Wilpattu is among the top national parks world-renowned for its leopard population. A sample of forty-nine individual leopards were photo-captured in the surveyed area and the core area density was between that of Yala National Park’s Block I and Horton Plains National Park. There are many types of vegetation to be found in Wilpattu, including littoral vegetation, such as salt grass and low scrub monsoon forest with tall emergents, such as palu (Manilkara hexandra), and satin (Chloroxylon swietenia), milla (Vitex altissima), weera (Drypetes sepiaria), ebony (Diospyros ebenum) and wewarna (Alseodaphne semecapriflolia).
31 species of mammals have been identified within Wilpattu national park. Mammals that are identified as threatened species living within the Wilpattu National Park are the elephant, sloth bear, leopard and water buffalo. Sambhur, spotted deer, mongoose, mouse and shrew are more of Wilpattu’s residents.
The painted stork, the open bill, little cormorant, Sri Lankan junglefowl (Gallus lafayetii) along with many species of owls, terns, gulls, eagles, kites buzzards are to be found at Wilpattu National Park. Wetland bird species that can be seen in Wilpattu are the garganey, pintail, whistling teal, spoonbill, white ibis, large white egret, cattle egret and purple heron.
The most common reptiles found in the park are the monitor lizard, mugger crocodile, common cobra, rat snake, Indian python, pond turtle and the soft-shelled turtle which are resident in the large permanent Villus.