This is a succinct and intelligent story of changes, in which evolutions in the world at large are interposed among the evolutions in the bird world establishing cause-effect relationships that prove mutually clarifying. It is simply told with the aid of explicit photographs captioned informatively (not merely nominatively), and is particularly communicative because of the many effortless analogies written into the text: ""Its heart is a good motor for a flyer""; ""When all the breast meat is cut off and the bone is exposed, you can see that it is shaped like the keel of a boat."" The temporal spectrum encompassed is vast--from the dying out of ancient, now-fossilized birds to the futures of the 49 still-living flightless species. Penguins, ostriches, and other favorite zoo friends are featured, but just as much place is given to less familiar and equally extraordinary species like the rheas, cassowaries, grebes, wekas, and wattlebirds. All flocking together in instructive array for referring to or reading right through.