DOI: 10.5061/dryad.1j25j
title: Data from: Double decomposition: decomposing the variance in subcomponents of male extra-pair reproductive success

description: 1. Extra-pair reproductive success (EPRS) is a key component of male
 fitness in socially monogamous systems and could cause selection on female
 extra-pair reproduction if extra-pair offspring (EPO) inherit high value
 for EPRS from their successful extra-pair fathers. However, EPRS is itself
 a composite trait that can be fully decomposed into subcomponents of
 variation, each of which can be further decomposed into genetic and
 environmental variances. However, such decompositions have not been
 implemented in wild populations, impeding evolutionary inference. 2. We
 first show that EPRS can be decomposed into the product of three
 life-history subcomponents: the number of broods available to a focal male
 to sire EPO, the male's probability of siring an EPO in an available
 brood and the number of offspring in available broods. This decomposition
 of EPRS facilitates estimation from field data because all subcomponents
 can be quantified from paternity data without need to quantify extra-pair
 matings. Our decomposition also highlights that the number of available
 broods, and hence population structure and demography, might contribute
 substantially to variance in male EPRS and fitness. 3. We then used 20
 years of complete genetic paternity and pedigree data from wild song
 sparrows (Melospiza melodia) to partition variance in each of the three
 subcomponents of EPRS, and thereby estimate their additive genetic
 variance and heritability conditioned on effects of male coefficient of
 inbreeding, age and social status. 4. All three subcomponents of EPRS
 showed some degree of within-male repeatability, reflecting combined
 permanent environmental and genetic effects. Number of available broods
 and offspring per brood showed low additive genetic variances. The
 estimated additive genetic variance in extra-pair siring probability was
 larger, although the 95% credible interval still converged towards zero.
 Siring probability also showed inbreeding depression and increased with
 male age, while the numbers of available broods and offspring per brood
 did not. 5. Our results indicate that the probability that a male will
 sire an EPO in an available brood is the primary source of genetic
 variation in male EPRS, implying that the evolution of female extra-pair
 reproduction could be facilitated by genetic covariance with this
 subcomponent of EPRS.
description: Phenotypic data: number
 of available broodsThis file contains the
 phenotypic data for the univariate quantitative genetic analyses of the
 number of available broods (Nbroods).Nbrood.dryad.txtPhenotypic data: Psire and number of available offspringPhenotypic data for the univariate quantitative genetic analyses of the probability that an offspring within an available brood (or litter) will be sired as an EPO by a focal male (Psire) and the number of available offspring.Psire.dryad.txtPedigree for Psire, Nbroods, and number of offspringThis file contains the non-zero elements of the inverted A (relationship) matrix data for the animal model analyses of Psire, Nbroods, and number of offspring.pedigree1_dryad.txtPedigree for analysis of Pat.successThis file contains the non-zero elements of the inverted A (relationship) matrix data for the animal model analysis of Pat.success.pedigree2_dryad.txtPhenotypic data: Ppat.successThis file contains the phenotypic data for the univariate quantitative genetic analyses of the probability that an offspring within an available brood (or litter) will be sired as an additional EPO by a focal male given that he sired one EPO in that brood (Ppat.success).Ppat.dryad.txt