Thanks to noise pollution, the sharp-eyed fruit bats, also known as flying fox, have made an hasty exit from the island at Jayanti sarovar at landmark Jubilee Park.

Heightened activity in view of the Founder’s Day celebrations in the steel city on March 3 have also forced the mammals out of the island. Fruits bats are no longer found hanging from trees at the island even though preparations for Founder’s Day is yet to begin at the park.

Besides Jubilee Park, other locations of the city are also illuminated to mark J.N. Tata’s birth anniversary. The island is also decked up to suit the occasion.

“The fruit bats have left the island because of noise pollution, which includes boating at the lake. Activities will increase when preparations for Founder’s Day will begin. The bats must have used their biological clock assessment which made them understand the impending disturbances,” said ornithologist K.K. Sharma.

He explained that via biological clock, bats make an assessment well in advance about the dangers that might cause trouble to them. “Bats are very sensitive mammals and prefer to live silent zones..

The bats have made the island their home for over seven decades now.

Sharma, former head of zoology department and member of Ornithological Society of India, said the numbers of bats at the island has also decreased. “It was around 3,000 in the 70s but the figure has now dropped to around 100-150. It’s a very disturbing sign and serious efforts should be made for their conservation.

Sharma, who has done a study of fruit bats, said experts had felt the need to conserve mammals at the island during a seminar organized by him in 2010. Experts had felt that the island was an apt place for the bats. The experts had also visited the island to take stock of the situation.

“There were initial discussions to turn the island into a sanctuary for fruit bats. But things did not make any positive headway,” Sharma said, adding the flying radius of the island bats Jamshedpur, Chandil and Ghatshila. Fruit bats typically stay close to water bodies and hide in trees to protect themselves from predators such as hawks or snakes.

Sharma pointed out that the trend of bats making an exit from the island was not a good sign. “Though the bats do come back to island but noise pollution due to increased activities and traffic flow around the lake would force the mammals to permanently bid good-bye to the island.

eom