Gormally Brenna M G, van Rees Charles B, Bowers Emily, Reed J Michael, Romero L Michael
Department of Biology, Tufts University, Medford, MA 02155, USA.
Current Address: Schmid College of Science and Technology, Chapman University, Orange, CA, USA.
Conserv Physiol. 2020 Dec 30;8(1):coaa125. doi: 10.1093/conphys/coaa125. eCollection 2020.
Physiological metrics are becoming popular tools for assessing individual condition and population health to inform wildlife management and conservation decisions. Corticosterone assays can provide information on how animals cope with individual and habitat-level stressors, and the recent development of feather assays is an exciting innovation that could yield important insights for conservation of wild birds. Due to the widespread enthusiasm for feather corticosterone as a potential bioindicator, studies are needed to assess the ability of this technique to detect meaningful differences in physiological stress across a variety of stressor types and intensities. We examined feather corticosterone from 144 individuals among the 13 known breeding populations of Hawaiian gallinule (), an endangered waterbird, on the island of O'ahu. These ecologically independent subpopulations are known to have low genetic connectivity and movement rates and differ largely across a number of important conditions, including level of predator management, human disturbance, proximity to urban development and conspecific population density. This system is well suited for assessing the performance of feather corticosterone as a bioindicator of different known habitat-level threats common to this and many other conservation-reliant species. We found no statistically significant relationship between feather corticosterone and level of predator control, level of human disturbance, gallinule population density, percent urban cover or body condition across all sites despite the substantial difference in stressor magnitude in our dataset. We did find that gallinules in habitats with larger population densities were in worse body condition. These findings suggest that feather corticosterone is not a consistent indicator of anthropogenic impacts on populations. Furthermore, they suggest that feather corticosterone may be a poor bioindicator of known habitat-level threats for Hawaiian gallinules and that it should be used with caution in other avian taxa of conservation concern.
生理指标正成为评估个体状况和种群健康状况的常用工具，为野生动物管理和保护决策提供依据。皮质酮检测可以提供有关动物如何应对个体和栖息地层面压力源的信息，而羽毛检测的最新进展是一项令人兴奋的创新，可能为野生鸟类的保护带来重要见解。由于人们对羽毛皮质酮作为一种潜在生物指标的广泛关注，需要开展研究来评估该技术在检测各种压力源类型和强度下生理应激方面有意义差异的能力。我们检测了瓦胡岛上13个已知繁殖种群中144只夏威夷秧鸡（一种濒危水鸟）的羽毛皮质酮。这些生态上独立的亚种群已知遗传连通性和迁移率较低，并且在许多重要条件方面存在很大差异，包括捕食者管理水平、人类干扰、与城市发展的距离以及同种种群密度。这个系统非常适合评估羽毛皮质酮作为该物种以及许多其他依赖保护的物种常见的不同已知栖息地层面威胁的生物指标的性能。尽管我们数据集中压力源强度存在很大差异，但我们发现所有地点的羽毛皮质酮与捕食者控制水平、人类干扰水平、秧鸡种群密度、城市覆盖百分比或身体状况之间均无统计学上的显著关系。我们确实发现，种群密度较大的栖息地中的秧鸡身体状况较差。这些发现表明，羽毛皮质酮并非人为对种群影响的一致指标。此外，它们表明羽毛皮质酮可能不是夏威夷秧鸡已知栖息地层面威胁的良好生物指标，在其他受保护关注的鸟类分类群中应谨慎使用。
