DOI: 10.5061/dryad.j6q573nv5
title: The ecology of gestational growth in a wild cooperative mammal

description: In wild mammals, early postnatal growth strongly affects offspring
 survival and fitness, but little is known about the causes and
 consequences of variation in prenatal growth. We investigated whether
 gestational weight gains vary according to maternal traits and social and
 environmental conditions, and how prenatal growth affects the fates of the
 resulting offspring, using an exceptionally large sample of repeated
 pregnant body weight records from individually recognisable wild meerkats
 (Suricata suricatta). Pregnant meerkats’ body weights remained stable
 during the first half of gestation and then increased linearly until they
 gave birth. Gestational weight gains were more rapid under favourable
 environmental conditions and when mothers were experimentally
 food-supplemented, suggesting that nutrition strongly determines prenatal
 growth. While social conditions and reproductive competition shape
 postnatal growth in many social vertebrates (including meerkats), these
 factors had a limited effect on prenatal growth, and adjustments to
 gestation lengths were modest and unrelated to social factors. Pups that
 grew faster in utero were heavier when they emerged from the birth burrow,
 yet this rapid growth was not associated with shortened leukocyte
 telomeres, and they were consequently more likely to survive to adulthood.
 Broadly, we identified pronounced variation in gestational weight gains,
 which is largely driven by food availability and strongly predicts
 offspring birth weights and survival. Our findings also highlight
 constraints in the flexibility of prenatal growth and gestation lengths in
 this species, which may limit adjustments in response to prevailing social
 conditions, and enhance selection for flexibility in postnatal growth.
description: # The ecology of gestational growth in a wild cooperative mammal Dataset
 DOI: [10.5061/dryad.j6q573nv5](https://doi.org/10.5061/dryad.j6q573nv5) ##
 Description of the data and file structure The following R code and data
 are presented in support of our paper 'The ecology of gestational
 growth in a wild cooperative mammal', published in the Journal of
 Animal Ecology. The R code was produced by Dr Jack Thorley and relies
 extensively on the use of the tidyverse suite for data wrangling and
 plotting
 ([https://www.tidyverse.org/packages/](https://www.tidyverse.org/packages/)), and the brms package for the fitting of Bayesian hierarchical models ([https://paul-buerkner.github.io/brms/](https://paul-buerkner.github.io/brms/)). The Variance inflation functions come directly from Zuur et al.'s 2009 book *Mixed Effects Models with Extensions in Ecology with R*. Also, please note that all identifying information (ReprodRef, FemaleID, GroupRef, PupID) has been anonymised within this analysis. One should not, therefore, attempt to link these identifiers with those provided in other papers produced by the meerkat project.  A full breakdown of the contents of the data files and associated R scripts now follows.  #### File: MeerkatGestation_AllPregs.csv **Description:** Body weights across all pregnancies ##### Variables * ReprodRef: Unique identifier for each pregnancy * FemaleID: Unique identifier for each pregnant female * GroupRef: Unique identifier for each meerkat group * DomStatus: Dominance status ["dominant", "subordinate"] * LitterSize: The size of the birthed litter * BirthDate: The birth date of the litter/end of the pregnancy * WeightDate: The date when body weight was measured * Weight: Body weight in grams * PregnancyDay: The day of the pregnancy (relative to the birth date) * trimester: Pregnancy trimester ["first", "second", "third"] * BreedingSeason: The breeding season in which the pregnancy started. Seasons run from July 1st of one year to June 30th of the following year. * MotherAgeAtConception: Mother's age at the point of conception, in days * AvgGroupSizeAtConception:  The average number of adults in the group in the 30 days prior to conception * NumberOtherFemalesHeavilyPregDuringFinalTrimester: The number of pregnant females in their third trimester during the focal female’s third trimester * BodyConditionAtConception: The mean residual body weight in the two weeks prior to the start of each pregnancy (see Supporting information for estimation) * ndvi_startpreg: The mean normalised difference vegetation index (NDVI) across the population’s range in the first half of pregnancy. * maxtemp_wholepreg:  The mean daily maximum air temperature in degrees C across pregnancy * maxtemp_startpreg:  The mean daily maximum air temperature in the first half of pregnancy * maxtemp_endpreg:  The mean daily maximum air temperature in the second half of pregnancy #### File: MeerkatGestation_EstrusPregs.csv **Description:** Body weights for the pregnancies with h known conception date ##### Variables * ReprodRef: Unique identifier for each pregnancy * FemaleID: Unique identifier for each pregnant female * GroupRef: Unique identifier for each meerkat group * LitterSize: The size of the birthed litter * BodyConditionAtConception: The mean residual body weight of the two weeks prior to the start of each pregnancy (see Supporting information for estimation) * BreedingSeason: The breeding season in which the pregnancy started. Seasons run from July 1st of one year to June 30th Jof une the following year. * AccurateConceptionDate: The date of conception, according to the observed estrus/mating event * BirthDate: The birth date of the litter/end of the pregnancy * WeightDate: The date when body weight was measured * Weight: Body weight in grams * PregnancyDay: The day of the pregnancy (relative to the birth date) * PregLength: The total pregnancy length in days, from conception to birth #### File: MeerkatGestation_PupFitness.csv **Description:** Fitness consequences of gestational weight changes for pups ##### Variables * PupID: Unique identifier for each pup * PupSex: The sex of the pup ["F", "M"] * ReprodRef: Unique identifier for each pregnancy * MotherID: Unique identifier for each pregnant female * GroupRef: Unique identifier for each meerkat group * BreedingSeason: The breeding season in which the pregnancy started. Seasons run from July 1st of one year to June 30th of the following year. * BirthDate: The birth date of the litter/end of the pregnancy * AgeAtFirstWeight: The age at which the pup was first weighed in days (i.,e. after emerging above ground) * PupFirstEmergenceWeight: The weight of the pup on emergence * Survive90Days: Whether the pup survived to 90 days ["0", "1", "NA"] * Survive1Year: Whether the pup survived to 1 year ["0", "1", "NA"] * Telomere_length: The length of the pup's telomeres (T/S ratio) * Telomere_CapAge: The pup's age when the telomere was sampled and collected * LitterSize: The size of the birthed litter * MotherAgeAtConception: The age of the mothers at conception in days * MotherDomStatusAtBirth: Dominance status of the mother at birth ["dominant", "subordinate"] * AvgGroupSizeAtBirth: The number of adults in the group at birth * MotherAgeYrs: The mother's age in years * PupAgeAtDeath: The age at which the pup later died, when known, in days #### File: MeerkatGestation_SuppFeeding.csv **Description:** Body weights for supplementally fed mothers during pregnancies and time-matched control litters ##### Variables * ReprodRef: Unique identifier for each pregnancy * FemaleID: Unique identifier for each pregnant female * GroupRef: Unique identifier for each meerkat group * DomStatus: Dominance status ["dominant", "subordinate"] * LitterSize: The size of the birthed litter * Treatment: Was the mother fed or unfed ["Fed", "Control" ] * BirthDate: The birth date of the litter/end of the pregnancy * WeightDate: The date when body weight was measured * Weight: Body weight in grams * PregnancyDay: The day of the pregnancy (relative to the birth date) * FedControlPairing: The unique identifier for each fed vs control pairing #### File: MeerkatGestation_SuppFeedingSumm.csv **Description:** A summary of the fed and control pregnancies for the supplementary feeding comparisons ##### Variables * FedReprodRef: Unique identifier for the pregnancy of the fed mother * FedFemaleID: Unique identifier for the identity of the fed mother * FedDomStatusAtConception: Dominance status of the mother at birth ["dominant", "subordinate"] * FedBirthDate: The birth date of the litter/end of the pregnancy * FedLitterSize: The birth date of the litter/end of the pregnancy for the fed mother * FedBodyConditionAtConception: The body condition of the fed mother at conception (see BodyConditionAtConception in other data sets) * ControlReprodRef: Unique identifier for the pregnancy of the control mother * ControlFemaleID: Unique identifier for the identity of the control mother * ControlBirthDate: The birth date of the litter/end of the pregnancy for the control mother * ControlLitterSize: The size of the control female's litter * ControlBodyConditionAtConception: The body condition of the control mother at conception (see BodyConditionAtConception in other data sets) * ControlDomStatus: Dominance status of the control mother at birth ["dominant", "subordinate"] * TimeDiff: Time difference in days between the two litters being directly compared * FedControlPairing: The unique identifier for each fed vs control pairing ## Code/software All data were wrangled, visualised, and analysed using R version 4.2.2. All code is provided in the following five scripts:  #### File: 1_MkatGestationalGrowth_ShapeOfGrowth.R **Description:** Characterising the shape of gestational growth #### File: 2_MkatGestationalGrowth_FactorsAffectingGrowth.R **Description:**  Investigating the factors affecting gestational weight dynamics #### File: 3_MkatGestationalGrowth_FeedExperiment.R **Description:** Investigating the effect of supplemental feeding on gestation weight dynamics #### File: 4_MkatGestationalGrowth_FitnessConsequences.R **Description:**  Modelling pregnancies of known length to determine the extent to which mothers can modify gestation lengths #### File: 5_MkatGestationalGrowth_EstrusandMating.R **Description:** Exploring the fitness consequences of gestational weight gain for pup development #### File: VIFfunctions.R **Description:** Variance inflation factors to check collinearity among continuous variables (Zuur, 2009) ## Access information Other publicly accessible locations of the data: * Not applicable Data was derived from the following sources: * All data were collected as part of routine long-term sampling of the meerkat population that has been studied at the Kalahari Research Centre for the past three decades ([https://kalahariresearchcentre.org/)](https://kalahariresearchcentre.org/)