Koshi Tappu Wildlife Reserve

Below the Koshi's exit from the hills, the river spreads into a maze of channels, sandbanks and tall grass islands. This is Koshi Tappu — 'tappu' meaning island — one of the most important wetlands in South Asia.

The arna

The reserve was created in 1976 to save the wild water buffalo, or arna, whose last Nepali population survived here. Arna are larger and wilder than village buffalo, with huge sweeping horns. Their numbers have recovered, and seeing a herd in the grass at dawn is the reserve's signature sight.

A birder's reserve

Koshi Tappu is Nepal's best-known birding site. In winter the river fills with ducks, geese and waders migrating from Central Asia and Siberia; resident specialities include the swamp francolin, and the grasslands hold rare species such as the Bengal florican. Gangetic dolphins have been recorded in the river, and golden jackals, wild boar and many reptiles live in the reserve.

How to visit

Exploring is done on foot with guides along the embankment, by jeep, or by boat on the river. A handful of lodges and camps near the reserve arrange birding walks and rafting. Take binoculars, dress in muted colours and start early.

The river's power

The Koshi carries enormous amounts of silt and has shifted its course many times, earning it the name 'sorrow of Bihar'. In August 2008 it broke its eastern embankment at Kusaha and flooded villages on both sides of the border — a reminder that this landscape is always changing.