Koshi Tappu Wildlife Reserve can claim its distinct identity for one good reason – the vast expanse of the Koshi River. Today, with the wild buffalo preserved, the reserve has also won its niche as birdwatcher's paradise in its true sense. The reserve to preserve the habitat of the remaining population of wild buffalo (locally known as Arna in Nepali). The reserve beckons all sorts of bird species. These birds fly all the way from Siberia to migrate during the winter season. The fact that many birds that arrive here are nowhere else seen in Nepal. Koshi Tappu Wildlife Reserve is a homeland of endangered Gharial crocodile, Gangetic dolphin, ducks, herons, storks, egrets, and ibis and among others.