高原灌丛生境下灰腹噪鹛的亲子关系

Parent-offspring relationship (POR) is one of the most important individual interactions in aminal falimy, because it illustrates how individual can optimize the tradeoff between benefits and conflicts. Although the nature of POR relies largely on the genetic relatedness of parent-offspring, the effects of environmental factors, body condition of them, the scence on which parents and offspring communicate, and whether they can recognise each other cannot be neglected. In this proposal, we will study the POR of the browncheeked laughingthrush Garrulax henrici that inhabits shrubs on the Tibetan Plateau. Based on four issues concerning kin recognition, signals used in commucation, parent-offspring cooperation and conflict, we will investigate how POR varies with environmental conditions. First, we test whether parents can identify fostered egg or nestlings by manipulation of clutch size and cross-fostering experiments. Then, we will examine the role of visual and aural signals in the communication between parents and offspring, as well as the development of acoustic signal with nestling age, by food deprivation and song playback experiments. By intruducing natual predator and stimulating provisioning and begging events, we examine how do communcating signals change parental food allocation pattern. Finally, we perform predator interference experiments and argificial feeding experiments to check the conditions under which POR switches between cooperation and conflict.

亲子关系是动物家庭中最重要的一种个体间关系，因为它最能体现个体是如何优化利益和代价权衡的。亲子关系的性质虽然很大程度上决定于亲缘度，但环境因子、亲代与子代的体况、亲子通讯场景，以及亲属识别机制存在与否的影响同样不容忽视。本项目将以青藏高原灌丛生境下的鸟类——灰腹噪鹛Garrulax henrici作为对象，从亲属识别机制、亲子通讯信号、亲子合作与亲子冲突4个主题，对其亲子关系在不同环境因子下的动态进行研究。通过卵操控和交叉培养实验来检验亲本是否具有对卵和雏鸟的识别能力；通过食物剥夺实验和声音回放实验来检验亲子间发生通讯时视觉和听觉信号的作用，以及声信号随日龄的发育情况；通过天敌引入实验、模拟递食和乞食实验来验证信号真伪对亲本递食模式的影响；最后,通过天敌干扰和人工投食实验来检测亲本和幼鸟体况的变化对亲子关系性质的影响。

按照本项目的计划，我们在灰腹噪鹛中检测了成鸟是否具备亲属识别能力以及亲子关系与环境的关系。通过一系列实验设计，我们发现灰腹噪鹛在子代在巢期间不具备对后代的识别能力。灰腹噪鹛亲鸟对卵没有识别能力，不能预判卵的孵化日期；在雏鸟4日龄以下时，亲鸟不具备判断子代是否孵出的能力；幼鸟交叉培养实验的结果表明，灰腹噪鹛亲鸟对出飞前的雏鸟不具有识别能力，不排斥义子，对不同亲缘度的雏鸟没有选择性。雏鸟被剥夺食物后，亲鸟显著提高递食率。声音回放实验证实了雏鸟可从亲鸟递食鸣叫和天敌防御时的鸣叫声信号中接收到不同的信息。灰腹噪鹛亲鸟不能区分亲生和无关雏鸟的声信号，对不同日龄的幼鸟乞食强度缺乏预判。日龄较大的雏鸟对虚假信号有一定的识别能力。在优良环境条件下，灰腹噪鹛采取雏鸟存活策略，而在恶劣条件下采取减雏策略，亲子之间的关系转变为冲突关系。在亲子关系的研究中，应当考虑到生活史不同阶段、个体差异和天敌压力的影响。