Our current understanding of West Nile virus in upland game birds

Abstract

AbstractSince its introduction to the United States in 1999, West Nile virus (WNV) rapidly spread and is now endemic throughout much of North America. West Nile virus has impacted many North American birds, including suspected population‐level declines. However, the potential effects of WNV on upland game bird species remain largely unknown. We reviewed the published literature on WNV infection in upland game birds, with the majority comprised of experimental infection trials, serologic surveys, and natural infection reports. Early WNV research indicated that some species within Galliformes are not susceptible to WNV‐associated disease, but reports were primarily based on studies in domestic fowl with small sample sizes. Research on greater sage‐grouse (Centrocercus urophasianus) and ruffed grouse (Bonasa umbellus) confirmed both species are highly susceptible to WNV‐associated morbidity and mortality, which highlights the need to better understand the potential effects of WNV on other upland game bird species. Serological data using primarily hunter‐harvested, greater sage‐grouse samples revealed low seroprevalence among several populations, indicating WNV may pose a risk to greater sage‐grouse populations. Currently, data are lacking on the effects of WNV in wild turkeys (Meleagris gallopavo), for which low recruitment rates and depressed population numbers have been documented across parts of the eastern United States. Despite low virulence of WNV in experimentally‐infected domestic turkeys, sporadic cases of WNV‐associated morbidity are reported in wild turkeys. Serosurveys that include wild turkeys are limited in number, sample size, and geographic distribution, but available results suggest that a substantial percentage of WNV‐infected wild turkeys survive. Research focused on experimental infection trials, serosurveys, and documenting natural infections, along with land cover and vector studies, are necessary to provide a more complete understanding of the potential population level implications WNV may have on various upland game birds, including wild turkey.