Wildlife · Nepal
Wild Water Buffalo (Arna) in Nepal
Asia's largest wild bovid, the arna survives in Nepal almost only in the Koshi Tappu wetlands — where to find it and why it is endangered.
The wild water buffalo (Bubalus arnee), known locally as the arna, is the largest wild bovid in Asia and one of Nepal's rarest large mammals. A massive, marsh-loving giant with huge sweeping horns, its last wild stronghold in the country is a single reserve in the eastern Terai wetlands.
Description
The arna is a heavily built bovid, far bigger than its domestic descendant, with a slate-grey to blackish coat and the widest horns of any living cattle — long, low and sweeping outward in a great crescent. Bulls are especially massive and powerfully muscled. It is the wild ancestor of the domestic water buffalo, but should never be confused with that animal or with the unrelated African buffalo.
Where to see it in Nepal
Nepal's last wild population survives almost entirely in the Koshi Tappu Wildlife Reserve, on the floodplain of the Sapta Koshi river. The reserve's wet grasslands and marshes are the only reliable place to find the arna in Nepal, and the surrounding wetland is also one of the country's premier spots for birdwatching.
Conservation status
The wild water buffalo is listed as Endangered on the IUCN Red List and is fully protected under Nepali law. Its global range has collapsed, and Koshi Tappu now holds one of the few viable herds left in South Asia — making it a flagship of Nepal's endangered wildlife.
Best parks and season
Plan your visit for the cool, dry October to April season, when receding floodwaters expose the grasslands and animals are easier to scan across the open floodplain. Early-morning and late-afternoon outings by jeep or boat give the best light and the best chances of a herd by the water's edge.
Behaviour and ecology
The arna is a grazer of wet grasslands and marshes, spending much of the day feeding on grasses and sedges and wallowing in mud and shallow water to keep cool and shed parasites. It lives in herds led by females, while older bulls may be solitary, and it is rarely far from water. As a large grazer it helps shape the floodplain's mosaic of grass and reed, habitat that in turn supports deer, wetland birds and other Terai species.
Safari notes
This is a powerful wild animal, and lone bulls can be unpredictable, so keep a respectful distance and follow your guide's lead at all times. Use the reserve's boats and vantage points to scan the marshes, bring binoculars for the open grasslands, and resist the urge to approach a herd on foot.
The arna shares Nepal's Terai with grassland giants like the one-horned rhino and a wealth of wetland birds. Explore the full wildlife of Nepal collection and the national parks of Nepal.
Frequently asked questions
Where can you see wild water buffalo in Nepal?+
Nepal's last wild population survives almost entirely in the Koshi Tappu Wildlife Reserve in the eastern Terai. The reserve's wet grasslands and marshes along the Sapta Koshi river are the only reliable place to see the arna in the country.
What is the conservation status of the wild water buffalo?+
The wild water buffalo is listed as Endangered on the IUCN Red List and is fully protected in Nepal. Its global range has shrunk dramatically, and Koshi Tappu holds one of the few remaining viable herds in South Asia.
What is the difference between an arna and a domestic buffalo?+
The arna is the wild ancestor of the domestic water buffalo but is far larger, with a heavier build and enormous sweeping horns. It is the biggest wild bovid in Asia. It should not be confused with the domestic buffalo or the African buffalo.
Why is the wild water buffalo endangered in Nepal?+
The main threats are hybridisation and disease passed from domestic buffalo, habitat loss, and flooding of the Sapta Koshi that washes through its grassland home. Interbreeding with domestic stock dilutes the pure wild gene pool.
When is the best time to see the arna at Koshi Tappu?+
The cool, dry season from October to April is best, when water levels drop and grasslands are easier to scan. Early-morning and late-afternoon outings on the floodplain offer the best chances of a sighting.
