Koshi Tappu: A Birdwatcher's Guide to Nepal's Great Wetland

Nepal is better known for mountains than marshes, yet one of its finest wildlife sites is almost perfectly flat. Koshi Tappu Wildlife Reserve lies on the floodplain of the Sapta Koshi, the largest river system in the country, close to the Indian border in the eastern Terai. For birdwatchers it is the single most productive location in Nepal.

The setting

The Koshi drains a huge section of the eastern Himalaya, including the Everest region, and spreads out on reaching the plains into a braided maze of channels, sandbanks, reed beds, oxbow lakes and wet grassland. A barrage near the border regulates the flow and has created wide areas of open water upstream.

The reserve protects a strip of this floodplain. It was Nepal's first wetland to be listed as internationally important under the Ramsar Convention.

The birds

Close to five hundred species have been recorded, a remarkable figure for a small area. What you see depends on the season.

Winter (November to February) brings tens of thousands of ducks, geese and waders from Central Asia and Siberia. Rafts of pochard, pintail, gadwall and teal cover the open water, with bar-headed geese and ruddy shelduck on the sandbanks.

Residents and specialities include the swamp francolin, the Bengal florican (rare and hard to find), several species of stork including the lesser adjutant, striated grassbird, a range of warblers and bush chats in the grassland, and numerous birds of prey. Vultures and fishing eagles are regularly seen.

Spring and autumn passage adds migrating raptors, swallows and smaller birds moving along the foot of the mountains.

A keen birder with a good guide can log well over a hundred species in two days in winter.

Other wildlife

Koshi Tappu holds Nepal's only remaining population of wild water buffalo, known locally as arna. The bulls are massive, with wide sweeping horns, and are usually seen grazing in herds on the river islands. The reserve also has spotted deer, hog deer, wild boar, blue bull antelope, jackals, fishing cats, pythons and mugger crocodiles. Ganges river dolphins are occasionally seen in the main channel near the barrage.

How to explore

• On foot along the eastern embankment, a raised earth bank that runs for many kilometres and gives a clear view over marsh on one side and farmland on the other. This is where most birding is done.

• By boat, drifting down a river channel in an inflatable raft or wooden boat for close views of waterfowl, buffalo and crocodiles.

• By jeep along tracks to more distant grasslands and lookout towers.

Dawn and late afternoon are the active hours. Midday is for rest.

Where to stay

A handful of tented camps and lodges sit just outside the reserve boundary on the eastern side, several of them set up specifically for birdwatchers with resident naturalists, checklists and telescopes. Accommodation is comfortable but simple, and stays are usually sold as packages including meals, guiding and activities. There are also basic guesthouses and homestays in nearby villages.

Getting there

Fly from Kathmandu to Biratnagar, about forty minutes, then drive one and a half to two hours to the camps. Lodges arrange pickups. By road, the East-West Highway passes close to the reserve; buses from Kathmandu take around ten to twelve hours.

When to go

Peak season is December to February for sheer numbers of waterbirds. October, November and March are also very good, with pleasant temperatures. From April the heat builds, and during the monsoon the river floods widely and access is limited.

Morning fog is common in midwinter and can delay both flights to Biratnagar and the start of birding, so build some slack into your plans.

What to bring

Binoculars are essential, and a telescope is useful if you have one, though camps often provide them. Pack a field guide to the birds of Nepal or the Indian subcontinent, neutral-coloured clothing, a warm layer for cold boat rides at dawn, sun protection and insect repellent.

Fitting it into a trip

Koshi Tappu works well as a two- or three-night visit combined with other parts of eastern Nepal: the tea gardens of Ilam in the hills to the north-east, or the temple city of Janakpur to the west along the highway.

It is a specialised destination, and visitors who are not interested in birds may find it too quiet. For those who are, sitting on the embankment at sunrise as skeins of geese come in over the mist is one of the great wildlife experiences in South Asia.