Habitat characterization of Asian elephant (Elephas maximus) in Wayanad wildlife sanctury, Kerala

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Date
2018
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Department of Wildlife Sciences College of Forestry, Vellanikkara
Abstract
A field study was conducted to characterise the habitat of the Asian Elephant (Elephas maximus). The study was conducted from September 2017 to April 2018 in Wayanad Wildlife Sanctuary, Kerala. A total of 100 transects were walked randomly across different vegetation types of Wayanad Wildlife Sanctuary to obtain elephant population density through dung count method across two separate seasons, wet season (Oct-Nov) and dry season (Mar-Apr). Vegetation parameters of these areas were also recorded in a total of 600 quadrats of size 10m × 10m. Socioeconomic survey of local communities around the sanctuary and forest officials was also conducted through an interview schedule to understand the perception towards human-elephant conflict. Seasonal movement of Asian Elephants was observed in the sanctuary as characterised by the difference in population density during the wet season (0.68 elephants/km 2 ) and the dry season (0.87 elephants/km 2 ). Elephant density was higher in the dry season. There was also variation in density of elephants between different ranges across the two seasons. Sulthan Bathery recorded highest elephant density of 0.87 elephants/km 2 in the wet season, while Muthanga recorded highest elephant density of 1.03 elephants/km 2 in the dry season. All ranges except Sulthan Bathery recorded increase in elephant density during the dry season. Elephant population density also varied between different vegetation types. Density was highest in the natural forests, consisting mainly of mixed moist deciduous habitat and mixed dry deciduous habitat in both seasons. Percentage distribution of elephants was found to be higher in natural forests (84.26% and 74.09% in wet and dry seasons respectively) than in plantations (16.74% and 27.91% in wet and dry seasons respectively). Therefore, it can be deduced that elephants prefer natural forests over plantations. Hence, the declining area of natural forests could be a cause of concern for long-term conservation of the Asian Elephant in Wayanad. This could also be a reason for the escalating incidence of human-elephant conflict in the area. Vegetation studies using quadrat surveys showed a total of 67 species of trees within 33 families. The density of trees was calculated to be 420 trees/ha. Density of trees was slightly higher in plantations (432 trees/ha) than in natural forests (418 trees/ha). Tree species such as Terminalia elliptica, Tectona grandis, Anogeissus latifolia, and Lagerstroemia microcarpa were found to be the most abundant in the sanctuary. Girth class distribution of tree species followed a skewed distribution indicating that the habitat is not in a stable condition due to lack of regeneration. Restoration efforts should be done to ensure the long-term survival of the forests of Wayanad Wildlife Sanctuary. Diversity indices such as Shannon-Wiener Index and Simpson’s Index showed an rather low diversity of tree species in the sanctuary, with higher diversity in natural forests than plantations. Correlation between elephant density and tree species diversity was found tobe highly significant only during the dry season. This could imply that tree species diversity influences elephant distribution during the dry season. The Important Value Index was computed from relative density, relative frequency and relative basal area to show quantitative relationship among the vegetation and to highlight the importance of families of trees within a habitat. Important Value Index (IVI) values shows that the most important families of trees in the sanctuary are Combretaceae, Fabaceae, Lamiaceae and Lythraceae, which include trees preferred by the elephants as browse species. Interview schedule of local communities and forest officials shows that that there is a highly significant and strong relation between the response of the two groups (local communities and forest officials) towards their perception about the change in land-use systems, change in climate, and factors related to human-elephant conflict and conservation strategies. The expansion of human population to the wildlife habitats, reduction in the availability of food and water in the forest, cultivation of palatable crops in the agricultural lands surrounding the sanctuary, lack of proper planning in establishment of the preventive measures and inadequacy of compensation associated with the long term process for availing compensation were found to be the major causes for human elephant conflict. Increased incidence of crop damage during summer can be an indirect indicator of movement of elephants into the sanctuary from the adjacent bordering protected areas, as well as presence of palatable fruit trees like Jack and Mango. Proximity of farming areas among respondents to the forests were recorded at a higher percentage in Muthanga and Tholpetty range, which could influence elephant movements into these areas during the dry season. The quick interventions by the forest officials, cultivation of repellent crops at greater distance from forests, and understanding the predictable behavioural changes of wild animals can help reduce the risk of human-elephant conflict to a great extent. Better implementation of the preventive measures can encourage the local communities residing in the sanctuary to ease the situation of human elephant coexistence.
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Master of Science in Forestry
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