LUCKNOW, May 17 -- Tiger reserves in the state are also on alert after the death of two big cats afflicted with bird flu -- one each at the Gorakhpur and the Kanpur zoos. Though open for visitors, tiger reserves and wildlife sanctuaries have instructed their staff to watch out for abnormal behaviour among wild animals. They have also been told to keep track of birds dying inside the sanctuary. "Tiger reserves hardly get the impact of bird flu as wild animals here are far from human contact or reach. But we have instructed our staff to remain alert and watch out for any sign or suspicion," said Dudhwa Tiger Reserve director H Rajamohan. All zoos in the state and the Etawah Lion Safari have been closed for visitors till May 20. Bird flu was confirmed in the tigress Shakti which died in Gorakhpur on May 7 and the lion Pataudi which succumbed in Kanpur on May 15. Asked what is the infection threat if domestic animals or birds do not enter the tiger reserve, Rajamohan replied, "The focus is on local migratory birds such as stork. The season for long-distance migratory birds is over but local birds still migrate from one part of a forest to another." These migratory birds stop in between, sometimes in areas where human settlements and domestic animals are present. The threat arises if the virus has already spread among birds found in human settlements. The staff in reserves have been divided for separate zones - core, buffer and outer. In each zone, staff and veterinarians have been tasked with watching and reporting any sign of bird flu or death of avians. Till now, only two animal samples have confirmed bird flu, that of the tigress and the lion. Samples of forest staff and other zoo animals have been sent to the National Institute of High Security Animal Disease, Bhopal....