the office of the salt superintendent, had all the mounds of salt thrown back into the wells and shut down the salt industry leading to considerable economic misery to the people. Establishment of bird sanctuary As a bird sanctuary it was the find of Peter Michel Jackson, famous British ornithologist, and honorary secretary of the Delhi Birdwatching Society, who wrote to Prime Minister of India, Indira Gandhi, founder of the society, in 1970 about the need to declare the Sultanpur jheel near Delhi, a bird sanctuary, and she asked him to take her there. She had to cancel at the last minute, but later instructed then Chief Minister of Haryana, Bansi Lal, to protect the wetland, as a result the area was declared a Bird sanctuary in 1972. In July 1991 the reserve was upgraded to a National Park. It has an area of 1.43 km². Out of total 10,005 species of birds in the world, nearly 370 species migrate to India due to seasonal changes, including 175 long-distance migration species that use the Central air Asian Flyway route, and among those over 250 species of birds have been sighted at this protected area. Earlier before the construction of bandhs and drainage areas around Sultanpur remained waterlogged and attracted a large numbers of migratory birds and hunters, many from the Diplomatic Corps at Delhi. Now however the bird sanctuary is artificially revived using pumped water from the Yamuna. Visitors are required to pay a ₹5.00 entry fee and show identity card to visit Sultanpur National Park. Resident birds Resident birds include the common hoopoe, paddyfield pipit, purple sunbird, little cormorant, Indian cormorant, common spoonbill, grey francolin, black francolin, Indian roller, white-throated kingfisher, Indian spot-billed duck, painted stork, black-necked stork, white ibis, black-headed ibis, little egret, great egret, cattle egret, crested lark, red-vented bulbul, rose-ringed parakeet, red-wattled lapwing, shikra, Eurasian collared dove, red collared dove, laughing dove, spotted owlet, rock pigeon, magpie robin, greater coucal, weaver bird, bank mynah, common mynah and Asian green bee-eater. Migratory birds Every year over a hundred migratory bird species visit here to feed. In winter the sanctuary provides is a panorama of migratory birds such as Siberian crane, greater flamingo, ruff, black-winged stilt, Eurasian teal, common greenshank, northern pintail, yellow wagtail, white wagtail, northern shoveller, rosy pelican, spot-billed pelican, gadwall, wood sandpiper, spotted sandpiper, Eurasian wigeon, black-tailed godwit, spotted redshank, starling, bluethroat and long-billed pipit.