Data from: The relationship between plumage colouration, problem-solving and learning performance in great tits Parus major

Recent studies suggest that individuals with better problem-solving and/or learning performance have greater reproductive success, and that individuals may thus benefit from choosing mates based on these performances. However, directly assessing these performances in candidate mates could be difficult. Instead, the use of indirect cues related to problem-solving and/or learning performance, such as condition-dependent phenotypic traits, might be favored. We investigated whether problem-solving and learning performance on a novel non-foraging task correlated with sexually selected plumage colouration in a natural population of great tits Parus major. We found that males successful in solving the task had darker blue-black crowns than non-solvers, and that males solving the task more rapidly over multiple attempts (i.e. learners) exhibited blue-black crowns with higher UV chroma and shorter-wavelength hues than non-learners. In contrast, we found no link between behavioural performance on the task and the yellow breast colouration in either sex. Our findings suggest that blue-black crown colouration could serve as a signal of problem-solving and learning performance in wild great tit males. Further research remains necessary to determine whether different sexually selected traits are used to signal cognitive performance for mate choice, either directly (i.e. cognitive performance influencing individual’s health and ornamentation through diet for example) or indirectly (i.e. due to a correlation with a third factor such as individual quality or condition).

近期研究表明，具备更优问题解决能力与/或学习能力的个体，其繁殖成功率更高；因此，择偶时参考此类认知表现或可使个体获益。然而，直接评估候选配偶的此类认知表现往往难度颇高。相较之下，利用与问题解决能力、学习能力相关的间接线索——例如依赖个体状态的表型性状——或为更优选择。本研究以自然种群中的大山雀（Parus major）为研究对象，探究其在一项新型非觅食任务中的问题解决与学习表现，是否与性选择塑造的羽色特征存在关联。研究结果显示：成功完成该任务的雄性大山雀，其头顶蓝黑色羽色较未完成任务者更深；而在多次尝试中更快完成任务的雄性（即学习者），其头顶蓝黑色羽色的紫外色度更高、波长更短，与非学习者存在显著差异。与之相反，本研究未发现该任务中的行为表现与两性的黄色胸羽颜色存在任何关联。上述研究结果表明，野生雄性大山雀的蓝黑色头顶羽色，或可作为其问题解决与学习能力的信号指标。未来仍需开展进一步研究，以明确择偶过程中是否存在不同的性选择性状用于传递认知能力信号：既可能是认知能力通过饮食等途径直接影响个体健康与装饰性状，也可能是认知能力与个体质量、状态等第三方因素存在关联，从而间接传递此类信号。