At 176 sq. km, Koshi Tappu is smaller than other wildlife reserves in Nepal, but has a reputation for being one of the world’s best bird watching locations. The recognised wetland is a habitat for an estimated 439 species of bird. Many of these are aquatic varieties such as ducks, herons, storks, egrets and ibis. During the winter its resident population of birds is joined by migratory species which fly in from Siberia.

Gharial crocodile and freshwater dolphins are population attractions in the area. Koshi also has patches of scrub and deciduous forest where buffalos, boars, hogs, deer and jackal can be seen