Sri Lanka is home to 439 species of birds of which 236 are resident, 203 migrant and the rest vagrant species. Migratory birds, both terrestrial and aquatic, arrive from Siberia, Scandinavia and Western Europe around September-October and stay antil April. See the spectacular Indian Pitta, Pied Thrush, Kashmir Flycatcher or Orange-headed Thrush. But if you are not that interested in migratory birds, you can see some awesome endemic birds until July!
The main bird watching site is Kumana National Park, an essential nesting and breeding sanctuary in Sri Lanka. The Bundala national Park situated on the migratory routes is great to watch flamingos, storks and herons. Also, visit Kalametiya Bird Sanctuary, Bodinagala Forest Reserve, Peak Wilderness Sanctuary, Kitulgala Forest Reserve, and Yala National park.