Data from: Repeated experimental challenges do not shorten adult telomeres in a songbird

Responding to environmental challenges can have both positive and negative
effects on fitness, but the mechanisms and/or biomarkers underlying these
links are not well understood. Telomeres, repetitive sections of DNA that
form protective caps at chromosome ends, which enhance genome integrity
and often predict organismal lifespan, may be important in this context.
Some evidence suggests that stress exposure shortens telomeres, but most
studies are correlational and/or conducted during early life; thus, how
stress exposure influences telomeres in adulthood is not well known. Here
we experimentally exposed wild-captured adult house sparrows (Passer
domesticus) to a series of standardized protocols of repeated, rotating
stressors (including threats, unpredictable food availability, and immune
challenges) designed to increase stress levels. Although there were some
effects of the treatment on glucocorticoid levels and mass dynamics, there
were no effects on telomeres during any of the 6-11 month studies. Taken
together, these results suggest that telomeres are robust or resilient to
a range of stressors in adulthood. The effects of stress exposures on
telomeres are likely to be highly context-dependent and vary depending on
the timing, intensity, and duration of the stress exposures as well as an
individual’s life stage.