The transition between the breeding and nonbreeding states is often marked by a shift in energy balance. Despite this well‐known shift in energy balance, little work has explored seasonal differences in the orexigenic neuropeptides that regulate food intake in wild animals. Here we tested the hypothesis that free‐living male song sparrows (Melospiza melodia) show seasonal changes in energetic state, circulating steroids, and both neuropeptide Y (NPY) and orexin (OX) immunoreactivity. Nonbreeding song sparrows had more fat and muscle, as well as a ketone and triglyceride profile suggesting a greater reliance on lipid reserves. Breeding birds had higher plasma androgens; however, nonbreeding birds did maintain androgen precursors in circulation. Nonbreeding birds had more NPY immunoreactivity, specifically in three brain regions: lateral septum, bed nucleus of the stria terminalis, and ventral tegmental area. Furthermore, nonbreeding birds had more OX immunoreactivity in multiple brain regions. Taken together, the data indicate that a natural shift in energy balance is associated with changes in NPY and OX in a region‐specific manner. Seasonal variation in immunoreactivity of neuropeptide Y or NPY (above) and orexin (below) were investigated in sparrows. Nonbreeding birds had higher NPY and orexin immunoreactivity than breeding birds throughout the brain, including areas that regulate social behavior. This coincided with nonbreeding shifts in fat reserve usage and circulating steroid profiles. [ABSTRACT FROM AUTHOR]