Forest Wildlife Populations and Research Group, Minnesota Department of Natural Resources, 1201 E Highway 2, Grand Rapids, Minnesota 55744, USA.
Wildlife Health Program, Minnesota Department of Natural Resources, 5463 W Broadway Avenue, Forest Lake, Minnesota 55025, USA.
J Wildl Dis. 2022 Jan 1;58(1):30-39. doi: 10.7589/JWD-D-21-00018.
West Nile virus (WNV) was introduced to North America two decades ago, but for many species, including Ruffed Grouse (Bonasa umbellus), the effects of WNV on individuals and populations remain poorly understood. Recent studies suggest the effect of WNV on Ruffed Grouse might vary among geographic regions, depending on habitat conditions. We studied WNV in Minnesota, US, during 2018-19, in a region known to have abundant Ruffed Grouse habitat and a population cycling around a stable long-term average. We worked with cooperating hunters to collect hearts, feathers, and blood on filter strips from birds harvested in the fall to examine exposure to the virus. We detected antibodies to WNV or a flavivirus (probably WNV) in 12.5% and 12.3% of birds in 2018 and 2019, respectively. However, we did not isolate the virus from any heart samples, indicating that exposed birds were not experiencing an active infection of WNV at the time of harvest. Our findings indicate that, although Minnesota Ruffed Grouse are exposed to WNV, some birds mount a successful immune response and survive. However, our sampling approach did not account for birds that might have become infected over the summer and died, so it is unknown how much WNV mortality occurred before the fall harvest. Birds lost to WNV over the summer could reduce the number of birds that hunters see in the fall, thus reducing the quality of their hunting experiences. Management options for mitigating WNV impacts and other stressors consist primarily of providing high-quality Ruffed Grouse habitat that produces birds in good condition that are more likely to recover from infection.
西尼罗河病毒（WNV）二十年前传入北美，但对于包括松鸡（Bonasa umbellus）在内的许多物种，WNV 对个体和种群的影响仍知之甚少。最近的研究表明，WNV 对松鸡的影响可能因地理区域而异，具体取决于栖息地条件。我们在 2018-19 年期间对美国明尼苏达州进行了 WNV 研究，该地区已知有丰富的松鸡栖息地，其种群数量在长期稳定的平均值上下波动。我们与合作猎人合作，从秋季收获的鸟类身上的过滤条上收集心脏、羽毛和血液，以检查它们对病毒的暴露情况。我们在 2018 年和 2019 年分别检测到 12.5%和 12.3%的鸟类对 WNV 或黄病毒（可能是 WNV）产生了抗体。然而，我们没有从任何心脏样本中分离出病毒，这表明在收获时，暴露的鸟类没有经历 WNV 的急性感染。我们的研究结果表明，尽管明尼苏达州的松鸡接触到了 WNV，但一些鸟类成功地产生了免疫反应并存活了下来。然而，我们的采样方法没有考虑到那些可能在夏季感染并死亡的鸟类，因此，在秋季收获之前，WNV 导致的死亡率是未知的。夏季死于 WNV 的鸟类可能会减少猎人在秋季看到的鸟类数量，从而降低他们的狩猎体验质量。减轻 WNV 影响和其他压力源的管理选择主要包括提供高质量的松鸡栖息地，以产生状况良好的鸟类，这些鸟类更有可能从感染中恢复。
