Co-operation, conflict and the coordination of care in a social bird

父母通常会合作照顾子女，但由于父母的自私利益不同，双方在照顾子女数量上的性冲突是不可避免的。由此产生的雄性和雌性之间的“投资游戏”已经在双亲抚养的物种中进行了广泛的探索，但在合作繁殖系统中，这种游戏变得更加复杂，在这种系统中，父母由帮手照顾孩子。这种系统中的投资游戏在父母和帮助者提供的相对照顾量方面具有高度可变的结果（Green et al. 2016）。最重要的是，在双亲或合作繁殖系统中，照顾者协商每个参与者的最佳投资的机制很少受到关注。该项目将研究合作繁殖的长尾山雀（Aegithalos caudatus）的父母和助手如何协调照顾后代，以解决冲突并最大限度地提高个体适应性。该项目将利用对长尾山雀长达25年的亲代照料和适应性研究数据，结合实地观察和实验，以及投资模式的统计建模，实现以下目标：确定父母和帮助者是否通过协调访巢来协商照顾事宜2。目的：确定照顾协调的变异性对后代状况和生存的影响。进行实地观察和实验，以确定影响父母和帮助者护理协调的直接因素本项目将检查父母和帮助者之间的护理模式，测试从最近关于协调变化的原因和后果的理论研究中得出的多种假设。该学生将研究谢菲尔德附近一个单独标记的长尾山雀种群，该种群已经有一个详细的供应行为数据库。学生还将进行新颖的实地实验，并开发统计模型来检验假设。该项目以最近对长尾山雀的投资游戏（Adams et al. 2015）和双亲代照料协调（Bebbington & Hatchwell 2016）的研究为基础，并将补充研究地点对该物种的持续研究。

Parents often cooperate to care for offspring, but sexual conflict over the amount of care that each provides is inevitable because the selfish interests of parents differ. The resulting 'investment game' between males and females has been explored extensively in species with biparental care, but this game becomes far more complex in cooperative breeding systems where parents are assisted by helpers in caring for young. Investment games in such systems have a highly variable outcome in terms of the relative amounts of care provided by parents and helpers (Green et al. 2016). Most importantly, the mechanism through which carers negotiate the optimal investment of each player has received little attention in either biparental or cooperative breeding systems. This project will investigate how parents and helpers in a cooperatively breeding bird, the long-tailed tit Aegithalos caudatus, coordinate their care for offspring in order to resolve conflicts and maximize individual fitness.The studentship will use data on parental care and fitness from a 25-year study of long-tailed tits, coupled with field observations and experiments, and statistical modeling of investment patterns to achieve the following objectives:1. To determine whether parents and helpers negotiate care through the coordination of visits to nests2. To determine the effect of variability in the coordination of care on offspring condition and survival3. To conduct field observations and experiments to determine the proximate factors affecting coordination of care by parents and helpersThis project will examine patterns of care among parents and helpers, testing multiple hypotheses derived from recent theoretical studies on the causes and consequences of variation in coordination. The student will work on an individually marked population of long-tailed tits near Sheffield for which a detailed database on provisioning behaviour already exists. The student will also conduct novel field experiments and develop statistical models to test hypotheses. This project leads on from recent studies of investment games (Adams et al. 2015) and biparental coordination of care (Bebbington & Hatchwell 2016) in long-tailed tits, and will complement ongoing studies of this species at the study site.