Theses and Dissertations
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Item Ecology and ranging behaviour of Elephants, Elephas maximus, and its implications for managing human-elephant conflict in Chhattisgarh, India(Wildlife Institute of India, Dehradun, 2022) Lakshminarayanan, N.; Pandav, BivashIn the East-central region of India that supports the smallest regional elephant (Elephas maximus) population, the elephant ranges have expanded in northern Chhattisgarh (erstwhile eastern Madhya Pradesh) since late 1980s. Chhattisgarh was carved out of Madhya Pradesh during the year 2000, and thence, the State has been witnessing elephant range expansion and concomitant population growth resulting in acute human–elephant conflict. Over 60 human lives are lost every year due to human–elephant conflict, and the trend is only increasing. Chhattisgarh scenario represents challenges facing management of elephant populations undergoing environmental dispersals that typically result from saturated habitat conditions in the elephant home ranges. In response to the prevailing conflict situation, the study aimed to understand facets of elephant ecology and aspects of human–elephant conflict to generate management perspectives. Historic information available as fragments in literature indicates that elephant distribution in the whole of East-central region was marked by both range expansions and local extinctions during the last one century. In particular, the contemporary phenomenon of elephant range redistribution in the East-central region peaked after 1980s, and coincides with large-scale human-induced disturbances to the formerly intact elephant habitats in the region. There were also pull factors like creation of pseudo-habitats (providing only cover for elephants) through forestry operations that possibly attracted elephants to human–dominated areas perpetuating human-elephant conflict. In Chhattisgarh, the elephant distribution during the period 2012 to 2017 was reported from 16 Forest Divisions and four Protected Areas in the north and north-central regions of the state. The elephant population, as enumerated by Chhattisgarh Forest Department during 2021, ranged from 250 to 300.Item Ecology of elephants (Elephas maximus) and their interactions with humans in south West Bengal, India(SACON, 2023) Singh, Akriti; Kumara, H NThe thesis delves into the intricate dynamics surrounding the range expansion of Asian elephants in South West Bengal, catalyzing heightened human-elephant conflicts. It meticulously outlines the evolution of this phenomenon, starting from the elephants' modest presence in the 1950s to their expansive spread across 13200 km² by 2010–18. Through structured surveys and field observations, the elephants' footprint has been delineated across 163 grid cells in the region, showcasing their adaptability to varied habitat conditions. Central to understanding this expansion is the interplay between habitat factors and elephant presence. The thesis elucidates how the elephants' utilization of grid cells correlates positively with the forest edge, forest area, agricultural area, and barren land. As forests recede and agricultural land expands, elephants find themselves increasingly encroaching upon human settlements, leading to heightened conflict situations. Population estimation methodologies, ranging from dung count surveys to distance sampling, shed light on the elephant demographic in the region. However, the thesis highlights the challenges inherent in accurately gauging elephant numbers, particularly in areas where human activities disrupt their natural movement patterns. Despite these hurdles, the presence of a substantial number of immature elephants signifies a thriving population, albeit one grappling with human-induced disturbances. The thesis also sheds light to the ecological intricacies of elephant habitat use and feeding behavior. By overlaying grid cells on selected elephant habitats and analyzing geo-coordinates, the intensity of elephant habitat utilization was ascertained. The elephants' dietary preferences, encompassing a diverse array of wild plant species alongside agricultural crops, underscore their adaptive prowess in navigating human-altered landscapes. However, this dietary reliance on crops exacerbates conflicts, as elephants frequently venture into agricultural fields, triggering retaliatory measures from local communities.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.Item Dry season forage selection by Asian elephant (Elephas maximus) in a fragmented landscape, northern West Bengal(SACON, 2020) Das, Priyanka; Kumara, H N; Kshettry, AritraThe Asian elephant is a wide-ranging species with just 51% of its range across Asia covered by forest land. Hence, it is imperative to plan conservation action in the other half comprising of multiuse landscapes. With food being an important resource determining elephant use and movement, understanding their forage selection in a heterogeneous landscape can help us prioritise allocation of limited conservation resources. I studied forage selection by Asian elephants during December 2019 to June 2020 in a tea-estate-agriculture-forest mosaic in northern West Bengal, a landscape which typifies land-use mosaics used by elephants across India. Asian elephants in the landscape consumed 132 plant species, of which 21 species constituted 85.3% of the total feeding signs recorded, while non-reproductive plant parts dominated the diet. The mean (±SE) feeding frequency was found to be highest in villages [50.15 (±22.85)] followed by forests [40.51 (±9.42)], semi-open forests [12.14 (±9.42)], tea estates [5.79 (±1.95)] and open forests [3.31(±1.44)]. However, the high variance in village indicates that elephants use villages for movement and forages occasionally. Food grain from household was consumed rarely (0.25%). Overall, they used dicots (52.73%) more than monocots (47.27%) and browse (65.23%) more than herb (34.77%). Elephants consumed more monocots in forests and tea estates whereas in semi-open forests, open forests and villages they consumed more dicots. The availability of monocots was lesser than dicots in all these land use and land cover types. In forest, they consumed more herbs, whereas browse was consumed more in all other land use and land cover types.Item Nutritional Ecology of Asian Elephants (Elephas maximus) in Chilla Range of Rajaji National Park, Uttarakhand(Wildlife Institute of India, Dehradun, 2009) Datta, Suniti Bhushan; Goyal, S.P.; Sathyakumar, S.Responses of animals to the habitat has been the central focus for management of species and of these aspects, nutritional ecology has been the key issue in foraging behaviour studies and habitat studies. Therefore, the study focused on the nutritional aspect of forage selection by Asian elephants (Elephas maximus) in Chilla Range of Rajaji National Park. The main objectives were to determine whether habitat structural heterogeneity or nutritional quality of the selected food plant species was a determinant in the temporal and spatial habitat use by elephants and to determine the reasons behind seasonality in foraging. The study area of 148km2 in Chilla Range of Rajaji National Park was divided into twelve 2x2km grids, and these were further divided into 4 sub-grids each. In each sub-grid, a 1 km long line transect was laid and along this 10m radial plots were placed at 100m intervals. Vegetation data were collected to characterize the habitat structural heterogeneity in terms of number of trees of each species, height of canopy base, canopy volume, percent canopy cover, species diversity, species density and geo-spatial variables such as NDVI, standard deviation of slope, mean elevation and the proximity to water. Parts of 12 most-preferred plant species were collected in the study areas for estimating nitrogen, ash, acid detergent fibre, and macro and micro minerals such as sodium, potassium, calcium, copper, magnesium and zinc. During the study period from December 2008 to May 2009, Elephant response was determined in terms of dung density along the 1km transect in winter and in summer. The total number of trees in each grid varied from 124 to 268. Tree diversity ravged betweel) 0.456-1.454. Height of canopy base was mostly 1.5-3.0 m, although two grids showed extremely high canopy bases. Canopy volume ranged from 165.63m3 to 948.36m3 , although the majority of the grids showed a high variation in canopy volume in terms of standard deviation (SE). The percent canopy cover ranged from 54.13% to 93.72%. Most of the NDVI values were _high in the study area (>0.180), while one grid showed a low value of 0.143. For the standard deviation of slope, the values ranged from a low of 2.46 to a high of 8.46. The mean elevation of the study area ranged froin 391-840m a.s.l. Nutritional values estimated for most of the parameters in winter and summer from selected plant samples collected in the study area showed slight variations 4 between seasons. Percent nitrogen content indicated no seasonal difference (f=0.98, p=0.05, df=ll). The percent acid detergent fibre indicated a difference (P<0.05,df=I I) between the two seasons. Percent ash content was found not significantly different (p=O.l6, p=0.05, df=l1) between seasons. Amongst the macro and micro minerals, sodium content was significantly different across the two seasons. Potassium content was found to be significantly different across the seasons (p<0.05). Calcium content was also found to be significantly different between winter and summer (P<0.05). The copper content could not be compared across the seasons as in summer the levels present in plant samples were too low to be detected by the instrument. The difference in magnesium and zinc content across the two seasons were not significant (p=0.16 and P=0.31). Dung density in the grids across both seasons was non-uniform and highly skewed (p<0.05, df=47). The dung densities in both seasons were related more with the habitat heterogeneity variables than nutritional values obtained in each grid. The relationship between dung density and the number of plants was positive in the winter seasons (R2= 0.2848) and summer (R2= 0.4383), indicating that elephants are highly selective towards areas with higher numbers of woody plants. Plant species diversity indicated no influence on dung density in winter (R2= 0.00005), but showed a negative trend in summer (R2= 0.0154). The height of canopy base was negatively related to dung density, with elephants selecting areas with a mean canopy base height between 1.5-3.0m during both winter (R2=0.2288) and summer (R2=0.174). Dung density showed a negative trend when related to canopy volume in both seasons. The R2 value for winter is 0.2087 and in summer it is 0.1471. Percent canopy cover had a negative influence on the dung densities in winter (R~= 0.083) and in summer (R2= 0.1524). NDVI showed a negative relationship with dung densities in winter (R2=0.01l1) and a positive relationship in summer (R2= 0.1894). The relationship between the standard deviation of slope and dung density showed a negative trend in both winter, (R2=0.0033) as well as in summer (R2=0.0389). The higher elevation grids show a lower d/mg density during both winter (R2=0.216) and summer (R2=O.l443). The relationship between dung density and proximity to water in winter is negative (R2=0.1575) and the relationship remains negative (R2=0.1016) in summer. In relation to nitrogen content and dung density in winter there was a weak positive trend (R2=0.0256), while in summer there was a weak negative trend (R2=0.032). The relationship between dung densities and percent acid detergent fibre (ADF) in winter indicated a weak positive trend (R2=0.0012) and during summer, indicated a weak negative trend (R2=0.0657). In relation to percentage ash content (Fig. 4.29.), dung densities in winter indicated a weak positive trend" (R2=0.0114), while in summer there was a weak negative trend (R2=0.0641). When compared with sodium, dung densities showed a very weak positive trend (R2=0.0092) in winter and a negative trend in summer (R2=0.0834). In winter, when compared with dung densities potassium showed no trend (R2=0.001), but in summer, there was a weak negative trend (R2=0.0076). In winter, calcium does not show any relationship with dung densities (R2=0.0002), while in summer, there is a weak negative trend (R2= 0.0511). Magnesium content does not show any relationship with dung densities (Fig 4.33) in the winter season, (R2=0.0007), while in summer, there is a weak negative trend (R2=0.004). Zinc shows a weak positive trend (R2=0.0298) in winter and a weak negative trend (R2=0.026) in summer. Principal component analysis of nutritional parameters indicated nine components that were influencing dung density distribution in the study area in both the seasons, and hence no single parameter influenced elephant habitat use. The study clearly indicates that the distribution of elephants in Chilla Range of Rajaji National Park is more related to abundance of woody species and proximity of water, than the nutritional content in plant species. Principal component analysis showed that there was no single parameter that influenced dung distribution in the study area. This could be due to the fact that plant species selected for foraging by elephants contained an adequate amount of nutrients in most species for meeting foraging requirements .an d they probably meet their daily requirements by foraging on varied proportions of plant species.