School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China.
Administration Bureau of Dongzhai National Nature Reserve, Luoshan, Henan, China.
Oecologia. 2024 Jun;205(2):339-350. doi: 10.1007/s00442-024-05577-0. Epub 2024 Jun 3.
Knowledge of the effect of harsh weather on the phenotypic traits of organisms is essential for understanding the environmental influence on phenotype evolution and holds implications for predicting how species respond to current climate change. For many birds, harsh weather in winter often imposes a strong selective effect on their survival, and only the individuals with certain phenotypes may survive. However, whether the selective effect on phenotype varies with winter weather conditions has been poorly investigated. Here, we explored the selective effect of winter weather on black-throated tit's (Aegithalos concinnus) morphological traits under winters with and without severe snowstorms. We found that for males, the sizes of their bills, heads and wings significantly affected their overwinter survival, but the effects varied with winter conditions. In relatively benign winters, males with smaller bill depths, smaller bill surface areas, and greater head lengths survived better; whereas, in winters with severe snowstorms, a reverse pattern was found. This phenomenon was likely driven by selection pressures from heat retention and foraging requirements, with their relative importance depending on winter conditions. Additionally, wing length was positively correlated with male survival and the relationship was stronger in harsher winters, which was probably due to longer wings' higher flight efficiency in adverse weather. By contrast, we found no correlation between morphological traits and survival in females. These results suggest a sex-specific and condition-dependent selective effect of environment on bird phenotypes, implying complicated interactions between different selection pressures and phenotype evolution.
了解恶劣天气对生物表型特征的影响对于理解环境对表型进化的影响至关重要，并且对于预测物种如何应对当前的气候变化具有重要意义。对于许多鸟类来说，冬季恶劣的天气常常对它们的生存产生强烈的选择作用，只有具有某些表型的个体才能生存下来。然而，冬季天气条件对表型的选择作用是否存在差异，这一问题还没有得到充分的研究。在这里，我们探讨了冬季是否有严重暴风雪对黑喉山雀（Aegithalos concinnus）形态特征的选择作用。我们发现，对于雄性来说，它们的喙、头部和翅膀的大小显著影响它们的越冬生存，但这种影响因冬季条件而异。在相对温和的冬季，喙深度较小、喙表面积较小和头部较长的雄性生存得更好；而在有严重暴风雪的冬季，则出现了相反的模式。这种现象可能是由热保留和觅食需求的选择压力驱动的，其相对重要性取决于冬季条件。此外，翼长与雄性的生存呈正相关，而在恶劣的冬季这种相关性更强，这可能是由于在恶劣天气下长翅膀具有更高的飞行效率。相比之下，我们在雌性中没有发现形态特征与生存之间的相关性。这些结果表明，环境对鸟类表型的选择作用具有性别特异性和条件依赖性，暗示着不同选择压力和表型进化之间存在复杂的相互作用。
