Table 1. Definition of the variables considered in the analyses.

Variable	Definition
Age	Chronological age of each female (year of the breeding attempt – birth year)
YBD	Number of years before the death of the female (death year – year of the breeding attempt)
Year quality	Average number of fledglings produced by all non-cooperatively breeding females in the year of the breeding attempt
Territory quality	Average standardized territory quality of the female's resident territory, relative to all other territories
OFL present	Presence of an independent fledgling from the minor breeding season, as an indication of recent reproduction
AFR	Age of first independent breeding
ALR	Age of last independent breeding
Terminal	Binary factor categorizing each breeding attempt to be the last or not