One hundred and six bird species belonging to 42 families under 66 genera were recorded during the study period. There was no significant difference (P>0.05) in the Shannon and Fisher’s alpha diversities, species evenness and richness of bird communities among different seasons in the BUC region. Although number of bird species recorded during the summer, monsoon and winter seasons slightly varied, it was not significantly different (P>0.05). Among the recorded bird species, Psittacula krameri showed the highest relative abundance (6.96%), whereas it was 0.04% in the case of Coracias benghalensis. Similarly, Psittacula krameri showed the highest species distribution ratio (0.070), whereas it was 0.002 in the case of Coracias benghalensis. Of the 42 families, Sturnidae was the highly abundant and dominant family. Also, Acciptridae was the richest family. Insectivore birds are found in highest number among other types. Similarly, the highest number of birds was residents. All recorded birds were of least concern.
Thirty two species of flowering plants/ trees belonging to 29 genera under 14 families present in the campus were mainly useful for perching. Additionally 28 species of flowering plants/ trees belonging to 23 genera under16 families were recorded in the campus were mainly depend on birds for pollination and/or seed dispersal. Nesting of 16 bird species were recorded in the BUC region. Among them, 6 species of birds was successful in the breeding and parental care of their young ones. Most of the bird species were found feeding on the nectar of Lantana camara, Mangifera indica, Muntingia calabura, and Spathodea campanulata flowers. Similarly, the majority of the bird species were found feeding on the fruits of Ficus bengalensis, Ficus religiosa and Muntingia calabura. Interactions between the different bird species among kites (black and brahminy), crows (house and large-billed) and mynas (common and jungle) were observed in the present study for the food and shelter. Also, the eggs predation of the Spotted Dove and Red-whiskered Bulbul by unknown predator in their nest was observed. Interactions within the same species of above mentioned birds for the competition of food, habitat and mating were also observed.
Within the study region, variations in the number of family and species abundance, richness and percent frequency of bird species were observed in the BUC region. This factor also influences the number of bird species and bird diversity. Bird species respond to the several environmental factors along a gradient of urban mosaic complexity. The variations in the abundance of different species of avian communities are depending on the availability of food sources, vegetation, number of buildings, canopy coverage, tree density, number of nesting sites, and human population density, etc. The bird species richness increases with structural complexity of the habitats landscape diversity. This suggests that the primary requirements such as food, shelter, resting, roosting and nesting sites for bird communities are not equally available in the different seasons within the study site. Moreover, several qualitative landscape features, particularly the type and level of human disturbance and the presence of fruiting, and flowering trees also influence avian community composition. The campus premises suffer from several threats such as habitat alteration, grass cutting, fire, and livestock grazing. Several conservation measures, including habitat management strategies such as restoration of riparian vegetation, wetlands, and check dams, increasing plant and tree diversity are recommended to protect the campus environment and to conserve its avifaunal diversity.