Manas River tiger, elephant, gaur ("Bos gaurus"), four rare species of golden langur ("Trachypithecus geei"), pygmy hog ("Sus salvanius"), hispid hare ("Caprolagus hispidus"), greater one-horned rhinoceros ("Rhinoceros unicornis") and wild Asiatic water buffalo ("Bubalus arnee"). There are 362 species of birds, out of which four species of hornbills (rufous-necked, wreathed, pied and great Indian) have been recorded. Apart from the Ganges river dolphin ("Platanista gangetica") other aquan species identified in the river are the deep bodied mahseer ("Tor tor"), golden mahseer ("Tor putitora"), and chocolate mahseer or katle ("Acrossocheilus hexangonolepis"). Five thousand people live within the park limits in several villages. Tigers,
Endangered Species Act of 1973 habitat protection and recovery goals, requiring the identification and protection of all lands, water and air necessary to recover endangered species. To determine what exactly is critical habitat, the needs of open space for individual and population growth, food, water, light or other nutritional requirements, breeding sites, seed germination and dispersal needs, and lack of disturbances are considered. As habitat loss is the primary threat to most imperiled species, the Endangered Species Act of 1973 allowed the Fish and Wildlife Service (FWS) and National Marine Fisheries Service (NMFS) to designate specific areas as protected "critical habitat" zones. In 1978, Congress