Seasonal Crop Raiding of Fruit Trees by Asian Elephants: An Insight into Foraging Preferences from Croplands Abutting Bannerghatta National Park, Bengaluru, Karnataka, India

Abstract

This study was undertaken to evaluate factors which potentially influence crop depredation by Asian elephants during the non-cropping season. The study was conducted in a 2.5 km zone abutting Bannerghatta Wildlife Range of Bannerghatta National Park, Karnataka. Three fruit trees which are commonly raided by elephants, namely jackfruit (Artocarpus heterophyllus), mango (Mangifera indica) and tamarind (Tamarindus indica) were selected for the study. The convenient sampling approach was adopted to map individual trees of the three species between May and July 2015. Factors such as the phenological stage, the parts of the tree foraged, the distance from the Park boundary and the crop clustering pattern were recorded. Among the 1368 mapped fruit trees, only 4.31% (n = 59) of the trees were found foraged on. However, 79.66% of the damage occurred in trees that were fruiting. There also seemed to be a preference in fruits foraged; A. heterophyllus had the highest damage (8.84%), followed by T. indica (4.20%) and M. indica (3.66%), and the preference ratios for the three species were estimated to be 2.05, 0.97 and 0.85, respectively. The analysis showed that the spatial foraging pattern was also species dependent, with damage in        A. heterophyllus and M. indica recorded at distances more than one km from the Park unlike in the case of T. indica. Refuge cover availability and forage quantity measured through clustering pattern, was not found to positively increase foraging preference. It was also observed that damage in fruiting M. indica were more common in areas which contained both A. heterophyllus and T. indica within 100 m, than areas which had either none or only one of the species present. Spatial analysis revealed a concentration of foraging in the north-western and south-eastern portions of the National Park. Results obtained in the study aided in identifying the indicative factors which influence the crop foraging pattern during the non-cropping season. A detailed long-term study on the foraging ecology of elephants in other human-dominated regions will help strategize effective human-elephant conflict mitigation measures.