A nest was defined as reproductively active once an egg had been laid. A nest was classified as successful
if at least one young fledged, and failed if it had been active but subsequently did not produce
at least one fledgling. Laying, hatching and fledging dates were based on nest observations and nest
checks. Fledging rate was defined as the number of fledglings produced per active nest (fledgling
nest -1 ), whereas nest success was the proportion of active nest attempts that fledged at least one
young. Hatching success was defined as the percentage of eggs to hatch successfully from a nest and
fledgling success as the percentage of nestlings to successfully fledge from a nest. Incubation and
brooding refer to when an adult was physically sitting on the eggs or the nestlings. We defined nest
attendance as when an adult was physically present at the nest during the nestling stage.