Distribution and Diversity of Storks in the Adjoining Areas of Chitwan National Park, Nepal

Abstract

The Barandabhar corridor forest (BCF) has a very high biodiversity and in terms of wildlife is globally significant. This study on the status of Ciconiidae (storks) in the BCF was conducted by means of direct observation along bird routes, line transects, roads, man-made tracks and riversides. A seasonal count was used to determine the actual status of the storks. Four species of the family Ciconiidae, the lesser adjutant stork (52 individuals); black stork (6); woolly-necked stork (148) and Asian open bill stork (363) were recorded during the course of this study. The population of storks was highest in the rainy season. Among the species studied, the Asian open bill stork, woolly-necked stork and lesser adjutant stork were resident in the area, whereas the black stork is migratory and only present in winter. Storks were recorded mainly around lakes and ponds (675 individuals) followed by marshy and swampy land (325), grassland (293), paddy fields (251), rivers and streams (187). The most abundant species is the Asian open bill stork, followed by the woolly-necked stork, lesser adjutant stork and black stork. All the diversity indices values showed that the Asian open bill stork was the dominant species in the study area, followed by the woolly-necked stork, lesser adjutant stork and black stork. Many wetlands inside the Chitwan National Park and the Barandabhar corridor forest dry out in summer, which directly affects the survival of these birds, as they are confined to protected areas in the dry season, when there is no water in the paddy fields. Degradation of aquatic ecosystems, overuse of pesticides in fields and over-fishing of rivers and lakes using poisons and electricity, are the major threats to these species.