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 was a substantial cause of Congress instituting the ban and many non-DDT oriented actions were taken on their behalf under the Endangered Species Act (i.e. captive breeding, habitat protection, and protection from disturbance). As of October 28, 2012, there are 2,052 total (foreign and domestic) species on the threatened and endangered lists. However, many species have become extinct while on the candidate list or otherwise under consideration for listing. Species which increased in population size since being placed on the endangered list include: Opponents of the Endangered Species Act argue that with over 2,000 endangered species listed, and only 28