ABSTRACT - Diurnal species richness and diversity of aquatic avifauna at three reservoirs of the Anavilundawa Ramsar site of Northwestern Sri Lanka was recorded using line transact method from October 2009 to March 2010. Populations of the water birds were recorded from 7:00 hrs to 10:00 hrs, three times each month. Twenty eight species of water birds belonging to six orders and twelve families were recorded from Anavilundawa, Suruwila and Maiyawa reservoirs. These included two nationally threatened species, Spot-billed Pelican (Pelecanus philippensis) and Great Cormorant (Phalacrocorax carbo) and one winter visitor, Garganey (Anas querquedula). Relative abundance and rank correlation indicated that Lesser Whistling-Duck was the most common water bird species followed by the Purple Coot and Garganey. Common Moorhen was the least common bird followed by, Little Ringed Plover and Black Bittern. Birds belonging to Anatidae, Ardeidae, Phalacrocoracidae, Rallidae and Jacanidae families were recorded in high numbers. Among the families recorded, Anatidae family had the highest number of birds. Three waterfowl species belonging family Anatidae were recorded. They were, Lesser Whistling Duck (Dendrocygna javanica), Cotton Pygmy Goose (Nettapus coromandelianus) and migratory waterfowl Garganey (Anas querquedula). Suruwila reservoir had the highest Shannon diversity (H') index of 2.345 while Anavilundawa had the lowest diversity index of 2.104. Water birds diversity of the Anavilundawa reservoir differed significantly from the Maiyawa reservoir (t = 0.140, df = 2133). However it did not differ significantly from the Suruwila reservoir (t = 3.022, df = 3047). The diversity of water birds between Suruwila reservoir and Maiyawa reservoir did not differ significantly (t = 2.644, df = 1840). Evenness was high in the Maiyawa reservoir (0.747) and low in the Anavilundawa reservoir (0.638). Present study revealed that the three reservoirs of the Anavilundawa Ramsar wetland provide an important habitat for twenty eight water bird species, and thus warrant protection.

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Akbar, M., M.M.U. Hassan, Z.U. Nisa & M. Hassan (2009). Waterfowl diversity at Chashma barrage (wildlife sanctuary Mianwali) and Marala headworks (game reserve Sialkot) Pakistan during 1996–2005. Int. J. Agric. Biol. 11: 188–192.

Alfred J.R.B, A. Kumar, P.C. Tak & J.P. Sati (2001). Waterbirds of Nothern India. Rec.Z.S.I.India, Occ, Paper no. 190(1-xxiv):1-227.

Borges, S.D. & A.B. Shanbhag (2008). Food resource partitioning among water birds wintering on the Diwar wetlands in the Mandovi Estuary of Goa, India. Sengupta M. and Dalwani, R. (2007), Editors, proceedings of Taal; the 12th World lake conference, 124-130.

Custer, T.W. & R.G. Osborne (1977). Wading birds as biological indicators. Long Survey, US. Fish and Wildlife service, Washington, DC.

Daniel, H.J. (1983). Costa Rican Natural History. Pp 584-586.Gibbs, B (1993); Ornithology by Corinne Stockley, Felicity Brooks and: Felicity Brooks, Corinne Stockley.

Grimmett, R. & T. Inskipp (2007). Birds of Southern India. Om Books International, New Delhi, India.

Gunaratne, A.M., S. Jayakody & C.N.B. Bambaradeniya (2009). Spatial distribution of aquatic birds in

Anavilundawa Ramsar wetland sanctuary in Sri Lanka. J Biol. Invasions 11:951-958.

Harrison J. & T. Worfolk (1999). A Field Guide to Birds of Sri Lanka, Oxford University Press Inc, New York.

Mahaulpatha, W.A.D., W.M.T. Mahaulpatha & K.A.I. Wasantha (2008). Effect of Water-level and Invasive Plants on Pheasant-tailed Jacana (Hydrophasianus chirugus) at the Annaiwilundawa Ramsar Site of North-Western of Sri Lanka. Wetland Ecology Manage 16:33-42

Perera, M.S.J., W.P.N. Perera, R.K. Rodrigo, S.P. Ekanayake, C.N.B. Bambaradeniya,V.A.P. Samarawickrama & L.J.M. Wickramasinghe (2005). A Biodiversity Status Profile of

Annaiwilundawa Sanctuary – A Ramsar wet land in the Western Dry Zone of Sri Lanka, Occ. Pap 9, IUCN Sri Lanka.15

Turner, W.R. (2003), Citywide biological monitoring as a tool for ecology and conservation in urban landscapes: the case of the Tucson bird count. Landscape and Urban Planning 65:149-166.

Verner, J. (1999). Assessment of counting techniques. P 247-295. Forestry Science Laboratory Press. California.

Wijeyeratne, G. de S., D. Warakagoda & de T.S.U Zylva, (2008). A Photograhic Guide to Birds of Sri Lanka. New Holland Publishers (UK) Ltd.