Presentation on theme: "Elephant distribution and habitat preferences in the Western Ghats of Karnataka from the available direct and indirect evidences PRESENTED BY: DR. CHITTARANJAN."— Presentation transcript:
Elephant distribution and habitat preferences in the Western Ghats of Karnataka from the available direct and indirect evidences PRESENTED BY: DR. CHITTARANJAN DAVE AND SHIVAM TRIVEDI
Elephants - Elephantidea Two species Asian elephant (Elepha maximus) African elephant (Loxodonta)
Asian elephants – An introduction India has largest population (60%) 28000 - 30000 (2012 census data) Range shrunk from 9 to 4.9 million km 2 In India elephant range area - 110000 km 2 Schedule – 1 in WPA and endangered – IUCN 28+2 elephant reserves Foothills of Himalayas (1700) North Eastern states (9000-9500) Andaman Islands (40) Western and Eastern Ghats (14000) East central India (2650)
Asian elephants - Habitat Dependant on the wetter mixed deciduous and semi-evergreen forest Gray, T. N., & Phan, C. (2011) Waterbodies important habitat and elephants use habitats close to permanent waterbody Sukumar, R. (1989) and Gaugris, J. Y., & Van Rooyen, M. W. (2010) High human density area and surrounds also preferred Garcia, C. A., Bhagwat, S. A., Ghazoul, J., Nath, C. D., Nanaya, K. M., Kushalappa, C. G.,... & Vaast, P. (2010)
Asian elephants - Threats Linear developments (roads and rail lines) Habitat fragmentation/ loss Infrastructure development Illegal capture of calves Ivory poaching Baskaran, N., Varma, S., Sar, C. K., & Sukumar, R. (2011) and Singh, A. P., & Sharma, R. C. (2001)
Objectives Whether elephants are randomly distributed in the area Which vegetation type is intensively used by elephants? Whether elephant distribution has any effect of factors like habitation, roads, waterbodies and fire If yes then which parameter has overriding effect on elephant distribution?
Datasets Secondary data Elephant location LULC of study area Fire data (2008 to 2010) SRTM data for elevation Digitized data Roads Habitation (villages)
Methodology Elephant data – QGIS - Projection NN method – Avg. dist b/w 2 elephants MCP – Individual elephant location Buffer – Avg. distance b/w elephants Load vegetation map Clip vegetation map using AOI Point in polygon function – no. of elephants in each veg. class Generate random points in AOI Export/ add geometry tool – Area of each veg. class Field calculator – Density of observed and expected elephant occurrence XY tool – Export both occurrence – Elephant distribution pattern Statistical analysis – Chi sq. test
Methodology Load Bing map layer Create shapefile – Village location and road map - Projection Fire data (2008, 09, 10) – Merge shapefiles Add waterbodies – Intersect with AOI Calculate min. dist. of elephants from fire, road, water and villages Statistical analysis – Paired t-test assuming unequal variance Calculate min. dist. of random points from fire, road, villages and water
Elephants using different vegetation types Sr. no.Landuse typeObservedRandomTotal 1 Non-forest\Agricultural134 2 Wet evergreen secondary or disturbed forest257 3 Forest plantation9413 4 Secondary moist deciduous forest132134 5 Primary moist deciduous forest and degradation16824 6 Wet evergreen primary forest 00 7 Treesavanna to grassland in dry zone00 8 Water body00 Chi square testP > 0.05
How elephants are responding…… Sr. no.Test typeFireWaterbodyVillageRoads 1 t Stat-0.13556-2.18024-2.069024668-3.36764 2 P(T<=t) two-tail (assuming unequal variance) 0.8925140.0321780.0421855180.001192 Sr. no.Analysis typeFireWaterRoadVillage 1 Mean1645.037006.69889.031559.01 2 Standard Error+144.29+715.02+163.78+135.82 Mean distance (m) from elephant location to various parameters
Conclusion Elephants are not randomly distributed and have a pattern of habitat preference They seem to occur largely in primary moist deciduous and forest plantation Elephants respond to the presence of waterbody, village and roads but not to fire locations or burnt areas. Waterbody and terrain ruggedness along with vegetation type explains the current distribution pattern in the study area.