Influence of urban edges on stress in an arboreal mammal: a case study of squirrel gliders in southeast Queensland, Australia
Influence of urban edges on stress in an arboreal mammal: a case study of squirrel gliders in southeast Queensland, Australia
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DOI：
10.1007/s10980-012-9790-8
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发表时间：
2012-12-01
影响因子：
5.2
通讯作者：
Bradley, Adrian
中科院分区：
文献类型：
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作者：
Brearley, Grant;McAlpine, Clive;Bradley, Adrian
人们越来越认识到，生态研究必须将其重点从基于格局 - 过程关系的推断扩展到对生态和生理过程的直接测量。生理评估很重要，因为脊椎动物通过启动应激反应来应对不可预测的有害刺激。然而，众多新的且可能产生压力的人为压力（包括与城市边缘相关的压力）过度激活急性应激反应，有可能导致慢性应激，增加对疾病的易感性，降低繁殖力和存活率。个体对与相邻受干扰城市基质（例如主干道与次干道）具有不同对比度的边缘栖息地的生理反应，可能有助于深入了解它们在破碎化城市景观中的生存可能性。尽管城市化导致的野生动物种群动态变化已有记录，但直到最近才对生理后果进行了研究。我们通过澳大利亚昆士兰州东南部破碎化城市景观中的蜜袋鼯（Petaurus norfolcensis）案例研究来解决这个问题。我们使用毛发样本对个体蜜袋鼯的毛发皮质醇水平进行比较，以此作为潜在压力的一个指标。我们应用了一种按斑块聚类的线性混合效应建模方法，以量化场地层面的栖息地因素以及与边缘对比度相关的相对丰度对毛发皮质醇水平的影响。我们发现边缘类型对毛发皮质醇水平有很强的正向影响；但这取决于一个场地中大量树洞的可获取性。我们得出结论，作为压力指标的个体毛发皮质醇浓度在内部栖息地最低，在靠近主干道的边缘栖息地最高。此外，栖息在靠近居民区和次干道且边缘对比度低的栖息地以及含有大量树洞的蜜袋鼯，其毛发皮质醇水平处于中低水平。这凸显了这些栖息地对于在城市景观中保护诸如蜜袋鼯等树栖哺乳动物的潜在重要性。
There is growing recognition that ecological research must expand its focus beyond inference based on pattern-process relationships to the direct measurement of ecological and physiological processes. Physiological assessment is important because vertebrates cope with unpredictable and noxious stimuli by initiating a stress response. However, an over-activation of the acute stress response by numerous novel and potentially stressful anthropogenic pressures, including those associated with urban edges, has the potential to generate chronic stress and a greater susceptibility to disease, reduce fecundity and survivorship. An individual's physiological response to edge habitats with varying degrees of contrast to the adjacent disturbed urban matrix (e.g. major vs. minor roads), may provide insight into their survival likelihood in fragmented urban landscapes. Although demographic changes in wildlife resulting from urbanization have been documented, only recently have physiological consequences been examined. We addressed this problem using a case study of the squirrel glider (Petaurus norfolcensis) in the fragmented urban landscape of southeast Queensland, Australia. Hair samples were used to enable a comparison of hair cortisol levels in individual squirrel gliders, providing an indication of potential stress. We applied a linear mixed-effect modeling approach clustered by patch to quantify the influence of site-level habitat factors and relative abundance comparative to edge contrast on hair cortisol levels. We found that edge type had a strong positive effect on hair cortisol levels; but this depended on the availability of abundant nest hollows at a site. We conclude that individual hair cortisol concentration, providing an index of stress, was lowest in interior habitats and highest in edge habitats adjacent to major roads. Furthermore, gliders occupying low edge contrast habitats adjacent to residential areas and minor roads, and containing abundant tree nest hollows, had low-moderate hair cortisol levels. This highlights the potential importance of these habitats for the conservation of arboreal mammals such as the squirrel glider in urban landscapes.