Skip to main content
Dryad logo

Data from: Heritable variation in circulating glucocorticoids and endocrine flexibility in a free-living songbird

Citation

Stedman, Jocelyn M.; Hallinger, Kelly K.; Winkler, David W.; Vitousek, Maren N. (2017), Data from: Heritable variation in circulating glucocorticoids and endocrine flexibility in a free-living songbird, Dryad, Dataset, https://doi.org/10.5061/dryad.15081

Abstract

Phenotypic flexibility is a central way that organisms cope with challenging and changing environments. As endocrine signals mediate many phenotypic traits, heritable variation in hormone levels, or their context-dependent flexibility, could present an important target for selection. Several studies have estimated the heritability of circulating glucocorticoid levels under acute stress conditions, but little is known about the potential for either baseline hormone levels or rapid endocrine flexibility to evolve. Here we assessed the potential for selection to operate on the elevation (circulating hormone levels) and flexibility of glucocorticoid reaction norms to acute restraint stress. Multivariate animal models revealed low but significant heritability in baseline (h2=0.13-0.14) and stress-induced glucocorticoids (h2=0.18), and moderate heritability in glucocorticoid flexibility in response to acute stress (h2=0.38) in free-living juvenile tree swallows (Tachycineta bicolor; n=408). Baseline glucocorticoids were not genetically correlated with either stress-induced glucocorticoids or glucocorticoid flexibility. These findings indicate that baseline glucocorticoids and the acute stress response are distinct traits that can be independently shaped by selection. Microevolutionary changes that influence the expression or flexibility of these endocrine mediators of phenotype may be an important way that populations adapt to changing environments and novel threats.

Usage Notes

Funding

National Science Foundation, Award: IOS-1457251, LTREB DEB-0717021

Location

New York State