West Nile Virus as a Cause of Death Among Endangered Eastern Loggerhead Shrikes, Lanius ludovicianus migrans , in West St. Paul, Manitoba

In July 2006, three Eastern Loggerhead Shrike ( Lanius ludovicianus migrans ) nestlings were found dead in a nest in West St. Paul, near Winnipeg, Manitoba. The Eastern Loggerhead Shrike is an endangered form in Canada and populations are in decline. Reverse transcription-polymerase chain reaction and immunohistochemical staining detected West Nile virus in the tissues of the nestlings indicating the cause of death. This is the first confirmed report of West Nile virus in wild populations of Eastern Loggerhead Shrikes in North America. These findings will challenge conservation biologists in their efforts to develop recovery and management plans for the endangered Eastern Loggerhead Shrike, as well as in the implementation of captive rearing programs.