A jamboree residents organised near the Kulik Bird Sanctuary in North Dinajpur’s Raiganj on Tuesday night has forced migratory birds to shift base.

Foresters said around 1 lakh migratory birds had been counted in the sanctuary till September.

“The celebration adjacent to the sanctuary (after a puja) has forced many birds to leave the core area,” said a forest employee.

Thick smoke from the open-air cooking drifted to the forest. “Loud music played on speakers made the situation worse. We are apprehending that this could affect the turnout of migratory birds next year,” a forest official said.

The sanctuary, located 3km from Raiganj town, is spread over 370 acres. It is located on the banks of the Kulik river off NH34.

Forest officials said the migratory birds, mostly from Siberia, come to the sanctuary between April and May.

Cormorants, egretes, night herons and open-bill storks are some of the common species of birds that are spotted at the sanctuary.

The birds return in December.

Forest sources said birds at Kulik had faced similar threats in 2011.

The department had noticed a sudden drop in the migratory bird population.

A survey was than conducted by Gopinathan Maheswaran, an expert, to find out the reason behind the decreasing population.

The expert had suggested that the area be declared a silence zone, more fodder be made available and picnics be stopped at the sanctuary to ensure that smoke does not disturb the avian population.

After the suggestions were implemented, there was an increase in the bird population.

“We are really worried about the menace created by some locals in the name of celebrations. We don’t have the infrastructure to stop them. I have informed the administration about this and hopefully they will take necessary steps,” said Dwiparna Dutta, the divisional forest officer of Raiganj.

One of the organisers said: “We are aware of the migratory birds’ presence in the sanctuary and we tried to keep our programme low-profile so that the birds do not get disturbed. This festival comes only

once a year and continued for a couple of days. We hope this will not create much trouble for them (the birds).”

Aravind Meena, the district magistrate, said: “Though we have no such information, nevertheless will definitely look into the matter.”