Evidence for baseline glucocorticoids as mediators of reproductive investment in a wild bird.

Highlights: [•] Individual baseline GCs were followed across two reproductive attempts. [•] Current reproductive investment was experimentally reduced. [•] Individuals responded by increasing future reproductive investment. [•] Inter-individual flexbility in baseline GCs predicted the increase in investment. [•] Flexibility in baseline GCs prepare individuals for predictable changes. [Copyright &y& Elsevier]