The gateway to Kumana National Park is at Panama. The park office is located at Okanda, 22km south of Panama.
Kumuna receives 1,300 millimetres (51.18 in) of annual rainfall. The mean annual temperature is 27 degrees Celsius.
Kumana National Park spreads over an area of 35,664 hectares. In the west, the park is bordered by River Kumubukkan Oya; to the south is south-eastern coast that runs to Panama. A 200 hectares mangrove swamp called “Kumana Villu” within the Park is subject to occasional inundation with sea water. It is at this swamp that many water birds nest, during the months of May and June. Scattered in the Kumana National Park are several water pools that are favorite spots of the wildlife: Kudawila wewa, Thummulla wewa and Kotalinda wewa.
Kumana National Park provides excellent feeding and resting habitats for a large number of threatened wetland species, including three turtle species such as the Green Turtle (Chelonia mydas), Loggerhead Turtle (Caretta caretta), and the Olive Ridley Turtle (Lepidochelys olivaceae).
Among other threatened species of reptiles are the globally vulnerable Mugger Crocodile (Crocodylus palustris).The most sighted reptiles at Kumana National Park are Mugger Crocodile, the Indian Flap-shelled Turtle, and the Indian Black Turtle.
Sri Lanka records more than 430 bird species comprising endemic, resident and migrant birds. Of these, the bird watchers are able to watch over 200 species easily. The wide variety of birds found in the numerous wildlife parks of Sri Lanka makes the tropical island a prime bird watching destination in the world. The Kumana National Park is the most important and most popular bird sanctuary in Sri Lanka. Kumana birdlife supported by Some 20 lagoons and tank is an ornithologist’s paradise. During April–July, tens of thousands of birds migrate to the Kumana swamp area annually nearly 255 species of birds have been recorded in the National Park. Regular sightings of birds include pelicans, painted storks, spoonbills, white ibis, herons, egrets and hundreds of little cormorants. The very rare black-necked stork has also been spotted at the swamp.
Among the breeding inhabitants of the Kumana villu are the rare species such as Black-necked Stork, Lesser Adjutant, Eurasian Spoonbill, and Great Thick-knee are breeding inhabitants of the Kumana villu.
The bird species migrate here in large flocks. Asian Open bill, White-breasted Water hen, Lesser Whistling Glossy Ibis, Purple Heron, Great Egret, Indian Pond Heron, Weathercock, Purple Swamp hen, Duck Black-crowned Night Heron, Intermediate Egret, Little Egret, Spot-billed Pelican, Indian Cormorant, Little Cormorant, Common Moorhen, and Little Grebe are the bird species migrate here in large flocks.
Among the rare birds that migrate to the swamp include Yellow-footed Green Pigeon, Greater Racket-tailed Drongo, Malabar Trogon, Red-faced Malkoha, and Sirkeer Malkoha. Pacific Golden Plover, Greater Sand Plover, Lesser Sand Plover, Grey Plover, Ruddy Turnstone, Little Ringed Plover, Wood Sandpiper, Marsh Sandpiper, Common Redshank, Common Sandpiper, Curlew Sandpiper, Little Stint, Common Snipe, and Pintail Snipe are the common wading birds at the Park.
Apart from being abound with the birdlife, Kumana is also home to some of the mammals found in the adjacent Yala National Park such as Elephants, Leopards, Golden Jackal, Wild Boar, European Otter as well as the endangered Fishing Cat.
Coastal wetlands of Kumana have its inhabitants engaged in lagoon fishing and rice cultivation.
The bird population has taken a dip at Kumana National Park in recent years. Environmentalists and wildlife enthusiasts have expressed their concern over a road planned to be constructed from Kirinda to Panama which will run along the coastline of the park disturbing the habitat of the birdlife.