Data from: Developmental stress and telomere dynamics in a genetically polymorphic species

A central objective of evolutionary biology is understanding variation in
life-history trajectories and aging rate, or senescence. Senescence can be
affected by tradeoffs and behavioral strategies in adults, but may also be
affected by developmental stress. Developmental stress can accelerate
telomere degradation, with long-term longevity and fitness consequences.
Little is known regarding whether variation in developmental stress and
telomere dynamics contribute to patterns of senescence during adulthood.
We investigated this question in the dimorphic white-throated sparrow
(Zonotrichia albicollis), a species in which adults of the two morphs
exhibit established differences in behavioral strategy and patterns of
senescence, and also evaluated the relationship between oxidative stress
and telomere length. Tan morph females, which exhibit high levels of
unassisted parental care, display faster reproductive senescence than
white females, and faster actuarial senescence than all of the other
morph-sex classes. We hypothesized that high oxidative stress and telomere
attrition in tan female nestlings could contribute to this pattern, since
tan females are small and potentially at a competitive disadvantage even
as nestlings. Nestlings that were smaller than nest mates had higher
oxidative stress, and nestlings with high oxidative stress and fast growth
rates displayed shorter telomeres. However, we found no consistent
morph-sex differences in oxidative stress or telomere length. Results
suggest that oxidative stress and fast growth contribute to developmental
telomere attrition, with potential ramifications for adults, but that
developmental oxidative stress and telomere dynamics do not account for
morph-sex differences in senescence during adulthood.