Sex differences in nest attention against simulated conspecific intrusions in the Saffron Finch ( Sicalis flaveola pelzelni )

Nest attention has a strong effect on nestling survival and is essential for the reproductive success of the parents. Secondary cavity nesters compete intensively for access to cavities and face high risk of nest usurpation by conspecifics. We describe nest attention by both sexes in the Saffron Finch (<em>Sicalis flaveola pelzelni</em>), and compare rates of nest attention in response to experimental territorial intrusions of live male and female conspecifics. During the incubation and brooding periods, in response to intrusions by other females or males, both natural and experimental, the attending females arrived at the nest immediately. Females also stayed close to the nest during egg laying and “old” 8–9 days old nestlings’ periods, but never attacked the intruders. Attending males took more time to approach the nest but spent a lot of time close to it, during the egg laying, incubation, and “young” 4–5 days old nestling periods, especially during simulated intrusions by other males. Focal males kept intruders of both sexes at bay and physically attacked the male intruders. The observed responses could be elicited by the perceived risk of mate or cavity loss before raising a brood. This study on a multi-brooded subtropical obligate secondary cavity nester reveals sex differences of nest attention in response to the sex of conspecific intruders.