Bundala National Park is an important wintering area for migratory water birds in Sri Lanka. The park is an important bird sanctuary with prominent South Indian and Sri Lankan wetlands. There are 324 species of vertebrates in the national park, including 32 species of fish, 50 species of amphibians, 48 species of reptiles, 197 species of birds, and 32 species of vertebrates. Fifty-two species of butterflies are among the invertebrates. The wetland habitats in Bundala harbor about one hundred species of water birds, half of them being migrant birds. Of one hundred ninety-seven avifaunal species, 58 are migratory species. Amongst the immigratory birds are the Forest Wagtail, the Lesser Sand Plover, Brown Flycatcher, Sandpipers, Barn Swallow, Water Fowl, Common Redshank, Flock of Flamingos, and Petite Blue Tailed bee-eaters. They launched the National Bird Ringing Programme (NBRP) in Bundala in collaboration with the Department of Wildlife Conservation and Field Ornithology team of Sri Lanka in 2005. Giant Squirrel, Deer, Sloth Bear, Civets, Mongoose, Monkeys, and Leopard. The lagoons and marshes of the park hold both marsh & estuarine Crocodiles. In contrast, the coastal stretch of the park is a sanctuary for 05 species of marine turtle, namely loggerhead, green, leatherback, and olive ridley, who visit the beach to breed and lay eggs. The highlight is the greater flamingo, which migrates in large flocks.
In 1991 it became the first wetland to be expressed as a Ramsar site in Sri Lanka. It is a haven for many aquatic birds such as the migratory Greater flamingo, Stilts, Painted storks, Cormorants, Gulls, and Ducks, and the resident water birds such as Pelicans, Herons, Egrets, terns, Ibis, and Storks. In 2005 the preserve was designated as a biosphere reserve by UNESCO,
It is the fourth biosphere sanctuary in Sri Lanka. The national park is 245 kilometers (152 mi) southeast of Colombo.
The area was declared a wildlife preserve on 5 December 1969. It was enhanced to a national park on 4 January 1993. However, the park was gazetted in 2004, reducing the original garden to 3,698 hectares. Close to Hambantota, The Bundala National Park is considered an essential birding destination in Sri Lanka. For those traveling from Colombo, the route is via Galle, Matara, and Hambantota and from Kandy via Badulla. The climate at Bundala is primarily hot and dry, with average temperatures of 27 degrees Celsius from May to September, with plenty of migratory birds arriving between September and March.
The area of the park is 6,218 hectares and consists of a striking landscape made up of a mix of thorny scrublands, waterways, lagoons, marshes, and dunes, making it an inviting destination for thousands of migratory birds,
The reason for this fascination for Sri Lanka is its geographic location, just below the southern tip of the Indian subcontinent, making it the last destination in their long journey across the oceans.
As birders and nature lovers observe, these migratory birds stop in the same area yearly, and the birds will follow well-defined, conserved migration routes over long distances. This park’s bio-diversity is prolific, with 383 plant species recorded here, six endemic and seven endangered.
The annual temperature is 27 °C (81 °F). Annual rainfall ranges from 900–1,300 millimeters (35–51 in). The park’s elevation ranges from sea level to 10 meters. The park was affected by the 2004 Indian Ocean tsunami. Due to protection from dunes, the park received very little damage.
The water quality in the lagoons has changed by the drainage of excess water from irrigation systems—sludge released from the saltern into Bundala lagoon. The circulation of two invasive alien plants, Prosopis juliflora and Opuntia Dillenii, in the tidal flats and dunes of the Malala-Ambila Lagoons and the surrounding scrub, is threatening the habitats of migratory birds and wildlife in the scrub forests and dunes. The spread of Prosopis juliflora is made easy by uncontrolled livestock herds.
Proposed conservation measures include re-demarcation of the park’s boundary and expansion of the edge to include northern bushland, resettlement of park-dwelling families, a program to control the spread of invasive alien plants, and the creation of irrigation structures to stop irrigation runoff.