DOI: 10.5061/dryad.f1vhhmgtb
title: Data from: Sources of variation in maternal allocation in a long-lived mammal

description: Life history theory predicts allocation of energy to reproduction varies
 with maternal age but additional maternal features may be
 important to the allocation of energy
 to reproduction. We aimed to characterize age-specific
 variation in maternal allocation and assess the relationship
 between maternal allocation and other static and dynamic maternal
 features. Mass measurements of 531 mothers and pups were used
 with Bayesian hierarchical models to explain the relationship
 between diverse maternal attributes and both the proportion of
 mass allocated by Weddell seal mothers, and the efficiency of mass
 transfer from mother to pup during lactation as well as the
 weaning mass of pups. Our results demonstrated that maternal mass
 was strongly and positively associated with the relative reserves
 allocated by a mother and a pup’s weaning mass but that
 the efficiency of mass transfer declines with maternal
 parturition mass. Birthdate was positively associated with
 proportion mass allocation and pup weaning mass, but
 mass transfer efficiency was predicted to be highest at the mean
 birthdate. The relative allocation of maternal reserves declined
 with maternal age but the efficiency of mass transfer to pups
 increases, suggestive of selective disappearance of poor-quality
 mothers. These findings highlight the importance of considering
 multiple maternal features when assessing variation in maternal
 allocation.
description: Each year since 2002, attempts were made to weigh a sample of
 mother-pup pairs at parturition, and later at 20 days after parturition
 for a mid-lactation mass and 35 days after parturition for a
 late-lactation mass. Not all mother pup pairs were available for weighing
 on target dates therefore weights were obtained 1-4 days after
 parturition, 15-25 days after parturition and 30-40 days after
 parturition. Pups were weighed using a spring scale or digital weighing
 platform and mothers were weighed using either a digital weighing
 platform, photogrammetric methods, or both (Ireland et al. 2006; Paterson
 et al. 2016). Due to the difficulty in obtaining maternal mass
 measurements with a weighing platform throughout lactation, photogrammetry
 has been used to estimate the mass of Weddell seal mothers since 2002.
 Photographs of mothers from 2002-2010 were taken using a two-dimensional
 photogrammetry technique described by Ireland et al. (2006). For
 photogrammetry data collected during 2012-2016, photographs of mothers
 were taken and analyzed using a three-dimensional photogrammetry technique
 described by de Bruyn et al. (2009). For each of the two photogrammetric
 techniques morphometric measurements were related to mass
 measurements using linear regression to obtain raw mass estimates and
 prediction errors.
description: <strong>Proportion Mass Allocation
 Model Data</strong> The
 Proportion_Mass.csv file contains data for the proportion mass allocation
 model in the following columns: speno (individual identification number),
 season (year of observation), partmass_k (raw estimated maternal
 parturition mass in kg), latemass_k (raw estimated maternal late-lactation
 mass in kg), skip (indicator variable for experienced breeder skipping
 reproduction the previous year), firstbreed (indicator variable for first
 time breeder the previous year), prebreed (indicator variable for
 prebreeder the previous year), male (indicator variable for whether the
 pup is male), part.pred.err (prediction error associated with raw
 estimated maternal parturition mass), late.pred.err (prediction error
 associated with raw estimated maternal late-lactation mass), momage.z
 (standardized maternal age), momage_quad.z (standardized and squared
 maternal age), days.z (standardized number of days between maternal
 parturtion and late-lactation mass measurements), age.first.z
 (standardized age at first reproduction), bday.z (standardized birthdate),
 bday_quad.z (standardized and squared birthdate)
 <strong>Mass Transfer Efficiency Model
 Data</strong> The
 Transfer_Efficiency.csv file contains data for the mass transfer
 efficiency model in the following columns: speno (individual
 identification number), season (year of observation), mom.partmass_k
 (raw estimated maternal parturition mass in kg), mom.midmass_k
 (raw estimated maternal mid-lactation mass in kg), mom.days (number of
 days between maternal parturition and mid-lactation mass
 measurements), skip (indicator variable for experienced breeder skipping
 reproduction the previous year), firstbreed (indicator variable for first
 time breeder the previous year), prebreed (indicator variable for
 prebreeder the previous year), male (indicator variable for whether the
 pup is male), part.pred.err (prediction error associated with raw
 estimated maternal parturition mass), mid.pred.err (prediction error
 associated with raw estimated maternal mid-lactation mass),  momage.z
 (standardized maternal age), momage_quad.z (standardized and squared
 maternal age), daily.pup.gain (standardized daily pup mass gain from
 parturition to mid-lactation), age.first.z (standardized age at first
 reproduction), bday.z (standardized birthdate), bday_quad.z (standardized
 and squared birthdate) <strong>Pup
 Weaning Mass Model Data</strong> The
 Pup_Weaning_Mass.csv file contains data for the pup weaning mass model in
 the following columns: speno (individual identification number), season
 (year of observation), mom.partmass_k (raw estimated maternal parturition
 mass in kg), pup.wean.mass (weaning mass of pups in kg), skip (indicator
 variable for experienced breeder skipping reproduction the previous year),
 firstbreed (indicator variable for first time breeder the previous year),
 prebreed (indicator variable for prebreeder the previous year), male
 (indicator variable for whether the pup is male), part.pred.err
 (prediction error associated with raw estimated maternal parturition
 mass), log.momage.z (standardized log of maternal age), pup.birth.mass.z
 (standardized pup parturition mass),  age.first.z (standardized age at
 first reproduction), bday.z (standardized birthdate), bday_quad.z
 (standardized and squared birthdate)
 <strong>*</strong> All standardized variable were
 centered using the mean and scaled by two standard deviations.