Species Diversity and Environmental Correlates of Farmland Dependent Birds in Nawalpur,Nepal

Abstract

The increase in change in farming practices, result in habitat destruction or alteration, the greatest threats to biodiversity. Birds found around or in the farm utilizing different crops for foraging and some nesting in the hedges near the farm area are known as farmland dependent birds. Bird richness in agricultural lands are considered to be a good indicator for good state of wildlife and healthy condition of plants and invertebrate on which they feed. This study aims to explore the species diversity and environmental factors affecting the diversity of farmland dependent birds. Data was collected from the centroid point of the randomly selected 72 grids of size 500m by 500m. The birds were recorded at the circle of 50m radius for 20 minutes by using visual encounter method. The environmental variables (distance to nearest forest, distance to nearest water body, distance to nearest tree, distance to nearest village distance and number of people presence) were also collected within the circle. The data was analyzed using standard statistical tools. Generalized linear model (GLM) was performed to examine the relation of birds with different environmental variables. A total of 123 bird species were recorded in the farmland of Nawalpur during this study, where eighty three species in summer season, seventy seven species in rainy season and sixty nine species in winter seasons were recorded. The species diversity was higher during summer than rainy and winter. The significant impact in species richness of birds with distance to nearest forest, distance to nearest water body, precipitation (mean) and temperature (mean) was found. Distance to nearest forest, distance to nearest water body, precipitation (mean) have negative correlation with species richness in all three season but temperature has positive association with species richness in all three season whereas distance to highway has positive correlation with species richness in winter seasons. Distance to village was not important compared to other factors for bird diversity. Thus farmland of Nawalpur supports higher species richness of farmland dependent birds.