Ganges Delta trees are found in these areas. The delta region has mangrove trees. It is estimated that 30,000 chital ("Axis axis") are in the Sundarbans part of the delta. Birds found in the delta include kingfishers, eagles, woodpeckers, the shalik ("Acridotheres tristis"), the swamp francolin ("Francolinus gularis"), and the doel ("Copsychus saularis"). Two species of dolphin can be found in the delta: the Irrawaddy dolphin ("Orcaella brevirostris") and the Ganges river dolphin ("Platanista gangetica gangetica"). The Irrawaddy dolphin is an oceanic dolphin which enters the delta from the Bay of Bengal. The Ganges river dolphin is a true river dolphin, but
Endangered Species Act of 1973 occurred by 1963 to habitat preservation instead of take regulations. A provision was added by Congress in the Land and Water Conservation Fund Act of 1965 that provided money for the "acquisition of land, waters...for the preservation of species of fish and wildlife that are threatened with extinction." The predecessor of the ESA was the Endangered Species Preservation Act of 1966 (P.L. 89-669 ). Passed by Congress, this act permitted the listing of native U.S. animal species as endangered and for limited protections upon those animals. It authorized the Secretary of the Interior to list endangered domestic fish and wildlife