Greater Sage-Grouse (Centrocercus urophasianus) is a species of conservation concern and is 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 to 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 1 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 to September 15). Mammalian predators were the leading suspected cause of mortality (40%), followed by unknown cause (25%), avian predation (15%), unknown predation (15%), and WNV (5%). These results indicate WNV was not a significant driver of adult sage-grouse survival during this study. Three sage-grouse (1.9%; 95% CI: 0.5–5.9%) contained WNV antibodies. We captured 12,472 mosquitoes of which 3,933 (32%) were C. tarsalis. The estimated WNV MIR of C. tarsalis during 2016 and 2017 was 3.3 and 1.6, respectively. Our results suggest sage-grouse in South Dakota have limited exposure to WNV, and WNV was not a significant source of sage-grouse mortality in South Dakota during 2016 and 2017. Based on our finding that a majority of sage-grouse in South Dakota are susceptible to WNV infection, WNV could potentially have an impact on the population during an epizootic event; however, when WNV is at or near-endemic levels, it appears to have little impact on sage-grouse survival.

中文翻译：

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在西尼罗河病毒非爆发年份，更大的鼠尾草存活率随繁殖季节事件而变化

大鼠尾草 (Centrocercus urophasianus) 是一种受到保护的物种，极易因西尼罗河病毒 (WNV) 而死亡。Culex tarsalis 是一种蚊子，被怀疑是将 WNV 传播给鼠尾草的主要媒介。我们捕获、无线电标记和监测雌性鼠尾草松鸡，以估计 2016-2017 年的繁殖季节（4 月 15 日至 9 月 15 日）存活率。对死去的鼠尾草进行了活性 WNV 检测；测试了活捕获和猎人收获的鼠尾草松鸡的 WNV 抗体滴度。此外，我们每周 4 晚（542 个陷阱之夜）用 CO2 诱捕器诱捕蚊子，以估计 WNV 最小感染率 (MIR)。在 2016 年和 2017 年的 WNV 季节期间发生了 8 例鼠尾草死亡，其中 5 例具有可恢复的组织，5 例中有 1 例的 WNV 感染检测呈阳性。生存时间随鼠尾草生物季节而变化，而不是 WNV 季节性。在生殖季节（4 月 1 日至 9 月 15 日），存活率为 0.68（95% CI：0.56-0.78；n = 74）。哺乳动物捕食者是导致死亡的主要原因（40%），其次是未知原因（25%）、鸟类捕食（15%）、未知捕食（15%）和西尼罗河病毒（5%）。这些结果表明，在这项研究中，WNV 并不是成年鼠尾草存活的重要驱动因素。三只鼠尾草 (1.9%; 95% CI: 0.5–5.9%) 含有 WNV 抗体。我们捕获了 12,472 只蚊子，其中 3,933 只 (32%) 是 C. tarsalis。2016 年和 2017 年估计的跗跗 WNV MIR 分别为 3.3 和 1.6。我们的结果表明，南达科他州的鼠尾草对 WNV 的暴露有限，和 WNV 不是 2016 年和 2017 年南达科他州鼠尾草死亡率的重要来源。根据我们的发现，南达科他州的大多数鼠尾草易感染 WNV，WNV 可能会对人口产生潜在影响。流行病事件；然而，当 WNV 处于或接近流行水平时，它似乎对鼠尾草的生存几乎没有影响。