The Koshi Tappu Wildlife Reserve is situated in the flood plains of the Saptkoshi River in the eastern Terai. It covers an area of comprising grasslands and khair–sissoo riverine forests. It was established in 1976 and was declared a Ramsar site in 1987. The reserve provides habitat for hog deer, spotted deer, wild boar, blue bull, gaur, smooth-coated otter, jackal, 485 bird species including 114 water bird species, 200 fish species, 24 reptile and 11 amphibian species. The last surviving population of wild water buffalo in Nepal is found in the reserve, as well as Gangetic dolphin, swamp francolin and rufous-vented prinia. A small population of the critically endangered Bengal florican is present along the Koshi River. There are also records of white-throated bush chat and Finn's weaver. The bristled grassbird breeds in the reserve. The reserve together with the Koshi Barrage was identified as one of 27 Important Bird Areas of Nepal.