DOI: 10.5061/dryad.gqnk98szq
title: Data from: Maternal investment is positively associated with the presence of extra-pair offspring in a socially monogamous songbird

description: Biparental care is common in socially monogamous avian species but, both
 partners may seek extra-pair copulations (EPCs). The relative costs and
 benefits of EPCs between the sexes are likely complex, yet the
 implications of EPCs for parental care behavior have been examined
 predominantly in males. Not only could females benefit from EPCs, but
 females would have additional information about the likelihood of
 extra-pair young (EPY) in their nest not available to their partners,
 which likely influences female behavior. We examined how the presence and
 abundance of EPY in a nest affect parental behavior in a socially
 monogamous songbird, song sparrows (Melospiza melodia). We predicted that
 females who mated outside the social pair would invest more in a clutch
 with a higher probability of EPY. We monitored nest visitation rates by
 male and female social partners as a proxy for parental investment and
 quantified extra-pair paternity in 45 nests. Maternal visitation rates
 were higher in nests with EPY compared to nests without, while males did
 not adjust their investment in relation to the presence of EPY. These
 findings support our prediction that females who participated in EPC would
 invest more in the resulting offspring.
description: # Data from: Maternal investment is positively associated with the
 presence of extra-pair offspring in a socially monogamous songbird Dataset
 DOI: [10.5061/dryad.gqnk98szq](10.5061/dryad.gqnk98szq) ## Description of
 the data and file structure The data presented here are parental care data
 in comparison to paternity status from adult and nestling wild song
 sparrows (Melospiza melodia). In socially monogamous species, individuals
 of both sexes often seek extra-pair copulation (EPCs), and there are
 likely behavioral correlates with parental investment within individuals
 that seek out EPCs, though this relationship has been examined
 predominantly in males. However, females likely benefit from EPCs, and
 have additional information about the likelihood of extra-pair young (EPY)
 in their own nest compared to their male partners and this information is
 expected to influence maternal investment. In this study, we examined how
 the presence and abundance of EPY in a nest effect the parental behavior
 of a socially monogamous songbird, song sparrows. We predicted that
 females who mated outside the social pairs would invest more in a clutch
 with a higher probability of EPY, and that males would decrease their
 investment. We monitored nest visitation rates by both male and female
 social partners for 10 days during the nestling period as a proxy for
 parental investment and quantified extra-pair paternity in 45 song sparrow
 nests. ### Files and variables #### File:
 extra-pair\_paternity\_data\_03.19.25.csv **Description:** Code and data
 files for analysis of association between extra pair young and parental
 care.  ##### Variables * pit_tag: The passive integrative transponder
 number * date: Date the behavior was recorded * visist.per.id: The
 visits/hour for that day (total number of visits /total time of care for
 that day) * nest.id: The unique nest id assigned to that nest * sex: Sex
 of parent * Number.of.SOSP.nestlings: Number of nestlings in the nest *
 total.number.nestlings: brood size * year:Year sampled *
 Cuckolding.identified.by.any.method.95.: Identification of any extra-pair
 nestlings in the nest (yes =1 or no=0) * cuck.95:Identification of any
 extra-pair nestlings in the nest (yes or no) *
 X..of.epp.offspring.in.nest: The number of extra pair young in the nest *
 X..of.offspring.sampled.that.are.epp: The portion of extra pair young in
 the nest. #### File: EPP\_Analysis\_for\_publicaiton\_final.R
 **Description:** Code and data files for analysis of association between
 extra pair young and parental care.  ## Code/software Software: R
 Statistical Software v. 4.2.2. Packages used library(Rmisc)
 library(tidyverse) library(car) library(lme4) library(lmerTest)
 library(lubridate) library(nlme) library(glmm) library(predictmeans)
 library(lsmeans) library(gridExtra) library(effects) library(emmeans)
 library(broom) library(modelr) library(ggeffects) library(ggpubr)
 library(MASS) library(performance) ## Access information Other publicly
 accessible locations of the data: * NA Data was derived from the following
 sources: * NA