Kawar (Kabar) Lake Wildlife Sanctuary, also a Ramsar Site, is the largest freshwater lake in northern Bihar. It is a residual oxbow lake formed by the changing course of the River Gandak, a tributary of the Ganga.The lake is eutrophic, sustaining rich plant and animal life, and teeming with waterfowl (George 1964). Kawar is one of the most important wetlands for waterfowl in the Indo-Gangetic Plain. It supports huge numbers of migratory ducks and Coot Fulica atra through the winter, as well as large concentrations of resident species such as Dabchick Tachybaptus ruficollis and Asian Openbill Anastomus oscitans.
The Kanwar Taal or Kabar Taal Lake located in Begusarai district of Bihar, India, is Asia's largest freshwater oxbow lake. It is approximately three times the size of the Bharatpur Sanctuary. Ornithologist Salim Ali, mentioned about 60 migratory birds that come all the way from Central Asia in winter and recorded around 106 species of resident birds.