What crucial characteristic, shared by all members of Class Aves, is essential for the Wood Duck's active lifestyle?

Being endothermic, maintaining a high, regulated body temperature.

Membership in the Class Aves requires the Wood Duck to possess several defining traits, including feathers and laying hard-shelled eggs. Perhaps the most vital trait supporting its active existence—including agile flight and complex behaviors—is being endothermic. Endothermy means the bird actively generates and regulates its own high internal body temperature, independent of ambient environmental conditions. This constant, high level of internal heat production is necessary to fuel the high metabolic demands associated with flight and maintaining the necessary energy levels for foraging, courtship displays, and navigating their varied habitat, distinguishing them physiologically from ectothermic organisms.