Data from: Early-life stress strengthens trait covariance: a plastic response that results in reduced flexibility

Stress exposure during development can impact both the expression of
individual traits and associations between traits, but whether stress
results in stronger or weaker associations between traits is unclear. In
this study, we examined within and among-trait associations for
morphological and physiological traits in zebra finches (Taeniopygia
guttata) exposed to corticosterone (CORT) during the nestling and
fledgling stages, and in control birds. Birds exposed to CORT exhibited
stronger correlations within traits and stronger associations among
traits. We found preliminary evidence that birds that died before the
median age of death had stronger within and among-trait correlations
independent of treatment, and among CORT-treated birds, smaller birds were
more likely to survive beyond the median age than larger birds. These
findings suggest that early-life stress hormone exposure can result in
reduced developmental flexibility, with potential fitness ramifications,
and that these costs may be greater for larger offspring. Furthermore, our
results provide experimental evidence for pleiotropic effects of hormones
during development through altered patterns of phenotypic correlation.