Territory configuration moderates the frequency of extra-group mating in superb fairy-wrens

The frequency of extra-pair paternity (EPP) in socially monogamous birds varies substantially between and within species, but ecological drivers of this variation remain poorly understood. Habitat configuration could influence EPP by moderating access to extra-pair mates, because species occupying territories in a clustered ‘honeycomb’ configuration have a larger pool of potential extra-group mates in their immediate neighbourhood than those living in linearly arranged territories (e.g. along narrow strips of riparian or fragmented habitat). We exploited variation in the spatial arrangement of territories due to anthropogenic modification of habitat of the cooperatively breeding superb fairy-wren Malurus cyaneus to test whether habitat configuration influenced the frequency of EPP. In this species, most paternity is obtained by males outside the social group (extra-group paternity, EGP). We found that the frequency of EGP among groups living in linear strips of roadside vegetation (41% ...

社会一夫一妻制鸟类的婚外父权（extra-pair paternity, EPP）发生频率在物种间及物种内部均存在显著差异，但该变异的生态驱动因子仍未被充分阐明。生境配置可通过调节个体对婚外配偶的可达性来影响EPP发生频率：相较于领地呈线性排列的类群（例如沿狭窄河岸带或破碎化生境分布的种群），领地呈集群状“蜂窝”布局的物种，其邻近区域内可获取的群外配偶候选池规模更大。我们借助合作繁殖的华丽细尾鹩莺（Malurus cyaneus）的生境因人为改造所产生的领地空间布局差异，开展实验以检验生境配置是否会对EPP发生频率产生影响。该物种的多数父权由社会群体外的雄性获得（即群外父权，extra-group paternity, EGP）。研究发现，栖息于路边植被线性带的种群中，EGP发生频率为41%……