Variance in mating systems can only be understood if the fitness consequences of the available options are known for both sexes. In Pied Flycatchers Ficedula hypoleuca it has for long been suggested that females pairing with already mated males pay a fitness cost, and it is still debated why females do not always choose an unmated male, The supposed fitness cost of mating secondarily is based on very incomplete fitness measures, which not includes important factors as the survival of females and young to the next breeding season. In this paper I show that secondary Pied Flycatcher females do not pay a survival cost. The number of recruits for a given laying date is not lower for early breeding secondary females compared with monogamous females, but late laying secondary females have fewer recruits. However, this result of mating status on the number of recruits depends on how to define secondary broods. If nests are included in which no male was caught, the secondary broods have a lower recruit number irrespective of laying date. Composite fitness measures including both recruit number and female survival do not show a statistically significant fitness cost between females that pair either monogamously or with an already mated male at the same day of the season, but the average reduction is about 15%. These data show that a more complete fitness measure including survival of adults and juveniles does not lead to a higher estimated cost of pairing with an already paired male. [KEYWORDS: Ficedula hypoleuca, survival, reproduction, mating system, polygyny]
Original languageEnglish
Journal publication date2002

ID: 207065