Wonderful news today in that Dr. Christine Madliger’s paper entitled “Conservation implications of a lack of relationship between baseline glucocorticoids and fitness in a wild passerine” was just accepted for publication in Ecological Applications. To test whether baseline glucocorticoids are the simple biomarker of environmental change we assume they are, Christine set out to examine the relationship between baseline plasma corticosterone at two different breeding stages and three metrics of fitness (offspring quality, reproductive output, and adult survival) in wild female tree swallows. Importantly, Christine investigated these relationships in both natural conditions and under an experimental manipulation of foraging profitability. She found a lack of relationship between baseline GCs and both short- and long-term metrics of fitness in control and experimental birds, suggesting that baseline GCs cannot be easily employed as conservation biomarkers across some species and life history stages. Taken together, Christine’s work stresses the importance of ground-truthing GC-fitness relationships before making broad assumptions. This paper is a very important and continuing step in testing and therefore establishing the underlying relationships between environmental variation, baseline GCs and fitness. Wonderful work Christine.