Individual quality and phenology mediate the effect of radioactive contamination on body temperature in Chernobyl barn swallows

Anthropogenic stressors, such as radioactive contaminants released from the Chernobyl and Fukushima Daiichi accidents, deteriorate ecological and evolutionary processes, as evidence for damaging effects of radioactive contamination on wildlife are accumulating. Yet little is known about physiological traits of animals inhabiting contaminated areas, and how those are affected by individual quality and phenology. We investigated variation in body temperature of wild barn swallows, <i>Hirundo rustica,</i> exposed to radioactive contamination from the Chernobyl accident in Ukraine and Belarus. We tested whether exposure to variable levels of radioactive contamination modified core body temperature of birds, and whether individual and phenological characteristics modulated radiosensitivity of body temperature. We showed that barn swallow body temperature varied with exposure to environmental radioactive contamination and that individual characteristics and phenology affected radioactive exposure. Increased radiosensitivity and up-regulation of body temperature was detected in birds of low body condition, high risk of capture, and in animals captured late during the day but early during the season. These results highlight the complex ways that the body temperature of a wild bird is impacted by exposure to increased radioactive contamination in natural habitats. By impacting body temperature, increased radioactive contamination may compromise energetic balance, jeopardize responsiveness to global warming and increase risk of overheating. p { margin-bottom: 0.1in; direction: ltr; color: #000000; line-height: 115%; orphans: 2; widows: 2; background: transparent }p.western { font-family: "Liberation Serif", "Times New Roman", serif; font-size: 12pt; so-language: en-US }p.cjk { font-family: "Noto Sans CJK SC"; font-size: 12pt; so-language: zh-CN }p.ctl { font-family: "Lohit Devanagari", "Calibri"; font-size: 12pt; so-language: hi-IN }a:link { color: #000080; text-decoration: underline }a.ctl:link { so-language: zxx }

人为胁迫因子（anthropogenic stressors），例如切尔诺贝利与福岛第一核事故泄漏的放射性污染物，正不断破坏生态与演化进程——目前已有越来越多证据表明放射性污染对野生生物具有破坏性影响。然而，学界对栖息于污染区域的动物的生理特征，以及这些特征如何受个体素质与物候（phenology）影响的了解仍十分有限。

我们针对栖息于乌克兰与白俄罗斯境内受切尔诺贝利核事故放射性污染区域的野生家燕（*Hirundo rustica*）的体温变异规律展开研究。本研究旨在验证两项科学假设：其一，不同水平的放射性污染暴露是否会改变鸟类的核心体温；其二，个体与物候特征是否会调节体温的辐射敏感性（radiosensitivity）。

研究结果显示，家燕的体温随环境放射性污染暴露水平发生显著变化，且个体特征与物候会影响其放射性暴露程度。我们发现，体况较差、捕获风险较高的个体，以及当日捕获时段较晚但季内捕获时间较早的个体，其体温辐射敏感性更高，且体温上调幅度更为显著。

上述研究结果揭示了自然栖息地中，野生鸟类体温受放射性污染暴露水平升高影响的复杂机制。放射性污染水平升高可通过干扰体温稳态，破坏动物的能量平衡，削弱其对全球变暖的响应能力，并进一步增加过热风险。