The focus of this entry will be the adaptation for flight among bats, the only mammals to evolve structures for powered flight. Bats are not just fliers, they are mammalian, nocturnal fliers. Consequently, their adaptation to flight involves more than just the evolution of wings, but also requires solutions to nocturnal navigation, thermoregulatory problems, and energy considerations.
Over a span of 65 million years of evolutionary history, natural selection acted to balance several physical considerations to accommodate demands of flight: body mass and shape, wing morphology, flying style (i.e., control of wing shape, orientation, and motion), and physiology (to meet the energy requirements for flight).
To understand flight adaptation, it is useful to gain an understanding of the forces exerted on the animal in powered flight. Adaptation for flight of bats is guided by the need to generate and withstand, or minimize, these forces during flight. However, before looking at flight it is imperative to look at a prerequisite for nocturnal flight: some way to navigate in darkened space. Before flight could evolve in bats, a bat ancestor must have developed echolocation. There is more to being a flying bat than just having wings.