At least five common birds, including robins and bluebirds, suffered sustained, large-scale population declines because of West Nile virus, a new study suggests.
The mosquitoborne virus, already known to sicken and kill wildlife as well as people, was first documented in the United States in 1999. Now, birders' records give the first look at what the disease has done to whole bird populations, say researchers from the Smithsonian Migratory Bird Center in Washington, D.C., and the Consortium for Conservation Medicine in New York City.
Shannon L. LaDeau of the Smithsonian turned to records from the annual nationwide Breeding Bird Survey. Each June, volunteer surveyors drive predetermined 25-mile routes along secondary roads and stop every half mile for 3 minutes to count birds.