Stewart Nathan D, Mastromonaco Gabriela F, Burness Gary
Environmental and Life Sciences Graduate Program, Trent University, Peterborough, Ontario, Canada.
Reproductive Physiology, Toronto Zoo, Toronto, Ontario, Canada.
PeerJ. 2020 Feb 18;8:e8590. doi: 10.7717/peerj.8590. eCollection 2020.
Island rodents are often larger and live at higher population densities than their mainland counterparts, characteristics that have been referred to as "island syndrome". Island syndrome has been well studied, but few studies have tested for island-mainland differences in stress physiology. We evaluated island syndrome within the context of stress physiology of white-footed mice () captured from 11 islands and five mainland sites in Thousand Islands National Park, Ontario, Canada. Stress physiology was evaluated by quantifying corticosterone (a stress biomarker), the primary glucocorticoid in mice, from hair and its related metabolites from fecal samples. White-footed mice captured in this near-shore archipelago did not display characteristics of island syndrome, nor differences in levels of hair corticosterone or fecal corticosterone metabolites compared with mainland mice. We suggest that island white-footed mice experience similar degrees of stress in the Thousand Islands compared with the mainland. Although we did not find evidence of island syndrome or differences in glucocorticoid levels, we identified relationships between internal (sex, body mass) and external (season) factors and our hormonal indices of stress in white-footed mice.
岛屿啮齿动物通常比它们在大陆的同类体型更大，且种群密度更高，这些特征被称为“岛屿综合征”。岛屿综合征已得到充分研究，但很少有研究测试岛屿和大陆在应激生理学方面的差异。我们在从加拿大安大略省千岛湖国家公园的11个岛屿和5个大陆地点捕获的白足鼠的应激生理学背景下评估了岛屿综合征。通过量化毛发中的皮质酮（一种应激生物标志物）及其粪便样本中的相关代谢物（小鼠体内主要的糖皮质激素）来评估应激生理学。在这个近岸群岛捕获的白足鼠没有表现出岛屿综合征的特征，与大陆小鼠相比，毛发皮质酮或粪便皮质酮代谢物水平也没有差异。我们认为，与大陆相比，千岛湖的岛屿白足鼠经历的应激程度相似。虽然我们没有找到岛屿综合征或糖皮质激素水平差异的证据，但我们确定了内部（性别、体重）和外部（季节）因素与我们白足鼠应激激素指标之间的关系。
