Socially monogamous male birds are predicted to maximise their reproductive success by pursuing extra-pair copulations (EPCs) while engaging in anti-cuckoldry behaviour such as mate guarding. In the stitchbird, Notiomystis cincta, high levels of forced EPCs and a high proportion of nestlings resulting from extra- pair fertilisations lead to the prediction that males of this species should exhibit intense paternity guarding behaviours.
Winter is a challenging time for temperate insectivorous songbirds, due to colder temperatures, reduced prey activity and shorter diurnal foraging times. For species that are non-migratory, territorial and monogamous, winter conditions may result in within-pair competition. However, little is known about how monogamous pairs coexist on their winter territories. We investigated temporal patterns in male–female interactions of the New Zealand robin (Petroica australis to better understand mechanisms of coexistence during winter.