Major seasonal life history events, such as reproduction, molt, and migration, can have vastly different energy demands. To meet these changing energy needs, various strategies can be employed to maintain energy balance, with each having inherent fitness costs and benefits. On one hand, birds can modulate energy intake by modifying foraging intensity. On the other, birds can regulate energy expenditure via activity and metabolism. However, our knowledge of how energy balance strategies vary across the annual cycle remains poor. The objective of this project is to characterize patterns of energy balance in Anna's hummingbirds (Calypte anna) during different seasons. Hummingbirds have among the highest metabolic rates of any vertebrate, yet their precious nectar resources fluctuate seasonally, all while they undergo energetically demanding annual life history events. Four weeks of data were collected during each of three seasons: summer molt, fall migration, and winter. Body mass, condition, molt status, and basal metabolic rate were measured weekly. Torpor frequency was estimated using thermal imaging. Feeding intake and activity were measured daily. As environmental conditions continue to shift drastically in the face of climate change, studying these patterns can help shed light on energy and resource use across the year.