Putrescible Waste Landfills as Bird Habitats in Urban Cities: A case from an Urban Landfill in the Colombo District of Sri Lanka

摘要

As putrescible waste landfills are reliable and rich sources of food, these man-made habitats can support large populations of avifauna composed of different feeding guilds. Unusually high population inflations of few opportunistic species of birds could impose a severe impact on the overall ecological balance. We studied the bird community in an open waste dump located in a highly urbanised area in the Colombo District, Sri Lanka. Bird census were performed using block counts in two contrasting sites of the landfill i.e., active dumping area and inactive dumping area between April 2015 and March 2016. Abundance and density of birds were significantly higher in the active dumping area than in the inactive area. The inactive dumping area accounted for the highest avifaunal richness, diversity and evenness. Bubulcus ibis and Corvussplendens were the dominant species at the active dump, and their foraging and social behaviors probably discouraged other bird species from exploiting food resources in the dump despite belonging to different feeding guilds. The forging bird community at the landfill exhibited seasonal variations in abundance and other interspecific interactions. Since the influx of large numbers of birds to landfills can potentially cause numerous environmental issues in urban areas, the current study highlights the importance of study of the seasonal patterns of bird communities in relation to location and management of landfills.