Body temperature maintenance acclimates in a winter-tenacious songbird
Body temperature maintenance acclimates in a winter-tenacious songbird
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冬季顽强鸣禽的体温维持适应环境
DOI：
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发表时间：
2020
影响因子：
2.8
通讯作者：
Z. Cheviron
中科院分区：
文献类型：
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作者：
Maria Stager;Nathan R. Senner;B. Tobalske;Z. Cheviron
热产生和耗散机制的灵活性为恒温动物提供了与外部需求相匹配的热调节策略的能力。然而，这两种机制在多大程度上解释了体温调节的季节性变化却很少被探索。在这里，我们提供了关于鸟类体温调节的新数据，以研究鸟类如何改变产热和热保存机制来应对环境条件的变化。我们对黑眼juncos （Junco hyemalis）进行了不同时间的慢性冷驯化，随后量化了它们的代谢率、热导率和维持常温的能力。冷适应鸟类通过调节产热（提高顶点代谢率）和热保存（降低传导性）两方面的性状来改善体温调节。顶代谢率迅速增加，但在冷暴露1周后趋于稳定。相比之下，电导率的变化仅在低温暴露9周后才发生。因此，在整个实验过程中，维持体温的能力持续改善，但这种改善的机制随着时间的推移而改变。我们的研究结果表明，鸟类能够根据温度线索调整体温调节策略，并揭示鸟类可能结合多种反应来满足其环境的特定需求。摘要：黑眼juncos通过在不同的时间点改变不同的生理特征来响应外部温度信号，从而在寒冷中维持正常体温。
ABSTRACT Flexibility in heat generation and dissipation mechanisms provides endotherms the ability to match their thermoregulatory strategy with external demands. However, the degree to which these two mechanisms account for seasonal changes in body temperature regulation is little explored. Here, we present novel data on the regulation of avian body temperature to investigate how birds alter mechanisms of heat production and heat conservation to deal with variation in ambient conditions. We subjected dark-eyed juncos (Junco hyemalis) to chronic cold acclimations of varying duration and subsequently quantified their metabolic rates, thermal conductance and ability to maintain normothermia. Cold-acclimated birds adjusted traits related to both heat generation (increased summit metabolic rate) and heat conservation (decreased conductance) to improve their body temperature regulation. Increases in summit metabolic rate occurred rapidly, but plateaued after 1 week of cold exposure. In contrast, changes to conductance occurred only after 9 weeks of cold exposure. Thus, the ability to maintain body temperature continued to improve throughout the experiment, but the mechanisms underlying this improvement changed through time. Our results demonstrate the ability of birds to adjust thermoregulatory strategies in response to thermal cues and reveal that birds may combine multiple responses to meet the specific demands of their environments. Summary: Dark-eyed juncos maintain normothermia in the cold by modifying separate physiological traits at different time points in response to external temperature cues.
影响因子：
2.6
作者：
Buckley, Lauren B.;Khaliq, Imran;Hof, Christian
通讯作者：
Hof, Christian