Great Basin Bird Observatory, Reno, Nevada, United States of America.
U.S. Forest Service Rocky Mountain Research Station, Boise, Idaho, United States of America.
PLoS One. 2021 Jan 27;16(1):e0237621. doi: 10.1371/journal.pone.0237621. eCollection 2021.
The Pinyon Jay is a highly social, year-round inhabitant of pinyon-juniper and other coniferous woodlands in the western United States. Range-wide, Pinyon Jays have declined ~ 3-4% per year for at least the last half-century. Occurrence patterns and habitat use of Pinyon Jays have not been well characterized across much of the species' range, and obtaining this information is necessary for better understanding the causes of ongoing declines and determining useful conservation strategies. Additionally, it is important to better understand if and how targeted removal of pinyon-juniper woodland, a common and widespread vegetation management practice, affects Pinyon Jays. The goal of this study was to identify the characteristics of areas used by Pinyon Jays for several critical life history components in the Great Basin, which is home to nearly half of the species' global population, and to thereby facilitate the inclusion of Pinyon Jay conservation measures in the design of vegetation management projects. To accomplish this, we studied Pinyon Jays in three widely separated study areas using radio telemetry and direct observation and measured key attributes of their locations and a separate set of randomly-selected control sites using the U. S. Forest Service's Forest Inventory Analysis protocol. Data visualizations, principle components analysis, and logistic regressions of the resulting data indicated that Pinyon Jays used a distinct subset of available pinyon-juniper woodland habitat, and further suggested that Pinyon Jays used different but overlapping habitats for seed caching, foraging, and nesting. Caching was concentrated in low-elevation, relatively flat areas with low tree cover; foraging occurred at slightly higher elevations with generally moderate but variable tree cover; and nesting was concentrated in slightly higher areas with high tree and vegetation cover. All three of these Pinyon Jay behavior types were highly concentrated within the lower-elevation band of pinyon-juniper woodland close to the woodland-shrubland ecotone. Woodland removal projects in the Great Basin are often concentrated in these same areas, so it is potentially important to incorporate conservation measures informed by Pinyon Jay occurrence patterns into existing woodland management paradigms, protocols, and practices.
松鸦是一种高度社会化的鸟类，终年栖息在美国西部的松柏和其他针叶林地区。在整个范围内，松鸦的数量在过去半个世纪以来每年减少约 3-4%。在该物种的大部分分布范围内，松鸦的出现模式和栖息地利用情况并没有得到很好的描述，因此获取这些信息对于更好地了解持续减少的原因以及确定有用的保护策略是必要的。此外，了解有针对性地去除松柏林地（一种常见且广泛的植被管理实践）是否以及如何影响松鸦也很重要。本研究的目的是确定松鸦在大盆地（该物种全球种群的近一半都生活在这里）中几个关键生活史组成部分所使用的区域特征，从而促进将松鸦保护措施纳入植被管理项目的设计中。为了实现这一目标，我们使用无线电遥测和直接观察在三个相距甚远的研究区域研究了松鸦，并使用美国林务局的森林清查分析协议测量了它们的位置和一组单独的随机选择的对照点的关键属性。对这些数据进行可视化、主成分分析和逻辑回归表明，松鸦使用了松柏林地中独特的栖息地子集，进一步表明松鸦在不同但重叠的栖息地中用于种子埋藏、觅食和筑巢。埋藏集中在低海拔、相对平坦且树木覆盖率低的地区；觅食发生在海拔略高的地区，树木覆盖通常适中但变化较大；筑巢集中在海拔略高、树木和植被覆盖率高的地区。这三种松鸦行为类型都高度集中在靠近林地-灌木带的松柏林地的低海拔带内。大盆地的林地清除项目通常集中在这些相同的区域，因此，将基于松鸦出现模式的保护措施纳入现有的林地管理范例、协议和实践中是非常重要的。
