Variation of avifaunal diversity in relation to land-use modifications around a tropical estuary, the Negombo estuary in Sri Lanka

We assessed variation in avifaunal diversity at some selected habitats around the Negombo estuary in Sri Lanka in relation to land-use modifications. During the study period, we observed 48 bird species of which 47 species are residents to Sri Lanka. The avian species richness, evenness, and heterogeneity were found to be the highest at undisturbed habitats. Further, these diversity measures were negatively correlated with the intensity of anthropogenic land-use activities. Total abundance of birds increased at highly disturbed habitats due to the presence of the house crow, as it is the most abundant of all birds observed at these habitats. This study highlights the need for habitat management around estuaries, giving due consideration to existing ecological theories to conserve avifaunal diversity. It also highlights the negative impacts of the house crow on diversity of other resident avian fauna in these habitats.