The National Chambal Sanctuary (NCS) exhibits a wide diversity in faunal composition. The major fauna of the sanctuary can be classified into two groups: i) aquatic and; ii) terrestrial. The NCS provides shelter to 25 species of aquatic and terrestrial mammals, 135 species of birds of which 76 species are wetland birds, 13 species of reptiles of which 9 are wetland species (list in Appendix -I); and several species of amphibians and fish (WII unpublished report 1990). Of the total species reported from Chambal valley, 31 species are listed in the Schedule 1 of the Indian Wildlife (Protection) Act, 1972. The checklist of major fauna of the sanctuary has been given in the Appendix -I.

Apart from this, the sanctuary harbours world's largest population of gharial and acts as a last refuge for it. Atleast 2000 captive reared gharials have already been released into the sanctuary which had an initial population of approximately 10,000 gnarlals. In IS sanctuary now has 100 adults, of which 13-14 are male, 60 breeding female and rest are non breeding males and females expected to breed shortly. These 100 adult individuals form the breeding nucleus in the sanctuary (Hussain and Choudhary 1992).