than Gaj khad likely due to variation in water depth in the region, resulting in different habitat conditions. The monthly abundance of waterbirds in Pong wetland was found to be at its peak in the month of January. Generalist species such as the Eurasian Coot and Tufted Duck occupied the broadest habitat and combined niche breadth than that of specialists such as the River Tern. Furthermore, in terms of extensive foraging strategy, species such as the Northern Shoveler and Intermediate Egret occupied broader niche breadth, demonstrating behavioral flexibility in resource acquisition. The clustering of waterbird communities resulted in four functional guilds that are responsible for reducing competition and allowing species coexistence. It was found that the intraguild overlap was significantly higher than the interguild overlap (F = 54.34, p < 0.001). The null models further showed the mechanism that could be responsible for structuring the communities. It resulted in higher observed niche overlap than expected, signifying that community structure of waterbirds is largely influenced by morphological variations leading to different foraging habits, variable abundance of waterbird species and presence of abundant resources at Pong Dam. This study is the first in providing deeper understanding on seasonal waterbird abundance, niche requirements and community structure at Pong Lake. This study serves as a baseline to continue future studies in the region and assess the impacts of changing land use practices as well as changing climate on species occurrence and abundance and community structure. Furthermore, the study also showed the region to be an important staging ground for many migratory species, therefore, focusing on targeted habitat management will be crucial to support the diversity of waterbird species.are one of the important habitats for waterbirds, yet the mechanism of niche segregation among the waterbird communities is understudied. This study focused on the foraging guild structure and niche characteristics of waterbirds in Pong wetland during the wintering season. The study takes into account foraging habitat (water depth, secchi depth and vegetation type) and foraging technique used by the waterbird species to understand resource partition and coexistence. The study was carried out from December 2024 to March 2025 using the point count method in two different sites of the Pong wetland i.e., Meenu khad and Gaj khad each having five replicates. The total sampling effort was 56 days with 26 days in Meenu khad and 30 days in Gaj khad. The species richness analysis of both the sites revealed Meenu khad to be more species rich than Gaj khad likely due to variation in water depth in the region, resulting in different habitat conditions. The monthly abundance of waterbirds in Pong wetland was found to be at its peak in the month of January. Generalist species such as the Eurasian Coot and Tufted Duck occupied the broadest habitat and combined niche breadth than that of specialists such as the River Tern. Furthermore, in terms of extensive foraging strategy, species such as the Northern Shoveler and Intermediate Egret occupied broader niche breadth, demonstrating behavioral flexibility in resource acquisition. The clustering of waterbird communities resulted in four functional guilds that are responsible for reducing competition and allowing species coexistence. It was found that the intraguild overlap was significantly higher than the interguild overlap (F = 54.34, p < 0.001). The null models further showed the mechanism that could be responsible for structuring the communities. It resulted in higher observed niche overlap than expected, signifying that community structure of waterbirds is largely influenced by morphological variations leading to different foraging habits, variable abundance of waterbird species and presence of abundant resources at Pong Dam. This study is the first in providing deeper understanding on seasonal waterbird abundance, niche requirements and community structure at Pong Lake. This study serves as a baseline to continue future studies in the region and assess the impacts of changing land use practices as well as changing climate on species occurrence and abundance and community structure. Furthermore, the study also showed the region to be an important staging ground for many migratory species, therefore, focusing on targeted habitat management will be crucial to support the diversity of waterbird species.Item Assessing Ghost crab distribution, abundance and habitat use along the Coromandel Coast, Tamil Nadu(Wildlife Institute of India, Dehradun, 2025) Keerthi V; Gopi, G.V.Sandy beach ecosystems around the world are facing numerous threats and tremendous pressure due to ever increasing human population. One such threat, relevant to the Indian coastline, is the large scale plantations of shelterbelts of the exotic pine, Casuarina equisetifolia, which alters beach geomorphology. The effects of such plantations on permanent shore-dwelling organisms are poorly studied. Hence Ocypode crabs, the most conspicuous macro-invertebrate on sandy beaches, has been used as a model taxon to study the effects of different kinds of inland vegetation (Casuarina plantations, Mangrove plantations, native dune vegetation) on beach geomorphology and consequently, shore dwelling ghost crabs. The present study aims to - (1) Assess the density, distribution and demography of ghost crabs across treatments (2) Understand variations in habitat use and burrow architecture across treatments (3) Understand the effects of inland vegetation on beach geomorphology 2. A total of 24 transects, temporally replicated thrice each month between January 2025 - April 2025, were walked to estimate densities of ghost crabs using burrow counts as a proxy. 87 burrows across the treatments were cast using a mixture of Plaster of Paris and water and traits such as depth, diameter, shape and branching patterns were studied. Coast characteristics like slope, compactness, beach width, moisture and temperature were recorded at each study site. 3. Mean burrow densities and across shore distribution of Ocypode ceratophthalmus differed across the treatment types, with lowest densities in beaches adjacent to Casuarina plantations. This however wasn't statistically significant. The burrow structures also differed in complexity across treatments with the major drivers for this 7 difference being the size of the crab and the type of inland vegetation. Environmental variables were not found to have significant effects on burrow architecture. 4. The results indicate that the type of inland vegetation affects the population of ghost crabs through changes in beach geomorphology. Ghost crabs were also found to modify the structure of their burrows with changes in the habitat quality and environmental conditions, which gives insights into their adaptive capacities. The study, thus raises questions on the effects of certain management interventions, like the planting of shelterbelts on habitat quality and on the ecology of the species dwelling in the said habitats.Item Estimating Abundance, Habitat Use, and Acoustic Characteristics of Irrawaddy Dolphins (Orcaella brevirostris) in Chilika Lagoon(Wildlife Institute of India, Dehradun, 2025) Sakshi; Kolipakam, Vishnupriya; Gopi, G.V.This study provides a comprehensive assessment of the Endangered Irrawaddy dolphin (Orcaella brevirostris) in Chilika Lagoon, India, through an integrated approach combining visual and acoustic surveys, environmental modelling, and prey availability analysis. Visual line-transect surveys and passive acoustic monitoring (using FPODs) were used to estimate dolphin abundance and explore patterns of habitat use. Dive-time observations revealed that calves and non-calves differ in their diving behavior, with non-calves exhibiting longer and more variable dive durations. Mark-recapture analysis produced corrected abundance estimates ranging from 24 to 32 individuals, with variation influenced by observer mismatches and brief surfacing events. To assess prey availability, catch per unit effort (CPUE) surveys were conducted at 22 sites in collaboration with local fishers. The highest CPUE values were recorded in the high salinity area (Outer channel) and low salinity area (Northern sector), indicating these areas may offer better foraging opportunities. Prey community sampling across 11 sites revealed spatial differences in species richness and evenness, with some locations dominated by a few taxa and others exhibiting high diversity. Richness estimators suggested that the true species count exceeds what was observed, indicating under-sampling in certain areas. Environmental modelling using a negative binomial generalized linear model showed that salinity had a significant negative effect on dolphin acoustic detections, while dissolved oxygen and depth were positively associated but not statistically significant. The frequency ranged from 20 kHz to 200kHz with a median frequency of 98kHz. The interclick interval ranged from 850 millisecond to 1010865 milliseconds with a median of 23605 millisecond. The histogram for ICI displayed a positively skewed distribution, consistent with irregular click trains interspersed with longer pauses. The findings highlight the importance of salinity and prey availability in shaping dolphin distribution in Chilika Lagoon. The results support targeted conservation actions such as regulating freshwater inflow, protecting productive foraging zones, and expanding acoustic monitoring efforts to improve long-term management of this vulnerable population.Item Genetic assessment of the Non-descript pig breeds across selected regions of Uttarakhand(Wildlife Institute of India, Dehradun, 2023) Sahoo, Khushboo; Gupta, S.K.; Gopi, G.V.India, which has ancient history of pig rearing, is home to several indigenous pig breeds that reflect the adaptation of Sus scrofa to different environmental and cultural conditions. However, only 13 of these breeds are currently recognized and documented by the National Bureau of Animal Genetic Resources. The present research was undertaken to identify the spatial distribution, socio-economic status, pig husbandry methods of pig rearers, and the impact of Exotic pig breed on the indigenous breed and ecology of the region. As molecular characterization is a valuable tool that provides insights into the evolutionary history and genetic diversity of the current pig breed raise in a region. Hence by incorporating molecular techniques in understanding of the domestic pig breed and their interactions with ecosystems, promote more precise and science-based management that contributes to biodiversity conservation and sustainable husbandry practices. The present study will also aim to evaluate the maternal lineage, genetic diversity and population structure of the domestic pig breeds at the regional scale, using microsatellite markers and mitochondrial DNA sequences. The survey and sampling was done in the planar (Dehradun, Haridwar and Nainital) districts of Uttarakhand, a mountainous state of India that lies in the foothills of Himalayas, where rapid urbanisation and continuous migration make us reconsider the necessity of an organise promotion of the piggery sector due to its multiple ecological implications.Item Study on distribution and relative abundance of large mammals and impact of human disturbance in and arond Mehao Wildlife Sanctuary, Arunachal Pradesh(Wildlife Institute of India, Dehradun, 2023) Ahmed, Arif; Gopi, G.V.The current study was started to gather baseline data on a few ecological factors (Diversity, distribution, relative abundance, Activity pattern and habitat preference) of selected large animals in Mehao WS. Northeast India. The study period was November 2017 to 2020. The objectives of the study are 1. To estimate the relative abundance and occupancy of selected large mammals in and around Mehao wildlife sanctuary. 2. To develop Habitat suitability model for selected large mammals in and around Mehao WS 3. To analyse the land use/land cover change pattern and to identify the main driving factors.Item Foraging ecology of Great-Slaty Woodpecker in and around Pawalgarh Conservation reserve in Western Himalaya(Wildlife Institute of India, Dehradun, 2024) Kaur, Sarabjeet; Gopi, G.V.; Uniyal, V.P.The Great Slaty Woodpecker (Mulleripicus pulverulentus, Temminck 1826) is an old-world woodpecker that prefers mature and old-growth dipterocarp forests (including Shorea robusta, Sal) across its known distribution range. The study reveals population demography, the social system and foraging behavior from logged forest and infer the distribution and home range of the Great Slaty Woodpecker, a cooperative breeding bird species, in and around the Pawalgarh Conservation Reserve in the western Himalaya of Uttarakhand state. This study presents the first census conducted for the Great Slaty Woodpecker, providing an ecological baseline for the species population estimation from its known distribution range. I inferred the home range size of each group based on 161 independent sightings of 11 family groups. These sightings represent behaviors such as foraging, nesting, roosting, vocalizations, and territory defenseItem Effect of land use change on the habitat and abundance of Grizzled giant squirrel in and around Srivilliputhur-Meghamalai Tiger reserve, Srivilliputhur Division, Tamil Nadu(Wildlife Institute of India, Dehradun, 2024) Bevoor, Shilpa; Gopi, G.V.; Kher, Varun; Goyal, S.P.Human activities, especially energy extraction and food production, have drastically altered the global environment, impacting many wild species. Since 1990, around 420 million hectares of forests have been lost mainly due to agricultural conversion, significantly affecting biodiversity. In biodiversity hotspots like India's Western Ghats, agricultural expansion, monoculture plantations (tea, coffee, rubber), and non-timber forest product harvesting have fragmented protected areas, altered plant communities, disrupted nutrient cycles, and reduced carbon sequestration. While monoculture plantations reduce biodiversity, they can still provide habitats for some threatened species. Wildlife such as nilgai, blackbuck, elephants, and giant squirrels in India have adapted to these altered landscapes for food, water, and shelter, demonstrating resilience amidst habitat changes. This study focuses on the impact of converting barren lands into mango and coconut plantations around the Srivilliputhur-Megamalai Tiger Reserve in southern India on the grizzled giant squirrel population and habitat. Over the past three decades, these changes have enhanced connectivity between natural forests and agricultural areas, offering energy-rich fruits that attract wildlife, including GGS. This shift has altered ecological dynamics, making wildlife more reliant on cultivated foods and affecting their movement patterns. Density estimates reveal higher concentrations of GGS and nesting sites (dreys) in plantations compared to protected areas, with mixed plantations showing the highest densities due to the availability of nesting sites and year-round fruiting trees. Seasonal variations in GGS distribution highlight preferences for specific tree species based on fruit availability and habitat characteristics. The study also examines drey site preferences, noting GGS preference for mango trees in plantations over coconut trees due to structural attributes that provide better support and protection. These findings underscore the species' adaptation to plantation environments while emphasizing the critical role of specific habitat features for nesting and overall habitat suitability. Local farmers report conflicts with GGS due to crop damage, particularly affecting coconut, mango, tamarind, and other fruit-bearing trees. Perceived economic losses from GGS feeding habits often exceed actual damage levels, emphasizing the need for accurate assessment and targeted mitigation strategies to reduce conflict. Conservation implications stress the importance of maintaining critical habitats within protected areas, establishing buffer zones between plantations and natural forests, and promoting biodiversity-friendly practices in monoculture plantations. Community-based conservation efforts and adaptive management strategies are essential for mitigating human-wildlife conflicts and ensuring the sustainable coexistence of GGS and agricultural livelihoods in this biodiversity hotspotItem Golden Langur Distribution, Habitat Selection and Corridor – Connectivity: Assessing Patterns and Addressing Threats(Wildlife Institute of India, Dehradun, 2024) Basumatary, Rishi; Nath, Anukul; Gopi, G.V.; Chetry, DilipThe Golden Langur (Trachypithecus geei), is an endangered colobine primate, confined to fragmented forest patches in western Assam, India, and south-central Bhutan. The golden langur has experienced severe habitat loss and fragmentation due to ethnolinguistic and religious conflicts between the late 1980s and late 1990s, followed by developmental activities in western Assam. The primary threat faced by the golden langur in India are the rapid reduction of its natural environment and the fragmentation of its habitat. Factors such as a limited population size, the breakdown of meta-population dynamics, and unique traits of a species often make a population in a fragment more likely to experience local extinction. Due to the significant decline in the range of Golden langur in both Bhutan and India, as well as the ongoing destruction of their habitat in India, it is imperative to safeguard even the smallest local populations. The populations residing in these fragmented Reserved Forests and Proposed Reserved Forests are effectively confined, separated from the primary breeding population, and susceptible to demographic and genetic influences. The objective of this study is to understand the current distribution, suitable habitat, and connectivity of corridors for the severely fragmented southern population of golden langur in India. Additionally, the study aims to examine the specific habitat preferences and demographic patterns of langur groups, as well as evaluate the threats that this fragmented population faces. The study was carried out in nine fragmented forest patches that includes Wildlife Sanctuary (WLS), Community managed RF (CMRF) Reserved Forest (RFs), and Private Rubber Plantations and Adjoining Forests (PRP_AF). In the present study, a total of 123 trails, ranging from 0.4 km to 1.6 km, were walked, covering a total distance of 118.72 kilometers. During these surveys, a total 51 troops (including 8 multi-male multi-female troops and 5 all-male groups), consisting of 499 individuals were encountered. The mean group size and age-sex ratio between different protected regimes that include wildlife sanctuary (WLS), community managed RF (CMRF), reserved forest (RF) and private rubber plantation and adjoining forests (PRP_AF) were compared. The overall mean group size of the langur was 9.78 (± 0.69 SE). Of the total 499 individuals, 13.22 % comprised of adult males, 41.88 % adult females, 16.83 % sub-adults, 10.02 % was juveniles and 18.03 % was infant. The average age-sex ratio of adult males to adult females was 0.287 (± 0.04 SE), juveniles to adult females was 0.224 (± 0.02 SE) and infants to adult females was 0.407 (± 0.04 SE). The infant to female ratio was found higher in wildlife sanctuary as compared to other reserved forests in the study area. The current study revealed that approximately 883 km² of the area is highly suitable for the endangered golden langur. Percent forest cover was found to be the most important variable in determining the probability of occurrence of golden langur in India. The corridor connectivity analysis showed high conductance for corridors namely Bamungaon and Khoragaon RF. Similarly, the connectivity is permeable between Kakoijana and Bamungaon. Other corridors identified in the study are Bhumeshwar Hill, Nakati RF and Kakoijana RF. On the other hand, there is high conductance among corridors of Chakrashila WLS and Nadangiri RF. Additionally, fine scale habitat selection study showed that tree species diversity, canopy cover and food plant density are the key in determining the occurrence of golden langur. In the last six years, a total of 56 mortality and injury incidents were reported from the study area which include 45 deaths and 11 injuries. Electrocution accounted for 29 cases, especially near forest edges, while 21 road accidents occurred mainly on national and state highways, as these roads are broader and have higher traffic volumes compared to village and town roads. Most accidents happened in the corridors between Chakrashila WLS-Nadangiri RF and Kakoijona RF-Bamungaon RF. Specific measures need to be taken to minimize electrocutions and road accidents of golden langur in the region. Mitigation measures like insulating electric lines and road safety protocols such artificial canopy bridges (ACB) and metal animal overpasses (MAOP) are essential for safe and easy movement along these corridors for the golden langur's survival in fragmented habitatsItem 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.