DOI: 10.5061/dryad.7d7wm384j
title: No evidence of early life resource pulse effects on age-specific variation in survival, reproduction and body mass of female Siberian flying squirrels

description: Understanding the diversity and causes of senescence patterns in the wild
 remains a challenging task, in particular among fast-living species for
 which senescence patterns have been poorly studied. Early life
 environmental conditions can shape senescence by influencing trade-offs
 between early and late life performance (disposable soma theory) or
 individual fitness through lifelong positive effects (silver spoon
 effects). Using a 23-year-long monitoring dataset of two populations of
 Siberian flying squirrels (Pteromys volans L.) in western Finland, we
 analysed the occurrence, onset and rate of senescence in female survival,
 body mass and reproductive performance. We also examined how early-life
 pulsed resources (tree masting during the year of birth) influence
 age-specific variations in these traits. Our results indicate that
 survival senescence occurs after sexual maturity from 3 years of age.
 Females experiencing high resource availability at birth tended to survive
 better, but the age-specific trend was not affected by early-life resource
 conditions. Maternal body mass declined slightly with age, starting at 4
 years, regardless of early resource conditions. Similarly, among
 reproductive traits, we showed late-onset senescence in both litter size
 and annual reproductive probability, with no evidence supporting an effect
 of early life resources on these trends. We found no decline in juvenile
 body mass or in the juvenile size-number trade-off with maternal age. Our
 findings suggest that pulsed resources experienced at birth have a limited
 long-lasting impact on the life-history traits of this fast-living rodent,
 with no significant effect on senescence patterns. 
description: # Data from: No evidence of early life resource pulse effects on
 age-specific variation in survival, reproduction and body mass of female
 Siberian flying squirrels Le Coeur C., Berger V., Lummaa V., Wistbacka R,
 Selonen V.
 [https://doi.org/10.5061/dryad.7d7wm384j](https://doi.org/10.5061/dryad.7d7wm384j) ### Files and variables #### File: Le\_Coeur\_et\_al\_FlyingSquirr\_ReproData.csv To open the file in R, use: `read.csv2("Yourpath/Le_Coeur_et_al_FlyingSquirr_ReproData.csv")` **Description:** Data file containing litter size and annual reproductive probability (ARP) for each female monitored during the study period (1992-2014). Litter size is defined as the number of juveniles per litter. For a given year, we considered litter sizes from the 1st and 2nd reproductive events of females that were observed at least during the first reproductive event (the main reproductive event). ##### Variables ID - ID assigned to each female individual (mother) BirthYr - the year in which the female was born Year - Year of monitoring MarkingAge - Age at marking. Two levels: marked as "juvenile" or "adult" Site - Two levels: "Vaasa" or "Luoto" study site Season - Reproductive event during which nest boxes were checked, in June ("Breed1") or in August ("Breed2") No.juv - Female's litter size, defined as the number of juveniles per litter Patch - Forest patch where the nest box was located (levels correspond to patch names) Age - Age of the female (in years) AFR - Age of first reproduction: the age at which the female was first known to reproduce (in years) ALR - Age of last reproduction: the age at which the female was last known to reproduce (in years) ARP - Annual Reproductive Probability ("0" if a female did not reproduce in either breeding season and "1" if it reproduced in one or both seasons) AnnualFood - food availability in year t (composite variable). After scaling the annual estimates of masting alder and birch resource availability separately, we averaged the two scaled variables per year. BirthFood - food availability during the female's first year of life (composite variable) #### File: Le Coeur\_et\_al\_FlyingSquirr\_JuvBodyMass.csv To open the file in R, use: `read.csv2("Yourpath/Le_Coeur_et_al_FlyingSquirr_JuvBodyMass.csv")` **Description:** Data file of juvenile body mass, recorded during the first reproductive season between 1992 and 2014. ##### Variables JuvBodyMass - Juvenile body mass in grams Year - The year in which the juvenile was born DaySinceJan1 - Day of juvenile body mass measurement during the reproductive season, counted from January 1. MotherID - ID assigned to the mother Site - Two levels: "Vaasa" or "Luoto" study site No.juv - The number of juveniles in the litter to which the weighed juvenile belongs Patch - Forest patch where the nest box was located (levels correspond to the patch names) MotherAge - Maternal age (in years) AFR - Age of first reproduction: the age at which the mother was first known to reproduce (in years) ALR - Age of last reproduction: the age at which the mother was last known to reproduce (in years) MarkingAge - Maternal age at marking. Two levels: marked as "juvenile" or "adult" AnnualFood - food availability in year t (composite variable). After scaling the annual estimates of masting alder and birch resource availability separately, we averaged the two scaled variables per year. BirthFood - food availability during the mother's first year of life (composite variable). #### File: Le Coeur\_et\_al\_FlyingSquirr\_MaternalBodyMass.csv To open the file in R, use: `read.csv2("Yourpath/Le_Coeur_et_al_FlyingSquirr_MaternalBodyMass.csv")` **Description:** Data file of maternal body mass, recorded between 1992 and 2014. ##### Variables BodyMass - Maternal body mass (in grams) ID - ID assigned to the female BirthYr - the year in which the female was born Year - Year of monitoring MarkingAge - Age at marking. Two levels: marked as "juvenile" or "adult" Site - Two levels: "Vaasa" or "Luoto" study site Patch - Forest patch where the nest box was located (levels correspond to the patch names) ReproSeason - A two-level factor with “1” if the female was weighed during the reproductive period and "0" otherwise Age - Age of the female (from age 1 to age 6+ years) AFR - Age of first reproduction: the age at which the female was first known to reproduce (in years) ALR - Age of last reproduction: the age at which the female was last known to reproduce (in years) AnnualFood - food availability in year t (composite variable). After scaling the annual estimates of masting alder and birch resource availability separately, we averaged the two scaled variables per year. BirthFood - food availability during the female's first year of life (composite variable) #### File: Le Coeur\_et\_al\_FlyingSquirr\_Survival.csv To open the file in R, use: `read.csv("Yourpath/Le_Coeur_et_al_FlyingSquirr_Survival.csv", sep = ";", colClasses = c("ch" = "character"))` **Description:** The data file contains the maternal annual capture history used for survival analysis (CJS models using the R package 'RMark'). ##### Variables ch - capture history (the information on whether an individual was captured "1" or not "0" each year) for each female from 1992 to 2014 BirthFood - food availability during the female's first year of life (composite variable). After scaling the annual estimates of masting alder and birch resource availability separately, we averaged the two scaled variables per year. Site - Two levels: "Vaasa" or "Luoto" study site MarkingAge - Age at marking. Two levels: marked as "juvenile" or "adult" AgeAtFirstCapture - Female age at the first entry in the capture history. Four levels: "juvenile", "yearlings" (1 year of age), "twoyears" (2 years of age), "threeyears" (3 years of age). &gt;95% of the individuals enter the dataset as yearlings.