The mighty river Koshi calm in winter swells up largely in monsoon brining severe flood problems and often changes its course. The depth of the river fluctuates largely from season to season. Riverine forests dominate the vegetation of the reserve. Sal forest and grassland are also found to the west of the Koshi River. This diverse habitat of different vegetation type and wetland and scrub side makes the faunal wealth of this place incomparable to other protected area system of Nepal of which birds dominate the scenery.

Kosi Tapu is Nepal’s finest wetland and simply one of the best spots in all Asia for birds. Almost all of the country’s long list of wetland birds occur here, including Black-necked and Lesser Adjutant Storks, Black and Black-headed Ibises, Spot-billed and Falcated Ducks, Baer’s Pochard, the stunning Pied Harrier, Red-necked Falcon, Ruddy-breasted Crake and the rare Swamp Francolin. Handsome Black-bellied and River Terns fish the wide waters of the river, while the tree-lined bunds and swamps, choked with reed and water hyacinth, are full of exciting passerines like Verditer Flycatcher, Thick-billed, Dusky and Smoky Warblers, and the king-size Striated Grassbird.

In fact, it’s nothing unusual to see well over 100 species each day, as we explore the marshes on foot, inaccessible sandbanks and islands by rubber-raft, and the more remote corners of the reserve by 4-wheel drive vehicle. Large mammals of note include wild Water Buffalo (one of the world’s most endangered large mammals), Golden Jackal, Jungle Cat and Nilgai; we might even spot the rare Ganges River Dolphin on our voyage downstream. As a prelude to all this, we may be woken in the morning by the maniacal cries of the Common Hawk Cuckoo.

Arna of wild Buffalo (Bubalus bubalis), Blue Bull (Bocelaphus tragocamelus) and Gangetic Dolphin (Platanista gangetic) are the main attraction of this reserve. The lesser mammalian species include varieties of deer, cats, otters, bats, boar etc.

Around 300 species of birds have been recorded in the reserve area that mostly includes waterfowls, birds of prey, waders and other water birds.

Globally threatened “Swamp partridge” (Francolinus gularis) becomes a familiar bird frequently coming on every day list here. Koshi barrage although not inside but close and south of the reserve has created a vast expanse of water – making this place by far the most important staging point for migrating birds and an all – the – year – round playground for residents. Lesser known reptiles, amphibians, fishes and arthropods are worth exploring here.

Besides these wealth of flora and fauna, natural scenery for sunrise add more life to a nature – lover while being at Koshi. On a clear day a glimpse of Makalu (8463 meters) the world’s fifth mountain, enhances the beauty of the area in an inexplicable way.

Tentative Program of Koshi Tappu Wildlife