Figure 1

Schematic representation of the nest manipulation treatments applied in the study, with reference to age classification. In “Early parasitism” an experimental parasitic egg was placed into a complete but empty nest, and monitored for ejection, desertion or acceptance (and removed if still present on the day before “Late parasitism” started); in “Late parasitism” one host egg was exchanged with an experimental parasitic egg on the day when the natural clutch size reached 5 eggs and the nest was monitored for ejection, desertion or acceptance for 5 days.