Data from: Individual variation in early-life telomere length and survival in a wild mammal

Individual variation in survival probability due to differential responses
to early-life environmental conditions is important in the evolution of
life-histories and senescence. A biomarker allowing quantification of such
individual variation, and which links early-life environmental conditions
with survival by providing a measure of conditions experienced, is
telomere length. Here, we examined telomere dynamics among 24 cohorts of
European badgers (Meles meles). We found a complex cross-sectional
relationship between telomere length and age, with no apparent loss over
the first 29 months, but with both decreases and increases in telomere
length at older ages. Overall, we found low within-individual consistency
in telomere length across individual lifetimes. Importantly, we also
observed increases in telomere length within individuals, which could not
be explained by measurement error alone. We found no significant sex
differences in telomere length, and provide evidence that early-life
telomere length predicts lifespan. However, while early-life telomere
length predicted survival to adulthood (≥1 year old), early-life telomere
length did not predict adult survival probability. Furthermore, adult
telomere length did not predict survival to the subsequent year. These
results show that the relationship between early-life telomere length and
lifespan was driven by conditions in early-life, where early-life telomere
length varied strongly among cohorts. Our data provide evidence for
associations between early-life telomere length and individual
life-history, and highlight the dynamics of telomere length across
individual lifetimes due to individuals experiencing different early-life
environments.