Data from: Age and sex affect quantitative genetic parameters for dominance rank and aggression in free-living greylag geese

Knowledge of the genetic and environmental influences on a character is pivotal for understanding evolutionary changes in quantitative traits in natural populations. Dominance and aggression are ubiquitous traits that are selectively advantageous in many animal societies and have the potential to impact the evolutionary trajectory of animal populations. Here we provide age- and sex-specific estimates of additive genetic and environmental components of variance for dominance rank and aggression rate in a free-living, human-habituated bird population subject to natural selection. We use a long-term data set on individually marked greylag geese (Anser anser) and show that phenotypic variation in dominance-related behaviours contains significant additive genetic variance, parental effects and permanent environment effects. The relative importance of these variance components varied between age and sex classes, whereby the most pronounced differences concerned non-genetic components. In particular, parental effects were larger in juveniles of both sexes than in adults. In paired adults, the partner's identity had a larger influence on male dominance rank and aggression rate than in females. In sex- and age-specific estimates, heritabilities did not differ significantly between age and sex classes. Adult dominance rank was only weakly genetically correlated between the sexes, leading to considerably higher heritabilities in sex-specific estimates than across sexes. We discuss these patterns in relation to selection acting on dominance rank and aggression in different life history stages and sexes and suggest that different adaptive optima could be a mechanism for maintaining genetic variation in dominance-related traits in free-living animal populations.

阐明性状所受遗传与环境影响，对解析自然种群中数量性状的进化改变至关重要。支配行为与攻击性是诸多动物社群中普遍存在的性状，这类性状往往具有选择优势，并可能影响动物种群的进化轨迹。本研究针对一处经受自然选择、习惯人类接触的野生鸟类种群，提供了支配等级（dominance rank）与攻击速率（aggression rate）的年龄、性别特异性加性遗传方差（additive genetic variance）及环境方差组分估算值。我们依托长期监测的个体标记灰雁（Anser anser）数据集开展研究，结果显示：与支配行为相关的表型变异（phenotypic variation）中，存在显著的加性遗传方差、亲本效应（parental effects）与永久环境效应（permanent environment effects）。上述方差组分的相对重要性随年龄与性别类群存在差异，其中最显著的差异体现在非遗传组分上。具体而言，两性幼体的亲本效应均强于成体。在配对的成体中，配偶身份对雄性支配等级与攻击速率的影响大于雌性。按性别与年龄分层的估算结果显示，不同年龄、性别类群间的遗传力（heritabilities）并无显著差异。两性间成体支配等级的遗传相关性较弱，这使得按性别分层的估算中，遗传力显著高于不分性别的整体估算结果。我们结合不同生活史阶段与性别下作用于支配等级与攻击性的选择压力，对上述结果模式展开讨论，并提出：不同的适应性最优值，或许是维持野生动物种群中支配相关性状遗传变异的潜在机制。