The cuckoos are the most variable birds in social behavior and parental care: a few cuckoos are among the most social of all birds and rear their young in a common nest; most cuckoos are caring parents that rear their own young with some females laying a few eggs in the nests of others; while many cuckoo species are brood parasites who leave their eggs in the nests of other birds to rear, with their young maturing to kill their foster nestmates. In The Cuckoos, Robert B. Payne presents a new evolutionary history of the family based on molecular genetics, and uses the family tree to explore...