West Nile virus threatening wildlife.

• Position: Your Life - Rare and endangered birds are particularly threatened - Report from University of California

West Nile virus could pose a serious threat to some species, especially rare and endangered birds, and officials are encouraged to broaden existing monitoring efforts to track the virus' movement, states a report re leased by wildlife health experts at the University of California, Davis. Prepared by a team led by Walter Boyce, director of the Wildlife Health Center, the report predicts where West Nile virus poses the greatest risk to wildlife by examining mosquito abundance in relation to bird species that "amplify" the virus and the location of rare amphibians, reptiles, birds, and mammals.

"Some level of mortality due to West Nile virus will occur in a substantial number of different bird species.... Just which ones we can't say with certainty," Boyce notes. "There is so much we don't know about this pathogen. The species that concern us most are those that have limited distribution overall or a limited population in areas with high numbers of mosquitoes."

The report includes a series of maps that vividly depict where West Nile virus poses risks to various groupings of species. Included are 27 birds, such as the brown pelican, California condor, and sandhill crane; 21 mammals, such as the kit fox, wolverine, and bighorn sheep...