Data from: Maternal presence facilitates plasticity in offspring behavior: insights into the evolution of care

Fundamental to the definition of parental care is that care confers benefits to the offspring. However, the mechanisms resulting in these benefits remain poorly understood, particularly in species where postnatal care is not obligatory. Here, we address this shortcoming using a lizard, Liopholis whitii, in which family life is facultative and relatively simple – extending to prolonged associations between parents and offspring within the parental territory. Using a split-clutch design, we housed offspring either with their mother or alone during the first eight weeks of postnatal life and examined whether maternal presence affected (i) the expression of key functional behaviors, and (ii) learning ability in a biologically relevant anti-predatory task. We found that offspring housed with their mothers expressed heightened levels of activity, boldness and exploration compared to offspring who were housed alone. Furthermore, we show that associating with mothers during early postnatal periods led to improved offspring performance in the anti-predation learning task. Together these results suggest that even relatively simple forms of enhanced parent-offspring association can have significant impacts on offspring traits. We argue that such effects may help refine and stabilize parent-offspring associations early in their evolution, potentially setting the stage for the elaboration of both parent and offspring behaviors.

亲本照料（parental care）的核心界定标准在于，该行为可为子代（offspring）带来收益。然而，催生这些收益的具体机制仍有待阐明，尤其针对那些产后照料并非必需的物种而言。本研究以白氏石龙子（Liopholis whitii）为研究对象，该物种的家庭生活模式为兼性形式且结构相对简单，仅表现为亲本领地内亲本与子代间的长期共处关系。本研究采用分窝实验设计，将子代在产后前8周分为两组：一组与母本共同饲养，另一组单独饲养；并以此检验母本存在与否是否会影响（1）关键功能行为的表达，以及（2）在具有生态相关性的反捕食任务中的学习能力。研究结果显示，与母本共同饲养的子代，其活动量、大胆性与探索行为的表达水平均显著高于单独饲养的子代。此外，本研究证实，产后早期与母本共处可提升子代在反捕食学习任务中的表现。综合上述结果可见，即便是形式相对简单的亲子伴生关系强化，也可对子代性状产生显著影响。我们认为，此类效应或可在演化早期助力优化并稳定亲子伴生关系，为亲本与子代行为的精细化演化奠定基础。