The KTWR is biologically diversified as it consists of 21 species of invertebrates, 77 species of butterfly, 127 species of fish, 45 species of herpetofauna, 526 species of bird and 31 species of mammals. Similarly, floral diversity scores high position as flowering plants recorded 502 species, medicinal plants 18 species, fodder 33 species, edible plants 22 species and fern 12 species (Management Plan of KTWR and its Buffer Zone, 2018).
The Reserve and its associated wetlands were designated as a Ramsar Site in 1987. Altogether Nepal’s 10 wetlands of international importance are listed in Ramsar Sites so far. Out of which the Koshitappu Wildlife Reserve is the first one.