<p>Assessment of avian diversity is essential for understanding ecosystem health and guiding conservation planning, particularly in some lesser-known protected landscapes where baseline biodiversity information is lacking. The newly declared Gupteswar Forest Biodiversity Heritage Site represents a biologically important yet poorly documented ecosystem in the Eastern Ghats region. Prior to this study, no systematic investigation of avifaunal diversity had been conducted in this landscape. Therefore, the present study aimed to establish a baseline inventory and evaluate species richness, seasonal variation, diversity indices, foraging guild structure of birds in the area. Field surveys were conducted from September 2021 to September 2022 using standardized point count and line transect methods both in morning as well as evening during each season comprising three consecutive days. Sampling was carried out within an area of 30&#xa0;ha comprising three sampling plots. The study area comprises a heterogeneous ecological mosaic of moist deciduous forest, riparian habitats associated with the perennial Sabari River, agricultural fields, grasslands, and scrublands. A total of 158 bird species belonging to 18 orders, 54 families, and 114 genera were recorded during the survey period. Seven feeding guilds were identified, with insectivores dominating the assemblage (60.12%), indicating the ecological importance of the forest. Based on global population trends, the assemblage included 52 stable species, 66 decreasing species, 18 increasing species, and 22 species with unknown trends. Shannon–Wiener diversity index suggests relatively stable avian diversity within the landscape, supported by structurally diverse vegetation, fruit-bearing trees, and riparian habitats. This study provides the first systematic documentation of avifauna from the Gupteswar BHS and establishes a baseline for long-term monitoring, ecological assessment, and conservation planning in this biodiversity-rich landscape of the Eastern Ghats.</p>