As migratory birds have started flocking the vast Chilika lake on Orissa coast, the wildlife division of the state forest department has imposed certain restrictions for the tourists visiting the lagoon during winter.Visitors are barred to enter the 15.53 sq km Nalabana bird sanctuary area inside the lagoon. The restriction on entry of visitors is imposed for the safety of the migratory birds, said the divisional forest officer, Chilika wildlife division, Abhimanyu Behera.Most of the migratory waterfowls coming to the lake are congregated in the Nalabana Island. The researchers and ornithologists, however, will be allowed to carry out their study inside the sanctuary area with prior permission from the wildlife division, he said.Besides the Nalabana, the migratory birds coming from far flung areas have also swooped in other places like Bhusandpur, Soran, Mangalajodi, Parikuda and Chadheighara islands. The visitors, however, are not restricted to go to these places as they do not come under the sanctuary area, Behera said.Every year the birds from far-flung areas beyond the Himalayan region, Iraq, Iran, Pakistan, Afghanistan visit the lake from October to mid-March to escape the biting cold in their respective habitats. This year the winged guests have started arriving in the last week of the October.The wildlife officials expressed hope that this year there may an increase in the number of birds.Improvement of sanctuary area and strict vigil on poaching are some of the reasons attracting the birds to the lake, Behera said.In the last winter, according to the sources, about 8.39 lakh birds had descended on the entire lake and 1.98 lakh of them in the Nalabana Island. In the previous year, the numbers were 6.40 lakh and 2.58 lakh respectively. "Our aim is to host more number of winged guests from different places safely during this winter," he said.He said, the wildlife organisations in collaboration with the Chilika Development Authority (CDA) have imparted training to the boat operators about the safety of the birds and how to deal with the visitors.Apart from Orissa Tourism Development Corporation (OTDC), at least three private boat operation associations are working in the lake at different points to carry the visitors inside the lake.In order to facilitate the visitors to watch the birds from a distance, the CDA has constructed a watchtower near Managalajodi. Mangaljodi is another place inside the lagoon where the migratory birds congregate in large number after Nalabana sanctuary.As Chilika is the third largest tourist puller in Orissa after Puri and Konark, the wildlife department has proposed to develop eco-tourism inside the lake and to provide trekking facilities to the tourists."We have planned to provide a short stay to the tourists inside the lake by developing small cottages and tents at different places" Behera said. The places selected for this purpose are Bramhapura, Khirisahi, Rambhartia and Mahisa Bramhapur."We have also proposed to develop 18-km long trekking programme for the tourists from New Channel to Pokharikuda" But these proposals are yet to be approved by the government, he added.The sources said, the number of tourists visiting the lake has increased from 3.9 lakh in 2004-05 to 7.03 lakh in 2006-07. 4.10 lakh tourists visited the lagoon in 2005-06.