Composition of Avian Communities in a Human-modified Wetland Okhla Bird Sanctuary, India: With Notes on Conservation Initiatives

摘要

Monitoring of avian community composition in different landscapes are being emphasized from environmental monitoring perspective. Okhla bird sanctuary is an important bird area and has widest flood plains along the stretch of river Yamuna flowing through National Capital Region, India. At the same time, this sanctuary is under tremendous pressure particularly due to encroachment, unsustainable harvesting and pollution. Present study was carried out in Okhla bird sanctuary from July 2004 to June 2005 to assess the species composition and richness of the avifaunal community along with their seasonal variation. A total of 126 species belonging to 18 orders and 44 families were recorded. The avian species richness was highest for the order Passeriformes followed by Charadriformes, Anseriformes, Pelicaniformes and others. Anatidae was the most diverse avian family in the study area. Species richness of avifauna was highest in January (83 species) and least during July (37 species). This wetland supports good number of resident (86 species) and migratory birds (40 species). Most avian species (41.27%) were found to be wetland-dependent followed by wetland-associated (34.13%) and terrestrial (24.6%) birds. Kruskal–Wallis test revealed significant variation in the number of migratory and wetland-dependent species in different seasons. This study emphasize the importance of Okhla bird sanctuary for resident and migratory, as well as, terrestrial, wetlandassociated and wetland dependent birds and thus contribute towards the existing knowledge of the seasonal pattern avifaunal composition of this wetland. Long-term monitoring of avifaunal composition over the years is an excellent means to assess the health of this waterbody and thus might be useful to foster its sustainable improvement.