From courtship and nest building to protecting eggs and raising chicks, birds have an amazing array of mating behaviors and family strategies. In this eye-opening look, evolutionary biologist Wenfei Tong shares a host of surprising facts about birds we think we know, with striking photographs. Meet fairy-wrens, who sometimes have helpers at the nest that forgo their own reproduction cycles to assist the breeding pair. Among jacana, the males perform the childcare, while cuckoos leave their eggs in the nests of other species. And though puffins do indeed mate for life, dunnocks seek as many partners as possible.