Ecology of the asian elephant in southern India. I. Movement and habitat utilization patterns

Abstract

The movement and habitat utilization patterns were studied in an Asian elephant population during 1981-83 within a 1130 km² area in southern India (11° 30° N to 12° 0' N and 76° 50' E to 77° 15' E). The study area encompasses a diversity of vegetation types from dry thorn forest (250-400 m) through deciduous forest (400-1400 m) to stunted evergreen shola forest and grassland (1400-1800 m). Home range sizes of some identified elephants were between 105 and 320 km². Based on the dry season distribution, five different elephant clans, each consisting of between 50 and 200 individuals and having overlapping home ranges, could be defined within the study area. Seasonal habitat preferences were related to the availability of water and the palatability of food plants. During the dry months (January-April) elephants congregated at high densities of up to five individuals km⁻² in river valleys where browse plants had a much higher protein content than the coarse tall grasses on hill slopes. With the onset of rains of the first wet season (May-August) they dispersed over a wider area at lower densities, largely into the tall grass forests, to feed on the fresh grasses, which then had a high protein value. During the second wet season (September-December), when the tall grasses became fibrous, they moved into lower elevation short grass open forests. The normal movement pattern could be upset during years of adverse environmental conditions. However, the movement pattern of elephants in this region has not basically changed for over a century, as inferred from descriptions recorded during the nineteenth century.