Habitat utilisation of animals and their parastic burden with special refference to elephant in Vazhachal Forest Division , Kerala, South India

Abstract

An investigation was carried out in Vazhachal Forest Division, Kerala, South India during 1994-95 to identify the habitat utilization and seasonal movement patterns of the wild elephants (Elephas maximus indicus). Estimating the population of elephants, finding out the impacts of elephants on woody vegetation, identifying the internal parasites of elephants, studying the need and type of mineral supplements and assessing the importance of Vazhachal as a zone of tourism were also aimed by this study. Habitat utilisation and seasonal movements were studied by indirect methods based on dropping count. Population was estimated by a direct simultaneous count. Vegetation damages were assessed by demarcating plots of size 25x25 m randomly in the study area. Parasitic analysis of fresh dungs was done by centrifugal sedimentation technique and microscopical examination. Mineral mixtures of different concentrations were placed in the area to study the preference for minerals. Data on income from Vazhachal was collected to assess the importance of Vazhachal as tourism centre. Seasonal movements reflected the habitat utilization patterns. Preference of habitats by elephants varied with season. Moist deciduous forests were preferred most in winter season whereas it was least preferred in summer. Evergreen forests were preferred over the moist deciduous forests only during summer season. Acacia plantations were most preferred in summer seasons and was least preferred in first rainy season. Preference for teak plantations were comparatively high during summer and first rainy season. A seasonal movement from thickly vegetated east end of the division to open and secondary forest dominated west end was evident. Great variations in dung densities of individual transects indicated a continuous movement of elephants in the study area. Elephant population at Vazhachal comprised of 155 elephants with a sex ratio (male : female) of 1:6.5 and a crude density of 0.38 elephant/km2. Debarking and breaking tops were the main forms of damages in Teak (Tectona grandis), Papitta (Pterocymbium tinctorium) and Albizia (Albizia falcataria) plantations. Breaking of tops and pushing over accounted for main damages in Bombax (Bombax ceiba) plantations. Damages were comparatively less in moist deciduous and evergreen forests. A total of 35species were found to be debarked in whole of the study area. Elephants preferred mineral mixture with high concentration of minerals and this stresses the need of supplementation of required minerals. Majority of the dungs analysed showed the presence of parasites strongylus and tape worm, indicating heavy infection. Increase in income from tourism in Vazhachal indicates the increasing importance of Vazhachal forests in the tourism map of Kerala. The tourist influx was found to vary with changes in rainfall pattern.