KENDRAPARA: Nesting habitats of the salt-water crocodiles in the rivers and creeks of Bhitarkanika National Park are now being mapped through the application of Geographical Information System (GIS) and Global Positioning System (GPS) . The main thrust is to ascertain prospective nesting areas using GPS and GIS thus minimising the spectral range of the investigated regions, said Dr Sudhakar Kar, a noted herpetologist and senior research officer of Forest and Wildlife Department. Nesting is protracted and complex. It is likely that courtship occurs in May and June and peaks six to eight weeks before nesting. During this period, crocodiles remain in their inland habitats of mangrove swamps, added the herpetologist. Females lay between 45 and 60 eggs per clutch and the eggs will incubate for about 75 days, hatching in late July or early August. As the crocodile eggs cannot survive flooding for more than 12 hours, the nests are built above the water mark at an elevated level. The female crocodiles in Bhitarkanika do not always remain near the nest. However, toward the end of incubation, females visit the nest more frequently and in many cases help the hatchlings emerge from their eggs. The forest officials last year counted 1,498 crocodiles and 56 nests of crocodiles in Bhitarkanika, said Kar.