title: Persistent impacts of West Nile virus on North American bird populations.
abstract: Since its introduction to North America in 1999, West Nile virus (WNV) has had devastating impacts on native host populations, but to date these impacts have been difficult to measure. Using a continental-scale dataset comprised of a quarter-million birds captured over nearly two decades and a recently developed model of WNV risk, we estimated the impact of this emergent disease on the survival of avian populations. We find that populations were negatively affected by WNV in 23 of the 49 species studied (47%). We distinguished two groups of species: those for which WNV negatively impacted survival only during initial spread of the disease (n = 11), and those that show no signs of recovery since disease introduction (n = 12). Results provide a novel example of the taxonomic breadth and persistent impacts of this wildlife disease on a continental scale. Phylogenetic analyses further identify groups (New World sparrows, finches, and vireos) disproportionally affected by temporary or persistent WNV effects, suggesting an evolutionary dimension of disease risk. Identifying the factors affecting the persistence of a disease across host species is critical to mitigating its effects, particularly in a world marked by rapid anthropogenic change.
authors.affiliation: Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO 80523;
authors.forename: T Luke
authors.initials: TL
authors.lastname: George
authors.affiliation: Center for Tropical Research, Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095; iluvsa@ucla.edu.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Harrigan
authors.affiliation: Department of Biology, Washington University, St. Louis, MO 63130;
authors.forename: Joseph A
authors.initials: JA
authors.lastname: LaManna
authors.affiliation: The Institute for Bird Populations, Point Reyes Station, CA 94956;
authors.forename: David F
authors.initials: DF
authors.lastname: DeSante
authors.affiliation: The Institute for Bird Populations, Point Reyes Station, CA 94956;
authors.forename: James F
authors.initials: JF
authors.lastname: Saracco
authors.affiliation: Center for Tropical Research, Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095; Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095.
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Smith
mesh_terms: D000818:Animals; D001715:Bird Diseases / Q000453:epidemiology / Q000235:genetics / Q000821:virology; D001717:Birds; D019143:Evolution, Molecular; D006801:Humans; D009656:North America / Q000453:epidemiology; D010802:Phylogeny; D014901:West Nile Fever / Q000453:epidemiology / Q000235:genetics / Q000662:veterinary; D014902:West Nile virus / Q000235:genetics*
keywords: West Nile virus; avian populations; demography; emerging infectious diseases; population biology