On the Wing: Insects, Pterosaurs, Birds, Bats and the Evolution of Animal Flight

Alexander guides readers through the anomalies of the flying world: hovering hummingbirds, unexpected gliders [squirrels, for instance], and the flyers that went extinct [pterosaurs]. Alexander also delves into wing-origin theory and explores whether birds entered the skies from the trees down [as gliders] or from the ground up [as runners] and uses the latest fossil evidence to present readers with an answer.