Data from: Effects of parental age at conception on offspring life history trajectories in a long-lived bird

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.