Theses and Dissertations
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Item Habitat selection of birds in New Forest, Dehra Dun, India.(Wildlife Institute of India, Dehradun, 2007) Mohan, Dhananjai; Johnsingh, A.J.T.The New Forest campus is primarily a man-made ecosystem created in the 1920s mainly to house the Forest Research Institute. Much of the area of what is New Forest today was under agricultural fields till they were acquired in 1920s by the British and there after considerably large areas of this sprawling campus were developed into demonstration forests, gardens, experimental plantations areas, and arboretum by planting them up. In addition, there is a block of natural forest on the northern part of the campus which belongs to 3C2b(i) type (Moist Bhabhar Sal forests). The present study was restricted to ca. 150 ha of wooded part of the 463 ha of the campus. Two hundred and seventy six birds have been reported from the campus till date. The campus is managed through management plans prepared at a ten year cycle. Four distinct vegetation types were identified in the wooded parts of the New Forest campus based on the vegetation composition and structure. These, namely, Chir Pine plantations, Gardens, Mixed plantations and Natural forests were recognized as the four distinct habitats for the birds, the first three being man-made. The bird abundance was estimated by conducting point transects which were done over a two year period from October 2004 to June 2006 and collected habitat structure and composition data by laying out vegetation plots around the point locations for the bird transects (bird centered vegetation sampling). The guild structure of the birds of New Forest was investigated and factors determining it were identified. The seasonal change in guild structures both within and across various habitat types was also looked into. Birds were divided into fifteen fine feeding guilds. A distinct habitat selection by birds was observed amongst the four identified habitats of New Forest as seen from multiple response permutation procedure (MRPP) and hierarchical clustering of sample points in different habitats on the basis of bird composition. The present study shows that despite some degree of biotic pressures, natural forest habitat still possesses the highest bird richness as compared to the well-preserved mature plantations even with mixed crop. It also supports the highest density of birds of all the habitats of New Forest. The highest number of indicator birds has also been reported from this habitat. A large number of biome restricted bird are reported from this habitat which has led to the declaration of New Forest as an Important Bird Area. This habitat which is typical of northern part of Dehradun valley is under great threat in most parts owing to a rapid spread of urbanization and the patch in New Forest may be the only one to provide long term preservation to its typical flora and birds.Item A study on the vegetation of shivaliks and outer himalaya in Dehradun dun district Uttar Pradesh(Wildlife Institute of India, Dehradun, 1996) Bhaisora, N.S.; Rawat, G.S.The subtropical zone or Bhabar tract in north India, characterized by fertile alluvial plains (Doons) and fragile Shivalik hills of Tertiary period, lies between the Upper Gangetic plains and outer Himalaya revealing the floral and faunal affinities with both the regions. Extensive cultivation, dense human population, industrial developments and livestock grazing in this area has caused fragmentation and degradation of forests. Of about 40,000 km2 only < 2000 km2 area has been brought under protected area (PA) coverage e.g., Rajaji and Corbett National Parks. The remaining forests continue to degrade. 2. Sal (Shorea robusta), a commercially "important tree, IS considered as climax species in this tract and has been studied extensively. However, there is a paucity of information on the overall conservation status and regeneration of forests in this area. Therefore present study was, undertaken with the following objectives: i) to study the structure and composition of the woody vegetation (tree and shrub layer) along the gradients of altitude and human use in Shivaliks and outer Himalaya, ii) to study the species diversity and human-animal use patterns in various zones, and iii) to assess and compare the regeneration status of Sal and associated tree species in the Shivaliks and outer Himalaya. 3. The study was conducted within about 500 km2 area in the lower parts of Debra Dun district, Uttar Pradesh (290 57' to 310 20' N lat and 770 35' to 190 20' E long). The study area also included parts of western Rajaji National Park, westerns Shivalik Forest Division, forests in Doon Valley, protected forest patches adjacent to Wildlife Institute of India (WII), Indian Military Academy (IMA) , Forest Research Institute (FRI), Upper parts of Rajpur, Malsi and mine reclamation sites near MussoorieItem Species interactions with in mixed species bird flocks along an Elevational gradient in the Western Himalaya.(Wildlife Institute of India, Dehradun, 2021) Gokhale, Pranav; Kumar, R.S.; Mohan, D.Mixed-species bird flocks (hereafter, “flocks”) are an interactive community of largely insectivorous birds, which move and forage together to gain enhanced access to resources and protection from predation. In this study, I aimed to investigate a question: do interspecific interactions within mixed-species flocks change along an elevational gradient? To test this, I carried out this study in the Garhwal region of the Western Himalaya in Dehradun District, Uttarakhand from January to April 2021 (spanned across two seasons). The study areas comprised of three field sites along an elevation gradient from western part of the Rajaji Tiger Reserve (300 m ASL) to Mussoorie (2200 m ASL). I sampled flocks and relative abundances of birds on the two pre-existing trails in each of the three field sites. I walked each trail 10 to 13 times. I recorded species identity, group/cluster size of all birds seen inside as well as outside flocks on the trail and within 10 m on either side of the trail. I assessed arthropod prey availability in winter for the flocking species by using branch bagging technique on the same trails. In total, I clipped 150 branches for the three elevations. I calculated species-specific flocking propensity for each elevation from the information on birds seen within and outside flocks. I used network density (potentially realised associations) and weighted degree (associated strength) to quantify the interspecific interactions (associations) within flocks. To control for the influence of species availability on flock network properties, I generated null flocks using an abundance-based null model. I recorded 80 flocking species in 412 flocks, of which, 179 flocks were observed at the High elevation, 156 at the Mid elevation and 77 at the Low elevation. Majority of species in the Western Himalayan flocks were insectivorous gleaner. I found insect prey availability (resource) to decrease with increasing elevation in winter. As expected, flocking propensity, network density and weighted degree increased with elevation in both seasons indicating greater potentially realised associations and high strength of associations between species. Interestingly, the Low elevation flocks disintegrated completely at the onset of summer possibly due to the greater availability of resources, or an upward migration of species for breeding. I did not analyse the Low elevation flocks in summer due to small sample size (n=5). Flocking propensity and network density decreased from winter to summer at Mid and High elevation while, weighted degrees decreased only for the Mid elevation. This is likely that true summer may not have started at the High elevation during the course of my fieldwork. To conclude, with increasing elevation in both seasons, species not just flocked more, but associated with many species and these associations became stronger, potentially due to the scarcity of resources. It is possible that species may not be able to access resources efficiently when foraging on their own at the High elevation, compelling them to participate in flocks to avail complementary benefits from many other species.Item Making the Urban Matrix Matter : Characteristics of the Avifaunal Community of the Urban Matrix Relative to the Urban Green Spaces of Dehradun(Wildlife Institute of India, Dehradun, 2021) Coutinho, Jason Bismarck; Onial, Malvika; Kaushik, MonikaUrban ecology is a field in science which deals with understanding the ecological synergies within urban systems. This is a relatively new field which started out when ecologists recognized the importance of quantifying human impacts on ecosystems globally. This field is ever so pertinent now that no ecosystem remains which doesn’t have human induced changes. 2. Urban ecosystems are dynamic ecosystems with interactions similar to those of natural ecosystems, but they are also directly influenced by the culture, politics, economics and social organization of human society. Urban has different definitions all over the world with no single consensus and such disparities make it impossible to compare ‘what is urban’ across the globe. Simply urban areas are cities and suburban areas with the landscape being called as the ‘built environment’. Urbanization and the urban sprawl have impacted not only the land covers across an urban area, but also the biodiversity in it. This urbanization filters the biological community at various levels and it is pertinent that we understand this filtering. 3. The urban landscape can be divided into two major categories for simplicity. The urban green spaces are terrestrial areas, both public and private covered with vegetation, made available to users. These are very important to the health of the city. They enhance the wellbeing of the people in the city and also are habitats for urban wildlife. The urban grey on the other hand is the ‘built’ or ‘artificial’ environment. This is usually seen increasing as we reach the center of a city or urban area. 4. The urban matrix is a mix of the greens and the grey and has no clear definition. It is all the habitat patches in the urban landscape that lie outside the urban green spaces. This urban matrix is highly dynamic and every urban area has its own unique habitat mosaic. This important matrix however has not been studied extensively. In most areas of urban ecological research, the matrix’s relevance is undervalued. The current study was conducted in the city of Dehradun from March 2021 to April 2021. To understand the importance of the urban matrix’s contribution in maintaining an urban areas biological diversity, this study aims to quantify the avifaunal community in the urban matrix. Further it looks to understand the relevance of the avifaunal assemblage characteristics of the urban matrix relative to that of the urban green spaces. 5. To study this, the patterns of the avifaunal community in Dehradun were explored. Fundamental properties of biological communities like species richness, abundance, density and composition were looked at the habitat scale. At the landscape scale, potential habitat correlates of the species richness and density were studied so as to shed some light on the factors and processes that might be driving the community assembly in the urban matrix. The comparison of the avifaunal assemblage was done by comparing the overall richness, density and composition in the urban matrix and urban green spaces. 6. In the urban matrix, 109 sampling units were laid and then sampled using a variable radius point count method. A total of 3775 individuals belonging to 81 species were recorded. Feral Pigeon was the most dominant species, habitat-wise species richness was maximum in the built – up areas (54 species) and species density was maximum in scrublands (13.12mean ± 4.35SD per hectare). Ordination graphs showed that plots of green cover were dissimilar from the other habitats. The species richness in the urban matrix was positively influenced by the increasing proportions of open areas and scrublands. Built – up had negative influence on the species richness but showed peaking at moderate levels of human development. Density in the matrix was positively influenced by increasing proportion of scrublands and the landscape heterogeneity. It was negatively influenced by increasing proportions of built – up and green cover. Comparisons of the richness and density of the urban matrix and urban green spaces showed that there was a huge difference in both the parameters, with urban green spaces showing higher values for both. The species composition Venn diagram showed that the matrix and urban green spaces share 64 species among them, with the urban green spaces and urban matrix showing 50 and 17 unique species respectively. 7. In general, the current study shows the relative importance of the urban matrix in maintaining the urban biodiversity and the need of conserving the habitats in the matrix to boost the urban biodiversity.