Browsing by Author "Rajvanshi, Asha"

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Assessment of the existing National Highway – 7 and its proposed widening on habitat use and movement of wild animals in Pench Tiger Reserve, Madhya Pradesh.
(wildlife Institute of India, Dehradun, 2019) Pragatheesh, A.; Rajvanshi, Asha; Mathur, V. B.
The construction of roads and railways change the natural landscape along the entire length of the road, or railway line, apart from fragmenting the landscape. Compared to national highways, narrow country roads have more intense network ad its penetration into the wild habitat is deeper and the adverse effect is therefore manifold as compared to a single national highway. mobility of people and transportation of goods is an integral component of globalization and economic opportunity, road infrastructure that enhances connectivity among people also results in increased habitat fragmentation which is recognized as the largest single threat to biological diversity
Ecological impacts of anthropogenic pressures on high altitude forests along Bhagirathi catchment.
(Wildlife Institute of India, Dehradun, 2001) Awasthi, Anjali; Rajvanshi, Asha; Rawat, G.S.
The forests of Bhagirathi catchment in Garhwal Himalaya (Uttaranchal) have faced anthropogenic pressures since pre-British period. However, human induced disturbances increased during British period when the commercial exploitation of these forests started. It was during this period that the cultivation of potato and apple orchards were introduced in the region. These initial phases of transformation paved way for more recent changes in land-use practices and degradation of high altitude forests. The modern phase of degradation started with the construction of road to Gangotri in the middle of 20th century and opening up of Garhwal for tourism which led to development of infrastructural facilities and influx of mass tourism in the inner valleys. These added pressures on the remaining forests of Bhagirathi valley. 2. Ecological impacts of anthropogenic pressures and patterns and processes of forest degradation have not been quantified in this valley so far. Therefore, the present study was carried out in a part of the Bhagirathi catchment (78015' to 790 E long. & 30030' to 31 008' N lat.). The objectives of the study were: to assess the resource use patterns of villagers, transhumant communities and tourists, to assess the impacts of anthropogenic activities on forests and wildlife and to detect changes inland-cover classes over time and space. The study area is visited seasonally by various transhumant communities who also depend on the surrounding forests for a period of about six months. Four forms of transhumance viz., Nomadism, Semi-nomadism, Transmigration and Nuclear Transhumance were identified in the Bhagirathi valley. -Nomadism is followed by Gujjars, semi-nomadism by Gaddis, transmigration by Jadhs and Garhwalis and Nuclear transhumance by resident Garhwalis. Nomadic people have temporary hutsat both summer and winter settlements whereas transmigrants have permanent houses. Seminomadic and nuclear transhumants have one temporary and one permanent settlement. The impact of 'resource extraction by locals, transhumant communities and tourists on the forests was assessed. It was found that forests located close to villages (zone-I) and temporary settlements (zone-III) were under high lopping/cutting pressure.
Ecological impacts of roads on mammals and integrity of the Central Indian Tiger Landscape
(Wildlife Institute of India, Dehradun, 2023) Saxena, Akansha; Habib, Bilal; Rajvanshi, Asha
Road networks are increasing at an alarming pace worldwide, but most rapidly in developing countries like India. The drivers of road building in such countries include the need to make the benefits of development accessible to citizens in the remotest corners. However, road building in ecologically rich and sensitive regions can have severe repercussions for the wildlife in these regions. Road construction leads to destruction of habitats and physically disconnects previously contiguous landscapes. Traffic on roads directly cause wild animal mortality, cause changes in behaviour of wildlife by altering patterns of space use, and in the long-term can cause populations to diminish through either loss due to mortality, or by isolation of neighbouring populations by creating a barrier to their movement. Through this study, I aimed to understand the responses of a large mammal community to road-related disturbance through different methods, and form a basis for identifying and prioritising road stretches for mitigation of impacts on the large mammal community. The study was based in the central Indian tiger landscape which has one of the greatest potentials for long-term tiger conservation in the country, and at the same time is also facing incremental rates of road infrastructure development. The focal study species included the tiger, its co-predators and primary prey. The study is the first long-term research on the ecological impacts of roads conducted in an important tiger conservation landscape. It has direct management implications for understanding varied species responses to roads, mitigation requirements at different road types and forest protection types, and for landscape-scale prioritisation of sites for mitigating barrier and collision risk.
Toads on Roads : Effect of Linear Barrier on the Movement Ecology of Common Asian Toad (Duttaphrynus melanostictus)
(Wildlife Institute of India, Dehradun, 2015) Sharma, Preeti; Das, Abhijit; Rajvanshi, Asha
Amphibians in India are threatened by population decline and extinction. Conservation efforts are hindered by scanty knowledge on their movement pattern, habitat use and dispersal. Thus, I conducted first ever radio telemetry study on an Indian Amphibian species in Krishnan kovil, a village in Virudunagar district in Tamil Nadu state of India. The study was conducted over a stretch of 1.5 km on both sides of Kollam-Thirumangalam highway (NH 208). The objective was to know if there is any effect of road on the movement and population abundance of Duttaphrynus melanostictus, commonly known as common Asian toad. Reason for selecting a widespread perianthropic species is that such species can better indicate how gene flow is structured in an urban landscape. Total 9 adult individuals (5 ~ and 4 c)I) were tracked ranging between 12 to 41 days from February 1 - April 9, 2015. Findings of the study revealed that NH 208 has a significant effect (estimate 0.007589; standard error 0.003108) on linear displacement of toads that increases away from the road. However in case of village roads the linear displacements were higher near to the roads (estimate -0.01569; standard error 0.002977). This indicates that NH may be affecting the movement of amphibians as a potential physical barrier. However, village roads still seem to be permeable by the toads as they are using it for movement. Orientation data shows no significant orientation (Chi square value 1.19, P value 0.55) of movement of the toads. However, field observations show that movement of toads with NH was always along or away but never across it. Home range estimates show that animal # 6 (NHR6M) used largest home range of 4262.92 sq. meters and showed maximum linear displacement in one night up to 333m. Another aspect of the study was to determine effect of NH on population abundance of common Asian toad. I conducted mark recapture studies in one hectare plot at three sites. The abundance estimates are 228.97 (S.E. 14.09) individuals per hector for site 1, 125.59 (S.E. 9.68) individuals per hector for site 2, 365.94 (S.E. 46.85) individuals per hector for site 3. Abundance estimates at the 3 sites show an increasing trend with the increasing perpendicular distance from the NH. This indicates that the road may have an effect on the population of Duttaphrunus melanostictus. The study is limited to only one non breeding season (3 months), thus, is biased towards movement in less activity period. The study provides hitherto unknown information on toad movement with respect to linear barrier. Such studies are useful in developing realistic, predictive models useful for mitigation and restoration of dispersal corridors in a rapidly changing urban landscape. Results of this first ever amphibian radio telemetry study from India add to a new dimension in Indian amphibian research- beyond taxonomy.