Wild Birds, a Source of Reticuloendotheliosis Virus Infection for the Endangered Attwater's Prairie-Chicken ( Tympanuchus cupido attwateri)?

Reticuloendotheliosis virus (REV) infects a wide range of avian species. Since 1998, when it was first reported in a captive flock of the endangered Attwater's Prairie-chicken ( Tympanuchus cupido attwateri; APC), REV has plagued APC recovery efforts. While REV frequently occurs in captive bird flocks throughout the world, including commercial poultry, the reservoir for initial infection of flocks is poorly understood. From 2008-16, 412 blood samples and 216 liver samples collected from 32 species of birds on or near Attwater Prairie Chicken National Wildlife Refuge in Colorado County, Texas, US, and 89 blood samples obtained from a Texas game farm that provides thousands of Northern Bobwhites ( Colinus virginianus ) and Ring-necked Pheasants ( Phasianus colchicus ) for hunting throughout Texas, were tested for REV by real-time PCR. Of the 717 samples, one liver sample from a Savannah Sparrow ( Passerculus sandwichensis ) and three blood samples from game farm Ring-necked Pheasants tested positive for REV. These data, although limited, indicate a low prevalence of REV in birds sharing or in close proximity to APC habitat. More-extensive surveillance testing is warranted to determine the spatial and temporal dynamics of REV in wild bird populations and the relative role these birds may play as potential reservoirs for maintaining REV infections in both the wild and captive setting.