Does perceived predation risk affect patterns of extra-pair paternity? A field experiment in a passerine bird

1. Non-consumptive predator effects have been shown to influence a wide range of behavioural, life history, and morphological traits. Extra-pair reproduction is widespread among socially monogamous birds and may incur predation costs. Consequently, altered rates of extra-pair reproduction are expected in circumstances characterized by increased adult perceived predation risk. 2. Additionally, extra-pair reproduction is expected to be most affected for birds with phenotypes that generally increase predation risk (such as more active individuals). 3. In two consecutive years, perceived predation risk was manipulated for great tits, Parus major breeding in 12 nest-box plots by broadcasting sounds of their main predator (European sparrowhawk Accipiter nisus; 6 plots). As a control treatment, sounds of a sympatric, avian non-predator species were broadcasted (Eurasian blackbird, Turdus merula; 6 plots). 4. Levels of extra-pair paternity did not differ between plots with different predation-r...