It is one of the largest seasonal saline wetlands having an average water depth between 0.5 to 1.5 metres. By October-November each year, rain water dries up and the entire area turns into saline desert. The sanctuary supports wide variety of water birds and mammalian wildlife.
Important animals- Wolf, hyena, jackal, chinkara, wild ass, bluebull, wild boar, Indian porcupine, pale hedgehog, mongoose, rufous-tailed hare, desert fox, spiny tailed lizard etc.
Important birds : Greater flamingo, lesser flamingo, pelicans, black-necked storks, cormorant, Indian cormorant, brahmini duck, pintail, spotbill, shoveller, pochard, sandpiper, gulls, terns, stints, plovers etc.
The Sanctuary is mainly established to preserve the nesting ground of a magnificent bird; the flamingo or Greater Flamingo. It is the largest sanctuary encompassing a true saline desert, not to be found elsewhere in the world. It covers the only area in the country, where the Greater Flamingo breeds regularly in the north and northeast of Kala Dungar. Great Rann is very interesting from biological, ecological, geological and climatic points of view. It represents one of the largest seasonal saline wetland areas having the water depth ranging from 0.5 to 1.5 m. After October- November, water dries up and the area turns into saline desert.
An eco-tourist visiting the Sanctuary is exposed to fresh-cum-saline water wetland from monsoon to early winter and true saline desert from late winter to summer. He would see four hilly and rocky islands ('bets') viz., Pachchham, Khadir, Bela and Chorar, the first three being located in Kutch district and the last being located in Patan district. Khadir is the only island in true sense, other three being connected to the mainland from one or the other side.
The Pachchham island at the dist
ance of about 80 km from Bhuj, is about 25 km long and 9 km wide and supports the hill called 'Kala Dungar', which represents the highest point (438 m) within the Sanctuary. Another hill called 'Goro Dungar' is slightly shorter and narrower than Kalo Dungar. Both the hills represent rocky habitats, with or without thorny scrubs like Ganda Baval (Prosopis juliflora) and Thor (Euphorbia nivula). Khadir bet (80 km north of Rapar), having an area of about 313 sq. km supports the hill called Chhapariya Dungar, whose northern flank overlooks the mudflats of the Great Rann. Bela bet, the eastern most major hilly island in Kutch district, supports two hills namely 'Nilvo' and 'Muvano'.