Browsing by Author "Gupta, Sandeep Kumar"

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    Assessment of genetic variation in Sambar deer (Rusa unicolor)
    (wildlife Institute of India, 2014) Gupta, Sandeep Kumar; Hussain, S.A.
    This study is focused on the examination of intra and inter-species genetic variation among Indian sambar (R. u. unicolor) populations using mitochondrial DNA (mtDNA) and nuclear DNA markers. Sequence variation in a partial fragment of mtDNA control region was examined from the biological samples collected from Western Ghats, Deccan Peninsula, Semi-arid and Gangetic plains. It is also essential to know the phylogenetic variations (if any) among sambar population in India for identification of population(s) for proper conservation management. Therefore, the following objectives were set forth: (a) to examine the intra-species relationship among sambar populations across various biogeographic zones in India, (b) to study the molecular systematic of sambar in order to understand its phylogenetic structure and its relationships with other cervids; and (c) to examine the genetic diversity and gene flow pattern among sambar populations. The key research questions were (a) is there any variation in phylogenic position of sambar across biogeographic zones of India? (b) what is the precise phylogenic position of sambar with respect to other cervids? (c) does the population genetic structure of sambar differ across biogeographic zones of India? and (d) what is the status of gene flow in sambar across biogeographic zones? In this study, one ancient evolutionary significant unit (ESU) of sambar was identified from Western Ghats.
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    Spatio-temporal distribution, abundance and habitat use patterns of Gangetic river Dolphin (Platanista gangetica) in the lower Ganga river, Indian with respect to its conservation
    (Wildlife Institute of India, Dehradun, 2026) Das, Gaura Chandra; Gupta, Sandeep Kumar
    River dolphins are among the most evolutionarily distinct and endangered cetaceans worldwide, with the Gangetic river dolphin (Platanista gangetica) representing one of the last surviving obligate freshwater species. Historically widespread across the Ganga– Brahmaputra–Meghna river system, Gangetic river dolphin (hereafter, GD) has experienced pronounced range contraction, population fragmentation, and localized extirpations due to escalating anthropogenic pressures, including river regulation, habitat modification, intensive fisheries, and expanding human use of riverine resources. Despite its ecological role as an apex predator and indicator of river health, comprehensive and integrative assessments of its abundance, spatial distribution, habitat use, and conservation challenges across human dominated river stretches particularly in the lower Ganga River, have remained limited. This study addresses these gaps by generating robust ecological and socio-ecological evidence to inform conservation and adaptive management of GD in the lower Ganga River. The research integrates large-scale population assessment, habitat ecology, methodological evaluation of survey techniques, and human dimensions of conservation. Specifically, the objectives were to (i) assess seasonal patterns in dolphin abundance and distribution, (ii) derive reliable abundance estimates by explicitly accounting for imperfect detection using mark– recapture frameworks, (iii) identify key environmental drivers influencing spatio-temporal patterns of habitat use and occupancy, and (iv) evaluate the perceptions and attitudes of local fishing communities towards dolphin conservation and human–dolphin interactions. The study was conducted along a ~435 km stretch of the lower Ganga River, extending from the Ghaghara and Ganga river confluence (N 25 ° 45 ′ 10.49 ′′, E 84 ° 38 ′ 39.03′′) at the Uttar Pradesh and Bihar border to the Farakka Barrage (N 24 ° 48 ′ 22.16 ′′, E 87 ° 55 ′ 55.10′′) in West Bengal. This region encompasses a heterogeneous mosaic of fluvial habitats shaped by monsoonal hydrology, including braided and meandering channels, deep pools, sandbars, and major confluence zones formed by tributaries such as the Ghaghara, Gandak, Kosi, and Son rivers. These geomorphic features generate critical hydraulic refugia and productive habitats that support river dolphins and associated biodiversity. Despite its ecological significance, the stretch is subject to intense anthropogenic pressures, with the Vikramshila Gangetic Dolphin Sanctuary representing the only formally protected riverine segment within the study area. Boat-based visual surveys employing an independent double-observer design were conducted between 2018 and 2020 during pre- and post-monsoon seasons. The river was systematicallydivided into transects and 5 km Biodiversity Evaluation Units to standardize sampling. GD abundance was estimated using closed-population mark–recapture models, while seasonal variation was examined using non-parametric repeated-measures analyses. A total of 1,889 dolphin sightings were recorded, revealing strong spatial heterogeneity in encounter rates. Estimated abundance increased from 472 ± 73 individuals in pre monsoon, 2018 to 680 ± 73 individuals in post monsoon, 2020, with mean detection probability of approximately 0.69. Seasonal variation in dolphin counts across river segments was statistically significant (χ2 = 11.75, df = 4, p = 0.019), although pairwise seasonal differences were marginal. These findings highlight the conservation importance of specific river stretches and underscore the need for site-specific management and long-term monitoring. To address detection bias in visual surveys, a comparative assessment integrating boat based visual survey with aerial surveys using a tethered blimp was conducted. Aerial surveys consistently recorded higher dolphin numbers and larger group sizes, particularly in wide and turbid channels. Detection probabilities were substantially higher for aerial surveys (mean p = 0.81) compared to boat-based surveys (mean p = 0.61). Integrating both methods within a mark–recapture framework improved the accuracy and precision of abundance estimates, demonstrating the utility of aerial platforms for monitoring river dolphins in complex riverine environments.Habitat-use analyses revealed that dolphin encounter rates remained relatively stable across seasons; however, depth use exhibited significant seasonal variation. Manly’s selection ratios consistently indicated strong selection for deeper channels, particularly depths exceeding 10 m. Size-class distribution varied across channel types, with adults, sub-adults, and calves predominantly associated with wide single meandering and wide single straight channels. Single-season occupancy and N-mixture models revealed high site occupancy across the study stretch, with channel depth and meander complexity emerging as the strongest predictors of both occupancy and abundance. Channel width negatively influenced detection probability, emphasizing the need to account for habitat-driven detectability differences in population assessments. Recognizing the importance of human dimensions in river dolphin conservation, the study also assessed socio-economic conditions and conservation perceptions of fishing communities. Semi-structured interviews were conducted with 256 fishermen across 40 villages in Bihar, Jharkhand, and West Bengal. Overall, most respondents expressed positive (66.02%) or neutral (33.59%) perceptions towards dolphin conservation, with explicitly negative perceptions being rare (0.39%). However, CHAID analysis revealed that direct experience of dolphin entanglement in fishing gears was the strongest determinant of negative perception (χ2 = 93.62, p < 0.001). Education level had a secondary but non-significant influence, while livelihood dependence and fishing experience showed no significant effects. These findings indicate that attitudes towards dolphin conservation are primarily shaped by direct livelihood-related conflicts rather than socio-demographic factors alone. Further, this study provides an integrated understanding of the population status, habitat ecology, detection challenges, and socio-economic dimensions of GD conservation in the lower Ganga River. The results emphasize the critical importance of deep, meandering channel habitats, the need for improved survey methodologies, and the central role of conflict mitigation in fostering coexistence between dolphins and fishing communities. The findings offer a strong scientific foundation for prioritizing conservation actions, informing adaptive river management, and integrating ecological and social considerations in conservation planning within increasingly fragmented riverscape of the Lower Ganga basin.