Data from: Parental age influences offspring telomere loss

The age of the parents at the time of offspring production can influence
offspring longevity, but the underlying mechanisms remain poorly
understood. The effect of parental age on offspring telomere dynamics
(length and loss rate) is one mechanism that could be important in this
context. Parental age might influence the telomere length that offspring
inherit or age-related differences in the quality of parental care could
influence the rate of offspring telomere loss. However, these routes have
generally not been disentangled. Here, we investigated whether parental
age was related to offspring telomere dynamics using parents ranging in
age from 2 to 22 years old in a free-living population of a long-lived
seabird, the European shag (Phalacrocorax aristotelis). By measuring the
telomere length of offspring at hatching and towards the end of the
post-natal growth period, we could assess whether any potential parental
age effect was confined to the post-natal rearing period. There was no
effect of maternal or paternal age on the initial telomere length of their
chicks. However, chicks produced by older mothers and fathers experienced
significantly greater telomere loss during the post-natal nestling growth
period. We had relatively few nests in which the ages of both parents were
known, and individuals in this population mate assortatively with respect
to age. Thus, we could not conclusively determine whether the parental age
effect was due to maternal age, paternal age, or both; however, it appears
that the effect is stronger in mothers. These results demonstrate that in
this species, there was no evidence that parental age was related to
offspring hatching telomere length. However, telomere loss during nestling
growth was reduced in the offspring of older parents. This could be due to
an age-related deterioration in the quality of the environment that
parents provide, or because parents that invest less in offspring rearing
live to an older age.