发冠卷尾的配对模式对亲代抚育和寻求婚外配权衡的影响

Parental care is a very important topic in behavioral ecology and evolutionary ecology. For species with bi-parental care, males may be confronted with an energetic and temporal trade-off between providing parental care and pursuing extra-pair matings, which is usually affected by accessible local extra-pair mating opportunities and male attractiveness. As reduced parenting effort may lead to a fitness cost of with-pair, whether males decrease parenting effort may depend on the ability of their partners to provide parental care, in other word, whether females can compensate for the reduced parental care of their partners and engage in breeding investment at a relatively high level. Therefore, it’s important to know the mating pattern of two sexes in improving our understanding of male trade-off between parenting effort and pursuing extra-pair matings. We plan to study a passerine, the hair-crested drongo (Dicrurus hottentottus), in Dongzhai National Nature reserve by using both observational and experimental methods. In this project, we investigate 1) whether the mating pattern of males offer them the possibility of decreasing parental care and seeking for extra-pair matings, and 2) whether females, who varied in the ability of providing parental care, have optical mates in terms of males attractiveness. By testing how mating patterns of two sexes shape the trade-off between parental care and pursuing extra-pair matings in males, we aim to reveal the mechanism and the evolution of this important life-history trade-off.

亲代抚育是行为生态学和进化生态学的研究热点。对于双亲抚育的物种，由于能量和时间的限制，雄性可能会面临提供亲代抚育和寻求婚外配的权衡，而且这一权衡多受到可利用的交配机会和雄性自身的性吸引力的影响。由于减少亲代抚育可能会带来婚内适合度下降的代价，雄性是否减少亲代抚育可能受其配偶亲代抚育能力的限制，即配偶是否能够补偿，进行较高水平的亲代抚育。因此了解两性的配对模式可能对查明雄性权衡亲代抚育和寻求婚外配的机制具有重要意义。本研究拟以河南董寨国家级自然保护区的雀形目鸟类——发冠卷尾（Dicrurus hottentottus）为研究对象，通过野外观察和实验相结合的方法，研究雄性的配对模式是否为其减少亲代抚育来寻求婚外配提供了条件，探讨亲代抚育能力不同的雌鸟是否有性吸引力上的最佳配偶，从而检验两性的配对模式如何影响和塑造雄性对亲代抚育和寻求婚外配的权衡，以增进对这一重要生活史权衡产生机制和进化的了解。

由于能量和时间的限制，进行双亲抚育的物种中雄性可能会面临提供亲代抚育和寻求婚外配的权衡，而且这一权衡多受到可利用的交配机会和雄性自身的性吸引力的影响。雄性减少亲代抚育可能会带来婚内适合度下降的代价，因此是否减少亲代抚育可能受雄性的配偶亲代抚育能力的限制，即配偶是否能够补偿，进行较高水平的亲代抚育。因此了解两性的配对模式可能对查明雄性权衡亲代抚育和寻求婚外配的机制具有重要意义。本项目以河南董寨国家级自然保护区的雀形目鸟类——发冠卷尾（Dicrurus hottentottus）为研究对象，以雄鸟的跗跖长为性吸引力为指标（跗跖长的个体获得婚外配的几率高），通过剪羽实验的方式操控个体的孵卵投入，研究表明与不同性吸引力的雄鸟配对的雌性个体可能并不存在亲代抚育能力上的差异，雌鸟与不同性吸引力的雄鸟配对可能对其适合度的影响较小。因此，雄性的配对模式可能并未对其减少亲代抚育来寻求婚外配提供条件，这一发现将增进对雄性权衡亲代抚育和寻求婚外配产生机制和进化的了解。