Abstract:
Bundala National Park, covering an area of 6216 ha, is located about 250 Km Southeast
of Colombo, in the Hambantota District. The shallow brackish water lagoons located within the park -
Koholankala (390 ha), Malala (650 ha), Embilikala (430 ha) and Bundala (520 ha) form a complex
wetland system that harbors a rich bird life, including several species of migratory waterfowl. This led
to the declaration of Bundala as Sri Lanka's first Ramsar wetland - a wetland of international
importance especially for migratory waterfowl, in 1990. Distribution and the composition of the
aquatic bird species inhabiting these lagoons with respect to the habitat characters are poorly
understood. Present study was conducted (December, 2000-December, 2001) in Malala, Embillakala
and Bundala Lewaya lagoons with the objective of investigating the relationship between some lagoon
parameters (salinity, perimeter, area) and water bird abundance and diversity. Data were collected
weekly basis. Bird abundance and the composition significantly differ among lagoons. This study
revealed the most abundant bird groups in each lagoon. Highest aquatic bird diversity was recorded in
Embillakala. This high diversity in Embillakala lagoon can be partly attributed to its moderate salinity,
water depth and abundance of aquatic macrophytes. Lowest aquatic bird diversity was recorded in
Bundala Lewaya. This study also revealed that salinity, aquatic macrophytes and lagoon area were key
determinants of aquatic bird abundance. Although these lagoons are in the same landscape, they vary
each other physically and chemically so that different bird communities might be supported.
