A day on the Karnali for dolphins and gharials

The Karnali rises in Tibet and cuts through western Nepal before emerging from the Siwalik hills at Chisapani, close to the north-west corner of Bardia. Below the gorge it spreads into wide channels, sandbanks and islands, forming the park's western boundary. A river day starts with a drive to Chisapani, where the steep hills drop to the water, and continues by inflatable raft downstream with an experienced river guide and our naturalist. Life jackets are worn throughout, and the water here is gentle.

The Gangetic dolphin, or river dolphin, is almost blind and finds its prey by sound. Only a small number live in the Karnali, so sightings are never certain, but pools near Chisapani and the confluences are among the places where they are seen surfacing to breathe. On the banks look for mugger crocodiles, the rarer gharial, smooth-coated otters, and birds such as ibisbill, river lapwings, terns, kingfishers and ospreys. Wild elephants sometimes cross the channels.

We stop for lunch on a sandbank or under a tree, and continue drifting through the afternoon before the lodge vehicle meets us downstream. It is a long but relaxed day, ideal after early mornings tracking tigers. In the hottest months we keep it shorter. Bring a hat, sun cream, sunglasses, a change of clothes and binoculars. River conditions, rafting routes and rules on boats in the park vary with season and water level, so check current status before you travel.