Data from: Is telomere length associated with mate choice in a songbird with a high rate of extra-pair paternity?

Telomere length is related to aging in many eukaryotes and the rate of telomere attrition has been suggested to reflect individual genetic quality. Telomere length could thus have implications for mate choice. We investigated telomere length variation in bluethroat Luscinia svecica families with mixed paternity, including social parents, extra-pair fathers and nestlings, testing whether telomere length is associated with social and/or extra-pair mate choice through assortative mating or selection of mates with relatively long telomeres. In adults, relative telomere length (rTL) did not differ between the sexes, nor between two age categories. In chicks, however, rTL decreased with body mass at sampling (an index of nestling age). We found a positive correlation between the rTL of social mates, suggesting assortative mating with respect to telomere length or a correlative thereof. However, extra-pair males did not differ from social mates in rTL, and accordingly there was also no difference between within- and extra-pair young (i.e. half-siblings) when controlling for the effect of mass. We found no relationships between telomere length, age and fitness-related traits in adults, but an intriguing year-difference in telomere length in both sexes. In conclusion, we found no support for the idea that females choose extra-pair males based on their telomere length, but social mate choice seems to be influenced by rTL, possibly through its co-variation with aspects reflecting individual quality, like early arrival at the breeding grounds.

端粒长度（telomere length）与众多真核生物的衰老进程密切相关，而端粒损耗速率被认为可反映个体的遗传质量，因此端粒长度在配偶选择方面具有潜在意义。本研究针对具有混交父权的蓝喉歌鸲（Luscinia svecica）家庭开展端粒长度变异相关研究，研究对象涵盖社会双亲、额外配对父本及雏鸟，旨在检验端粒长度是否通过选型交配或选择端粒长度相对更长的配偶，与社会性配偶选择及/或额外配对配偶选择存在关联。在成年个体中，两性的相对端粒长度（relative telomere length, rTL）无显著差异，不同年龄组间亦无明显区别；但雏鸟的相对端粒长度会随采样时的体重（雏鸟年龄的替代指标）升高而降低。研究发现，社会性配偶间的相对端粒长度呈正相关，提示二者在端粒长度或其相关性状上存在选型交配现象。然而，额外配对父本与社会性配偶的相对端粒长度并无显著差异，因此在控制体重效应后，婚内后代与额外配对后代（即半同胞）之间也未出现显著差异。本研究未发现成年个体的端粒长度、年龄与适合度相关性状之间存在关联，但两性的端粒长度均存在引人关注的年度差异。综上，本研究未发现雌性基于端粒长度选择额外配对雄鸟的证据，但社会性配偶选择似乎受相对端粒长度的影响，这可能是由于相对端粒长度与反映个体质量的特征（如较早抵达繁殖地）存在共变关系。