BERHAMPUR: Panic gripped Chilika following the mass death of crows at Sialia and Alada Patna villages near Krushna Prasad under Nuapada range of the Chilika wildlife division on Saturday.Wildlife personnel found the carcasses of 20 crows from Sialia and 11 from Alada Patna."The exact reason of the sudden death of crows in such large numbers is yet to be known. It can be ascertained only after a postmortem," Gangadhara Sahu, an officer of the Nuapada wildlife range, said. He added that doctors examining the circumstances leading to the death of the crows have taken two samples of the carcasses from Sialia. They were set on fire after a thorough examination.The wildlife division is planning to send the samples to the National Institute of High Security Animal Diseases (NIHSAD) in Bhopal to confirm the virus of avian influenza in the crows. Sahu added that they would decide the future course of action after getting the preliminary report from the local veterinary hospital. The range officer, however, said they did not find any migratory bird there dead "So far, we have not found any migratory bird in the Nuapada range area of the lake dead," he said.The lake has seen the arrival of around six lakh winged guests this year. Wildlife officials said they are keeping a strict vigil on the lake following the recovery of carcasses of crows.The birds, mostly from beyond the Himalayas in northern Eurasia, the Caspian region, Siberia, Kazakh, Lake Baikal and the remote areas of Russia and neighbouring countries visit Chilika every winter and start their homeward journey before the onset of summer.