Exposure to predator models during the fertile period leads to higher levels of extra-pair paternity in blue tits

1) The perceived risk of predation can affect breeding behaviour and reduce reproductive success in prey species. Individuals exposed to predators may also adopt different mating tactics with potential consequences for the distribution of paternity in socially monogamous species that engage in extra-pair copulations. 2) We experimentally increased perceived predation risk during the fertile period in blue tits Cyanistes caeruleus. Every morning between nest completion and the onset of egg laying, we presented a model of either a predator or a non-predator (control) near active nestboxes. 3) Broods from pairs exposed to predators had higher levels of extra-pair paternity than control broods. This mainly resulted from a higher proportion of extra-pair offspring in broods with at least one extra-pair young. 4) Females exposed to predators first emerged from the nestbox later in the morning, stayed away from the nestbox for longer and were less likely to be visited at the nest by their soci...