Information from the geomagnetic field triggers a reduced adrenocortical response in a migratory bird
Information from the geomagnetic field triggers a reduced adrenocortical response in a migratory bird
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DOI：
10.1242/jeb.033332
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发表时间：
2009-09-15
影响因子：
2.8
通讯作者：
Kullberg, Cecilia
中科院分区：
文献类型：
--
作者：
Henshaw, Ian;Fransson, Thord;Kullberg, Cecilia
长途迁徙者经常穿越生态屏障，比如撒哈拉沙漠，在那里，要成功穿越需要大量的燃料。一个核心问题是，没有经验的移民如何知道什么时候应该大量装载燃料。除了内源性的节奏外，外界的线索也被认为是重要的。地磁信息已被证明会引发候鸟觅食行为和燃料沉积速率的变化。然而，这些调整的潜在机制尚不清楚。由于已知糖皮质激素皮质酮与鸟类能量调节相关的行为和生理相关，我们在这里研究了地磁线索对长途迁徙动物循环皮质酮水平的影响。正如早期的研究一样，在秋季迁徙期间捕获的幼年画眉夜莺（Luscinia Luscinia）暴露在埃及北部的模拟地磁场中，比经历瑞典东南部环境磁场的对照鸟增加了食物摄入量，获得了更高的燃料负荷。我们的研究结果进一步表明，与对照鸟相比，实验鸟面临的肾上腺皮质反应减少，因此首次表明地磁线索触发激素分泌的变化，从而使迁徙路线上的行为适当。
Long-distance migrants regularly pass ecological barriers, like the Sahara desert, where extensive fuel loads are necessary for a successful crossing. A central question is how inexperienced migrants know when to put on extensive fuel loads. Beside the endogenous rhythm, external cues have been suggested to be important. Geomagnetic information has been shown to trigger changes in foraging behaviour and fuel deposition rate in migratory birds. The underlying mechanism for these adjustments, however, is not well understood. As the glucocorticoid hormone corticosterone is known to correlate with behaviour and physiology related to energy regulation in birds, we here investigated the effect of geomagnetic cues on circulating corticosterone levels in a long-distance migrant. Just as in earlier studies, juvenile thrush nightingales (Luscinia luscinia) caught during autumn migration and exposed to the simulated geomagnetic field of northern Egypt increased food intake and attained higher fuel loads than control birds experiencing the ambient magnetic field of southeast Sweden. Our results further show that experimental birds faced a reduced adrenocortical response compared with control birds, thus for the first time implying that geomagnetic cues trigger changes in hormonal secretion enabling appropriate behaviour along the migratory route.