Diel variation in baseline glucocorticoid (GC) secretion influences energetics and foraging
behaviors. In temperate breeding, diurnal vertebrates, studies have shown that daily
patterns of baseline GC secretion are influenced by environmental photoperiod, with
baseline GCs peaking prior to sunrise to stimulate waking and foraging behaviors.
Measures of physiological energy acquisition are also expected to peak in response to
foraging activity, but their relationship to GC levels have not been well studied. In contrast to …