Saskatchewan Mosquitoes and West Nile Virus

West Nile virus and wild birds West Nile virus (WN) is a virus of wild birds, transmitted from bird to bird primarily by mosquitoes. Native to southern Europe, the Middle East and Africa, the virus arrived in North America in 1999 and spread quickly across the continent. Over 225 species of birds have been reported as infected with WN; some of these species, such as members of the crow family, suffer severe disease and often die from WN infection, while others appear to tolerate infection without becoming ill. The American Crow, Blackbilled Magpie, Blue Jay and Common Raven, are used as indicator species because their high and rapid death rates allow the spread of the virus to be monitored.