As many as 51 crows have died of bird flu in Maharashtra's Latur district, and authorities have started taking preventive measures to contain the spread of the disease, an official said on Sunday. A report from the Bhopal Veterinary Laboratory that arrived on Saturday revealed that the crows in Udgir city have died of avian influenza (H5N1), Deputy Commissioner for Animal Husbandry Dr Shridhar Shinde told PTI.