Every fall, Salem transforms from a sleepy city on the North Shore to a bustling tourist destination faster than the leaves can change color. People come from all around the globe to soak in the spooky atmosphere and learn about the city’s ties to the Salem Witch Trials. Small businesses line the streets, selling everything from $80 palm readings to hand-made witch hats. 

David Alexander, a scientist at the University of Kansas and the author of “On the Wing: Insects, Pterosaurs, Birds, Bats and the Evolution of Animal Flight,” always had an interest in flight. His...