Data from: Population properties affect inbreeding avoidance in moose

Mechanisms reducing inbreeding are thought to have evolved owing to fitness costs of breeding with close relatives. In small and isolated populations, or populations with skewed age- or sex distributions, mate choice becomes limited, and inbreeding avoidance mechanisms ineffective. We used a unique individual-based dataset on moose from a small island in Norway to assess whether inbreeding avoidance was related to population structure and size, expecting inbreeding avoidance to be greater in years with larger populations and even adult sex ratios. The probability that a potential mating event was realized was negatively related to the inbreeding coefficient of the potential offspring, with a stronger relationship in years with a higher proportion or number of males in the population. Thus, adult sex ratio and population size affect the degree of inbreeding avoidance. Consequently, conservation managers should aim for sex ratios that facilitate inbreeding avoidance, especially in small and isolated populations.

近亲繁殖会带来适合度代价，学界普遍认为，用以减少近交的相关机制正是在此压力下演化形成的。在小型隔离种群，或是年龄结构、性比存在偏倚的种群中，配偶选择会受到限制，近交规避机制也难以发挥作用。我们借助挪威某小岛的独特驼鹿基于个体的数据集（individual-based dataset），探究近交规避行为是否与种群结构及种群规模相关，并提出研究假设：在种群规模更大、成年性比更均衡的年份，近交规避程度会更高。潜在交配事件得以发生的概率，与潜在后代的近交系数（inbreeding coefficient）呈显著负相关；且在种群雄性占比更高或雄性数量更多的年份，这种负相关关系更为强烈。由此可见，成年性比与种群规模会对近交规避的程度产生影响。因此，保育管理者应着力构建利于近交规避的性比结构，针对小型隔离种群尤需如此。