Studies of West Nile virus (WNV) are prevalent in avian, equine, and human health literature over the past 15 years. What remain poorly understood are immune and physiological mechanisms that promote survival of WNV infection in natural populations. We captured downy woodpeckers, house finches, and northern cardinals before, during, and after a local WNV outbreak to determine seroprevalence of immunoglobulin M (IgM) antibodies to WNV in the local bird population. Variation in physiological traits associated with a history of WNV infection was assessed in these free-living avian hosts. The presence of WNV antibodies differed among the three species. The findings also reveal phenotypic qualities of birds that survived the virus, and potential costs associated with carrying the virus. Body condition, innate immune function, and antioxidant capacity differed significantly among birds with and without antibodies to WNV. Northern cardinals with WNV IgM were in significantly better body condition. Individuals of all three species with WNV IgM had significantly greater bacterial killing ability. Finally, individuals of all three species with WNV IgM had significantly lower total antioxidant capacity. The findings reveal phenotypic qualities of birds that survived West Nile virus, and potential costs associated with carrying the virus.