Wetlands serve as critical habitats for avifauna, providing essential resources for feeding, breeding, and migration. Understanding the density patterns of bird populations is vital for ecological monitoring and conservation planning. This study aimed to assess the density variations of avifauna in three major wetlands of North Karnataka, India, namely Supa Reservoir, Ghataprabha Bird Sanctuary, and Hirehalli Tank, over a six-month period from October 2024 to March 2025. Standardized point count and transect methods were employed to survey bird populations, with observations recorded during morning and evening sessions to capture temporal variations in activity. Species richness, abundance, and density per hectare were calculated and analyzed to compare inter-site differences.

A total of 125 bird species were recorded across the three wetlands, representing 42 families and 11 orders. Supa Reservoir exhibited the highest species density, averaging 42.6 individuals per hectare, followed by Ghataprabha Bird Sanctuary (38.1 individuals per hectare) and Hirehalli Tank (29.4 individuals per hectare). Seasonal fluctuations were evident, with peak densities observed during the post-monsoon months of November and December, coinciding with migratory influx. Waterfowl and waders dominated Supa Reservoir, while Ghataprabha showed greater representation of resident passerines. Habitat heterogeneity, water quality, and vegetation cover appeared to be the primary drivers of observed density variations. Statistical analyses revealed significant differences in avian density among the three wetlands, emphasizing the influence of site-specific ecological characteristics.