All activities, including the entry of visitors into the 15.59 sq km Nalabana bird sanctuary in Chilika have been restricted for three days in view of the annual bird count in the lagoon.

The restriction which came into force on Saturday would continue till Monday in the famous sanctuary area.

Similarly, there will be no movement of tourist boats in Mangalajodi on Monday, officials said.

"The restriction has been imposed to keep the birds undisturbed for smooth conduct of the census," said divisional forest officer (DFO) of Chilka wildlife division Bikash Ranjan Das. He added that fishing would not be restricted in other parts of the 1,100 sq km lake during the period.

Most migratory waterfowls visiting the lake are concentrated in Nalbana. Besides Nalbana, the migratory birds also descend upon Mangalajodi, Bhusandapur, Sorana Prikuda and Chadheighara islands. "No restriction has been imposed in these areas as these do not come under the sanctuary," Das said.

The enumerators are being trained on Sunday, a day before the actual count scheduled for Monday. Das said experts from the Bombay Natural History Society (BNHS), noted ornithologists, research scholars and forest and wildlife officials, forestry students of Orissa University of Agriculture and Technology (OUAT) are participting in the exercise.

For the first time ever, all 20 DFOs (wildlife) in the state are also taking part in the mammoth exercise, he added.

The annual bird census this time assumes significance in the wake of the impact of climate change on migration.