Greater sage-grouse survival varies with breeding season events in West Nile virus non-outbreak years

Greater Sage-Grouse (Centrocercus urophasianus) are a species of conservation concern and are highly susceptible to mortality from West Nile virus (WNV). Culex tarsalis, a mosquito species, is the suspected primary vector for transmitting WNV to sage-grouse. We captured, radio-tagged, and monitored female sage-grouse to estimate breeding season (April 15‒September 15) survival 2016-2017. Deceased sage-grouse were tested for active WNV; live captured and hunter harvested sage-grouse were tested for WNV antibody titers. Additionally, we trapped mosquitoes with CO2 baited traps 4 nights per week (542 trap nights) to estimate WNV minimum infection rate (MIR). Eight sage-grouse mortalities occurred during the WNV seasons of 2016 and 2017; 5 had recoverable tissue, and one of 5 tested positive for WNV infection. Survival varied temporally with sage-grouse biological seasons, not WNV seasonality. Survival was 0.68 (95% CI= 0.56–0.78; n=74) during the reproductive season (April 1−September 15)....