DOI: 10.5061/dryad.1c59zw48k
title: Data from: Effects of parental age at conception on offspring life history trajectories in a long-lived bird

description: Parental age at conception can have both short- and long-term consequences
 on the health, survival, and reproduction of their offspring. To date,
 most of our knowledge comes from laboratory studies, which consider the
 effects of maternal age and a “snapshot” of the life history trajectory of
 the offspring. Here, we use a multigenerational demographic dataset in a
 free-living, long-lived (median lifespan is 7 years old) bird, the Alpine
 swift (Tachymarptis melba), to investigate the effects of maternal and
 paternal age on offspring traits, from nestling to adulthood, and
 considering all major life history traits, from growth and age at first
 reproduction to reproductive success and lifespan. Parental age affected
 offspring phenotype before fledging and lifespan, but differently so for
 sons and daughters. Offspring from old-age mothers (≥ 11 years old) and
 fathers (≥ 9 years old) were bigger and less infested by ectoparasites
 before fledging, except sons from old-age fathers that show no reduction
 in ectoparasite load. We also report evidence of negative effects of
 paternal age on the lifespan of their offspring (i.e., Lansing effect),
 with sons (but not daughters) from old-age fathers having shorter
 lifespans. Our findings highlight the importance of the transgenerational
 effects of parental age at conception on the reproductive performance,
 survival, and phenotype of their offspring.
description: # Data from: Effects of parental age at conception on offspring life
 history trajectories in a long-lived bird Dataset DOI:
 [10.5061/dryad.1c59zw48k](10.5061/dryad.1c59zw48k) ## Description of the
 data and file structure Dataset on Alpine swift life history traits at
 adulthood (age at first reproduction, lifespan, lifetime reproductive
 success) and phenotype at fledging (mass, size, ectoparasite load)
 associated with the article entitled "*Effects of parental age at
 conception on offspring life history trajectories in a long-lived
 bird*" by Moullec H., Berger V., Meier C., Reichert S. and Bize P.,
 published in *Evolution*. ### Files and variables #### File:
 Evolution_AFR_swift_08.2025.xlsx **Description:** Dataset: parental age
 effect at conception on offspring age at first reproduction #####
 Variables * ring: offspring ID * mother: mother ID * father: father ID *
 year_birth: year of birth of the offspring/year when the data were
 collected * colony: city where the data have been collected: Solothurn
 (Bieltor, BT) and Biel (Stadtkirche, SK) * sex: sex of the individual,
 male (M) or female (F) * age_mother: age of the mother at conception in
 years * age_father: age of the father at conception in years * AFR: age at
 first reproduction in years * annual_nestling_survival: mean proportion of
 offspring who survived from hatching up to fledging in the colonies  in
 the year of birth of a focal offspring * mother_age_category: maternal age
 at conception as a 2-level factor: prime-age (2 to 10 years of age) or
 old-age (&gt;10 years of age) * father_age_category: paternal age at
 conception as a 2-level factor: prime-age (2 to 8 years of age) or old-age
 (&gt;8 years of age) * lifespan_mother: lifespan of the mother in years *
 lifespan_father: lifespan of the father in years 
 
 #### File: Evolution_Lifespan_swift_08.2025.xlsx
 **Description:** Dataset: parental age effect at conception on offspring
 lifespan ##### Variables * ring: offspring ID * mother: mother ID *
 father: father ID * year_birth: year of birth of offspring/year when the
 data were collected * colony: city where the data have been collected:
 Solothurn (Bieltor, BT) and Biel (Stadtkirche, SK) * sex: sex of the
 individual, male (M) or female (F) * age_mother: age of the mother at
 conception in years * age_father: age of the father at conception in years
 * lifespan: lifespan in years * annual_nestling_survival: mean proportion
 of offspring who survived from hatching up to fledging in the colonies  in
 the year of birth of a focal offspring * mother_age_category: maternal age
 at conception as a 2-level factor: prime-age (2 to 10 years of age) or
 old-age (&gt;10 years of age) * father_age_category: paternal age at
 conception as a 2-level factor: prime-age (2 to 8 years of age) or old-age
 (&gt;8 years of age) * lifespan_mother: lifespan of the mother in years *
 lifespan_father: lifespan of the father in years #### File:
 Evolution_LRS_swift_08.2025.xlsx **Description:** Dataset: parental age
 effect at conception on offspring lifetime reproductive success #####
 Variables * ring: offspring ID * mother: mother ID * father: father ID *
 year_birth: year of birth of offspring/year when the data were collected *
 colony: city where the data have been collected: Solothurn (Bieltor, BT)
 and Biel (Stadtkirche, SK) * sex: sex of the individual, male (M) or
 female (F) * age_mother: age of the mother at conception in years *
 age_father: age of the father at conception in years * LRS: lifetime
 reproductive success * annual_nestling_survival: mean proportion of
 offspring who survived from hatching up to fledging in the colonies  in
 the year of birth of a focal offspring * mother_age_category: maternal age
 at conception as a 2-level factor: prime-age (2 to 10 years of age) or
 old-age (&gt;10 years of age) * father_age_category: paternal age at
 conception as a 2-level factor: prime-age (2 to 8 years of age) or old-age
 (&gt;8 years of age) * lifespan_mother: lifespan of the mother in years *
 lifespan_father: lifespan of the father in years #### File:
 Evolution_Offspring_phenotype_swift_08.2025.xlsx **Description:** Dataset:
 parental age effect at conception on offspring phenotype at 50 days after
 hatching (close to fledging) ##### Variables * ring: offspring ID *
 mother: mother ID * father: father ID * year_birth: year of birth of
 offspring/year when the data were collected * colony: city where the data
 have been collected: Solothurn (Bieltor, BT) and Biel (Stadtkirche, SK) *
 hatching_date: hatching day 1 corresponds to May 1st; 32 is June 1st *
 age_days: exact age of the offspring in days * hour_measurement: hour of
 measurement reported as numerical value (e.g. 8h45min = 8.75) * body_mass:
 body mass grams; measured to the nearest 0.1 g using a digital scale *
 wing_length: wing length in mm; measured to the nearest 1 mm using a ruler
 * sternum_length: sternum length in mm; measured to the nearest 0.1mm
 using a caliper * parasite_load: total number of louse-flies (Craterina
 melbae; Hipposboscidae; Diptera) counted in the plumage of the bird *
 tail_length: tail length in mm; measured to the nearest 1mm using a ruler
 * brood_size: number of chicks in the nest at 50 days * sex: sex of the
 individual, male (M) or female (F) * age_mother: age of the mother at
 conception in years * age_father: age of the father at conception in years
 * annual_nestling_survival: mean proportion of offspring who survived from
 hatching up to fledging in the colonies  in the year of birth of a focal
 offspring * mother_age_category: maternal age at conception as a 2-level
 factor: prime-age (2 to 10 years of age) or old-age (&gt;10 years of age)
 * father_age_category: paternal age at conception as a 2-level factor:
 prime-age (2 to 8 years of age) or old-age (&gt;8 years of age) *
 lifespan_mother: lifespan of the mother in years * lifespan_father:
 lifespan of the father in years #### File: Evolution_R_script_08.2025.R
 **Description:** This R script analyzes the impact of parental age at
 conception on various offspring life-history traits (such as age at first
 reproduction, lifespan, lifetime reproductive success, and physical
 phenotype) in a long-lived bird species, using mixed-effect models and
 visualizations. ## Code/software R script associated with the article
 entitled "Effects of parental age at conception on offspring life
 history trajectories in a long-lived bird" by Moullec H., Berger V.,
 Meier C., Reicher, T.S., and Bize P., published in Evolution. Data
 courtesy of P. Bize et al.
 ([pierre.bize@vogelwarte.ch](mailto:pierre.bize@vogelwarte.ch)), Swiss
 Ornithological Institute, CH-6204 Sempach