Data from: Demographic mechanisms of inbreeding adjustment through extra-pair reproduction

We used comprehensive pedigree and pairing data from free-living song sparrows (Melospiza melodia) to quantify these three processes and hence investigate how individual females could adjust mean offspring f through instantaneously random extra-pair reproduction. 4. Female song sparrows tended to form social pairings with unrelated or distantly related males slightly less frequently than expected given random pairing within the defined set of available males.

Furthermore, social pairings between more closely related mates tended to be more likely to persist across years than social pairings between less closely related mates. However, these effects were small and the mean relatedness between females and their sets of potential extra-pair males did not change substantially across the years through which social pairings persisted. 5. Our framework and analyses illustrate how demographic and social structuring within populations might allow females to adjust mean f of offspring through random extra-pair reproduction without necessarily requiring explicit kin discrimination, implying that adjustment of offspring f might be an inevitable consequence of extra-pair reproduction.

New theoretical and empirical studies are required to explore the general magnitude of such effects and quantify the degree to which they could facilitate or constrain long-term evolution of extra-pair reproduction.

Usage notes

PairsData_Dryad This file contains data required for the basic descriptive analysis of social pairing in relation to kinship. NewMalesPairings_Dryad This file contains data required for the analysis of social pairing in relation to kinship between females and the 'new males' set of potential mates. AllMalesPairings_Dryad This file contains data required for the analysis of social pairing in relation to kinship between females and the 'all males' set of potential mates.

PairPersistence_Dryad This file contains data required for the analysis of social pair persistence in relation to kinship. ChangeMeanK_Dryad This file contains data required for the analysis of changing mean kinship within the duration of females' social pairings.