Effects of mating system, kinship, and environment on complex joint-nesting breeding birds

目前，关于一夫一妻制和相关的亲属关系是否是合作进化的关键因素，存在着激烈的争论。当幼崽的分散被推迟时，一夫一妻制会导致高度的亲属关系（允许利他行为和合作繁殖的亲属选择）。然而，延迟的分散也导致了与已知群体成员的稳定的社会互动（允许互惠的帮助行为，这可能提供直接的适应性）。大多数关于合作繁殖者的研究都集中在一夫一妻制的基于亲属的合作群体上，从而混淆了交配制度和合作。我研究了两个物种，其中一夫一妻制和基于亲属的合作繁殖是不相关的。我的研究项目的长期目标是确定群体内的亲属关系、交配制度和社会稳定如何影响群体繁殖鸟类的合作和冲突。******我们研究了两种公共联合筑巢鸟类，它们是一种群居繁殖的鸟类，包括多只繁殖雄性和雌性，它们在一个共同的巢中集体产卵以产生联合蛋。扁嘴anis （Crotophaga ani; Cuculidae）生活在一夫一妻制的非近亲群体中。扁虱（Porphyrio melanotus melanotus；黑虱科）通常生活在近亲群体中，一夫多妻制繁殖，多个雄性和雌性繁殖者相互交配，没有配对关系。******我将在这项资助的过程中解决三个主要问题。第一个问题：公共联合筑巢的适应性结果是什么？在项目1和项目2中，我们将研究在非亲缘寄生系统中合作繁殖的直接适应度效益。在pukeko的项目3中，我们将检验两个雌性亲属同步产卵比一个优势雌性单独产卵更能提高包容性适合度的假设。******第二个问题：在共同的亲属群体中，个体是否会偏爱自己的后代后代而不是非后代后代，如果是这样的话，是什么适应导致了这种偏爱？在项目4中，我们将检验这样一个假设，即即使在亲缘选择系统中，雌性白斑猕猴繁殖者也会对自己的后代表现出母性偏爱。******第三个问题：在合作繁殖物种中，优势雌性是如何调节从属雌性的繁殖的？北岛（新西兰）的扁虱种群全年生活在稳定的亲缘群体中，从属的雌性表现出较低的繁殖水平。相比之下，南岛的非亲属群体生活在季节性领地（一年中的部分时间；不太稳定），从属的雌性没有表现出繁殖水平的下降。在项目5中，我们将使用雌性迁移实验来验证在永久领地上稳定联合筑巢群体中的优势雌性调节下属繁殖的假设。**

Currently there is great debate about whether monogamy and associated kinship is a key element in the evolution of cooperation. Monogamy leads to high levels of kinship when dispersal of young is delayed (allowing kin selection for altruistic behaviour and cooperative breeding). However, delayed dispersal also leads to stable social interactions with known group members (allowing reciprocation of helpful behaviours which may provide direct fitness). Most studies of cooperative breeders focus on monogamous kin-based cooperative groups, thus confounding mating system and cooperation. I study two species in which monogamy and kin-based cooperative breeding are not correlated. The long-term goal of my research program is to determine how kinship, mating system, and social stability within groups affect cooperation and conflict in group breeding birds.******We study two species of communal joint-nesting birds birds that breed in groups including multiple breeding males and females that collectively lay eggs to produce a joint-clutch in single shared nest. Smooth-billed anis (Crotophaga ani; Cuculidae) live in non-kin groups of monogamous pairs. Pukeko (Porphyrio melanotus melanotus; Rallidae) usually live in close kin groups and breed polygynandrously multiple male and female breeders mate with each other without pair bonds. ******I will address three main questions over the course of this grant. First Question: What are the fitness consequences of communal joint-nesting? In projects 1 and 2 with anis we will examine direct fitness benefits of cooperative breeding in a non-kin parasitic system. In project 3 with pukeko, we will test the hypothesis that the laying of synchronized joint clutches by two female kin improves inclusive fitness compared with extended laying by a dominant female alone. ******Second Question: Do individuals favour their descendent young over non-descendent young in communal kin groups, and if so what adaptations underlie such favoritism? In project 4 we will test the hypothesis that female pukeko breeders show maternal favouritism towards their own young even within a kin selected system. ******Third Question: How is subordinate female reproduction modulated by dominant females in cooperative breeding species? North Island (New Zealand) populations of pukeko live in stable kin groups on year-round territories and subordinate females show reduced levels of reproduction. In contrast, South Island non-kin groups live in seasonal territories (held part of the year; less stable) and subordinate females do not show reduced levels of reproduction. In project 5 we will use female removal experiments to test the hypothesis that dominant females in stable joint-nesting groups on permanent territories modulate reproduction by subordinates. **