TELOMERE LENGTH DIFFERENCES INDICATE CLIMATE CHANGE-INDUCED STRESS AND
POPULATION DECLINE IN A MIGRATORY BIRD
Abstract
Genomic projections of (mal)adaptation under future climate change,
known as genomic offset, faces limited application due to challenges in
validating model predictions. Individuals inhabiting regions with high
genomic offset are expected to experience increased levels of
physiological stress as a result of climate change, but documenting such
stress can be challenging in systems where experimental manipulations
are not possible. One increasingly common method for documenting
physiological costs associated with stress in individuals is to measure
the relative length of telomeres – the repetitive regions on the caps
of chromosomes that are known to shorten at faster rates in more adverse
conditions. Here we combine models of genomic offsets with measures of
telomere shortening in a migratory bird, the yellow warbler (Setophaga
petechia), and find a strong correlation between genomic offset,
telomere length, and population decline. While further research is
needed to fully understand these links, our results support the idea
that birds in regions where climate change is happening faster are
experiencing more stress and that such negative effects may help explain
the observed population declines.