Chilika Lagoon (Orissa), with an area of 1000 sq. km is one of the hotspots of biodiversity in India. It is a part freshwater lake and part saltwater estuary. Its high productivity and the presence of a variety of habitats in and around the lake allow the proliferation of an amazing number of wildlife species, including birds. Chilika is one of the terminuses on the migratory birds' flyways.
Best Season: October to April
The lagoon hosts over 160 species of birds in the peak migratory season, and at least 97 of these are intercontinental migrants. Birds from as far as the Caspian Sea, Lake Baikal, Aral Sea and other remote parts of Russia, Kirghiz steppes of Mongolia, Central and southeast Asia, Ladakh and Himalayas come here. These birds travel great distances, but it must be stressed, that the migratory birds probably follow much longer routes than the straight lines, possibly up to 12,000 km, to reach Chilika. Of the species recorded, 32% are waterfowl, 23% are waders and 45% are terrestrial, including 14 types of birds of prey.
Huge flocks of birds are scattered throughout the lake, however major concentration in terms of species abundance is on Nalbana island, declared a bird sanctuary in 1973. This 32 sq. km island gets completely submerged during the monsoons. As the monsoon waters recede, the island gradually emerges. At the beginning of the migratory season, long-legged waders and dabbling species are predominant. As the island gradually dries up, small wading species congregate on the islands. During December-January a large number of ducks, fish-eating birds and smaller waders flock to feed or roost. By summer almost all the birds leave and only a few songbirds and resident shorebirds remain. Other areas where high concentrations of birds are found include Gerasara, Parikud island, and the western shores of the Northern sector.
A waterfowl census carried out in 1991 recorded huge numbers of Shovelers (99,670), Pintails (50,690), Coots (46,280), Gadwalls (30,890) and Great Crested Grebes (15,692).
One of the most fascinating sights in Chilika is that of large flocks of flamingos feeding in the shallow waters of the lagoon. Flamingos come to Chilika from Iran and the Rann of Kutch in Gujarat. Recently, they have started staying for longer periods in larger numbers, and some remain the year round. Other Long-legged waders seen around Nalbana are Lesser Flamingos, Grey and Purple Herons, Egrets, Spoonbills, Storks and White Ibis. Compact gregarious flocks of Brahminy Ducks, as well as Shovelers, Pintails, Gadwall, Teals, Pochards and Geese, can be seen all around Nalbana island.
The short-legged shorebirds restrict themselves to a narrow band along the shifting shores of the lake and islands. These include Plovers, the Collard Pratincole, Ruff, Dunlin, Snipes and Sandpipers. Larks, Wagtails and Lapwings are also found on the mudflats. Venturing into deeper water are the longer-legged Avocets, Stilts and Godwits. The vegetated areas of the lake support moorhens, Coots and Jacanas. Pond Herons and Night Herons can be seen along the shores as also Kingfishers and the Roller. The Little Cormorant is seen on perches around the lake, and is increasingly using the bunds being built by fishermen.
There are many raptors found around the lagoon with Black Kite and Brahminy Kite being more common. Marsh Harriers and Pallas's Fishing Eagles are seen around the flocks of ducks and coots, specially at Nalbana. The endangered White-bellied Sea Eagle is seen fairly often. Winter visitors include the Kestrel and the globally threatened Peregrine Falcon.
A few rare birds recorded at Chilika are the Spoonbill Sandpiper (Eurynorhynchus pygmeus), the Asian Dowitcher (Limnodromus semipalmatus) and the Goliath Heron (Ardea goliath). The Spoonbill Sandpiper is a rare winter migrant. It has been recorded only four times in India over the last fifty years. One was seen at Chilika in 1981. This tiny wader migrates all the way from Siberia to winter in India. A small number of Asian Dowitcher regularly visit Chilika. This bird is a rare vagrant in India. As many as 41 Dowitchers have been seen at Chilika at one time. The huge and rare Goliath Heron is another species spotted in Chilika.
At least five species of birds have been spotted breeding on Nalbana island at the end of March, when the island is fairly dry. These are the Little Tern, Gull-billed Tern, Black-winged Stilt, Eastern Skylark and Collard Pratincole. Several other birds, including several terrestrial birds, probably breed around the area.
During a recent survey nesting colonies of Gull-billed Terns and River Terns
were observed on the Nalabana Island which appear to be the largest known breeding colonies for these two species. Moreover, the breeding records of
Gull-billed Tern in Chilika are a southern breeding range extension for the species, as its known breeding sites from the Indian Subcontinent are
Pakistan on the west coast and Sunderbans (West Bengal) on the east coast. The Indian River Tern which has restricted distribution range (India,
Pakistan, Bangladesh, Nepal, South West China, Myanmar, and Malayan Peninsula) is one of the least studied species. Though River Tern breeds
sporadically throughout India (scarce in southern peninsular India), smaller number of nests were noticed in each colony.