Cost, risk, and avoidance of inbreeding in a cooperatively breeding bird.

摘要: Inbreeding is often avoided in natural populations by passive processes such as sex-biased dispersal. But, many social animals, opposite-sexed adult relatives are spatially clustered, generating a risk of incest and hence selection for active inbreeding avoidance. Here we show that, long-tailed tits (Aegithalos caudatus), cooperative breeder that risks living alongside opposite-sex relatives, carries fitness costs kin discrimination during mate choice. First, identified positive association between heterozygosity fitness, indicating costly. We then compared relatedness within breeding pairs to expected under multiple mate-choice models, finding pair consistent with avoidance first-order partners. Finally, the similarity vocal cues offers plausible mechanism against Long-tailed known discriminate calls close nonkin, they favor contexts, so conclude use same rule avoid do direct help toward kin.