The present study was carried out in the recently established Warathenna-Hakkinda EPA in the Kandy District, Sri Lanka to investigate the avifaunal diversity and conservation threats. Sampling was conducted in two main habitat types: river islands and riverine forests. Both point count (10 m radius) and line transect (200 m long) methods were utilized and maximum of 30 minutes was used to sample the birds in each point. Food habit, niche type, endemism, abundance, and diversity indices (Shannon & Margalef) were calculated to compare the two habitats in this area. A total of 74 bird species belonging to 61 genera and 35 families were encountered from the study site. Among these, seven species are endemic: Sri Lanka Grey Hornbill, Sri Lanka Green Pigeon, Sri Lanka Wood Pigeon, Sri Lanka Hanging Parrot, Crimson-fronted Barbet, Yellow-fronted Barbet, and Sri Lanka Hill Mynah; while six were migratory: Green Sandpiper, Common Sandpiper, Indian Pitta, Asian Brown Flycatcher, Yellow Wagtail, and Grey Wagtail and the rest were non-endemic natives. Most of them were canopy and sub canopy dwellers associated with riverine forests and islands. According to the National Red List of Sri Lanka, three species, the Sri Lanka Wood Pigeon, Sri Lanka Hill Mynah, and Alpine Swift, are listed as threatened. Ardeidae, Alcedinidae, Columbidae, Accipitridae, and Apodidae were the most species rich families in this habitat. Out of the sampled species, 31% and 25% of the birds were carnivores and insectivores, respectively, while 5% were nectarivores. According to the avifauna, the riverine forests are more diverse (Shannon index H’= 2.55; Margalef’s index M= 10.92) than the river islands (H’= 2.29; M= 5.07) in this landscape. The variety of habitats along the Mahaweli River at Warathenna appears to aid in sustaining a rich bird community and this Environmental Protection Area will help create a safe haven for the birds.