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 and allowed the United States Fish and Wildlife Service to spend up to $15 million per year to buy habitats for listed species. It also directed federal land agencies to preserve habitat on their lands. The Act also consolidated and even expanded authority for the Secretary of the Interior to manage and administer the National Wildlife Refuge System. Other public agencies were encouraged, but not required, to protect species. The act did not address the commerce in endangered species and parts. In March, 1967 the first list of endangered species was issued under the act. It included 14 mammals, 36