Digest: Extra‐pair mating and inbreeding avoidance in a socially monogamous fairy‐wren*

Infidelity in socially monogamous birds may be a mechanism of inbreeding avoidance and may be impacted by cooperative breeding. Hajduk et al. (2018) find that relatedness increases extra‐pair mating only in mother‐son social pairs of Malurus cyaneus, while a greater number of nest helpers consistently increases the proportion of extra‐pair offspring. These findings suggest that there may be multiple explanations for extra‐pair mating within a single population.