Data from: An experimental test of the relationship between yolk testosterone and the social environment in a colonial passerine

Maternal hormones can be transferred to offspring during prenatal development in response to the maternal social environment, and may adaptively alter offspring phenotype. For example, numerous avian studies show that aggressive competition with conspecifics tends to result in females allocating more testosterone to their egg yolks, and this may cause offspring to have more competitive phenotypes. However, deviations from this pattern of maternal testosterone allocation are found, largely in studies of colonial species, and have yet to be explained. Colonial species may have different life-history constraints causing different yolk testosterone allocation strategies in response to conspecific competition, but few studies have experimentally tested whether colonial species do indeed differ from that of solitary species. To test this, we collected eggs from zebra finches (Taeniopygia guttata), a colonial species, in the presence and absence of conspecific intrusions. Females did not alter the concentration of testosterone deposited in eggs laid during intrusions despite becoming more aggressive. These results suggest that maternal effects are not characterized by a uniform response to the social environment, but rather need to be contextualized with life-history traits.母体激素可响应母体社交环境，在产前发育阶段传递给子代，并可适应性地改变子代表型。例如，众多鸟类研究表明，与同种个体的攻击性竞争往往会促使雌性向卵黄中分配更多睾酮，这可能使子代表现出更强的竞争性表型。然而，此类母体睾酮分配模式的偏离现象多发现于集群物种的相关研究中，目前尚未得到合理解释。集群物种可能存在不同的生活史限制，使其在应对同种竞争时采取差异化的卵黄睾酮分配策略，但目前鲜有实验研究验证集群物种确实与独居物种存在此类差异。为验证这一假设，我们在存在与不存在同种个体入侵的两种情境下，收集了集群繁殖物种斑胸草雀（Taeniopygia guttata）的卵。尽管雌性在入侵情境下攻击性增强，但并未改变入侵期所产卵的睾酮沉积浓度。上述结果表明，母体效应并非对社交环境呈现统一的响应模式，而是需要结合生活史特征进行具体分析。