Wintering Ornithofaunal Species Diversity and Abundance of an urban Freshwater Lake, West Bengal, India

Abstract

An ornithological survey was carried out for three consecutive years 2015 - 2017 for assessing the habitat status; diversity, feeding behaviour and distribution of avifauna during winter months in and around Lake Saheb Bandh. Attempts were made to cover the representative areas, in order to cover migratory, residential and residential migratory species, highlighting the current status and diversity of ornithofauna. The lake was threatened due to demographic pressures and it is over- exploited. A total of 89 species of birds belonging to 35 families and 14 orders were recorded from the study area. Anatidae (RDi= 14.607) and Ardeidae (RDi= 7.865) were the dominant families with highest relative diversity. Among the recorded avifauna, 51 species were resident, 24 species were migratory and 14 species were residential migratory. In this urban area, the species richness of feeding guilds varied significantly. Most birds were omnivorous (46.07%), followed by insectivorous (21.35%), carnivorous (20.22%), granivorous and frugivorous (5.62%), and nectarivorous species (1.12%). Maximum species richness was recorded in wintering months. Ferruginous Duck Aythya nyroca and Alexandrine Parakeet Psittacula eupatria are near threatened species and have a protected status under the schedule IV of Indian Wildlife Protection Act, 1972. Interestingly, 23 species having a globally declining trend are still very common in the study area. According to IUCN Red List version 3.1.7, 87 species were Least Concern (LC), 2 species were near threatened (NT). Different diversity indices were also calculated. Saheb Bandh Lake supports a huge amount of bird diversity. Shannon's diversity index indicate higher species diversity (H’ = 3.863). So continuous monitoring of avian fauna and health condition of the ecosystem by local or state levels on taking integrated management programs will helpful to maintain a sustainable development of the habitat.  The present study location is also facing tremendous conservation challenges by the impact of anthropogenic alteration of the habitats in and around the lake. Long-term studies are required to monitor any change in the avian communities of this urban landscape resulting from urbanization.