The bird census would cover the entire Chilika lake spread over nearly 1,100 sq km.
"Though bird counting will be done all over the lake, we have decided to prohibit visitor's entry to the Nalabana sanctuary where maximum birds concentrate from yesterdy.
"Except for patrolling boats, no other boat will be allowed to go near the sanctuary", said B P Acharya Divisional Forest Officer (DFO), Chilika Wildlife Division.
"Tourist boats near Nalabana may disturb birds", he said.
Thousands of winged guests, mostly from the Himalayas, Caspian region, Siberia, Kazakhstan, Lake Baikal and remote areas of Russia and neighbouring countries have arrived in Chilika to spend the winter here, he said.
"Though places like Mangaljodi, Bhusandapur, Sorana and Rambha in the lake attract the birds, Nalabana gets most of them," he said.
Wildlife officials said the ban on tourists to Nalabana would check poaching to a large extent.
"On December 25 and New Year day, incidence of poaching increases in the Lake as bird meat is much in demand in places like Berhampur, Balugaon, Cuttack and Bhubaneswar," said a senior forest official.
