INITIAL PERSPECTIVES; 1. Introduction: pair bonds and partnerships; 2. The battle of the sexes and the origins of monogamy; 3. The model family; CONTINUOUS PARTNERSHIPS; 4. Long-term monogamy in a river specialist - the Blue Duck; 5. Do Barnacle Geese benefit from life-long monogamy?; 6. Mate fidelity in swans; 7. Breeding partnrship in two New World jays; 8. Partnerships in promiscuous Splendid Fairy-wrens; PART-TIME PARTNERSHIPS; 9. Divorce in the European Blackbird; 10. Mate fidelity and divorce in ptarmigan; 11. Causes and consequences of long-term partnerships in Cassin's Auklets; 12. Monogamy in a long-lived seabird: the Short-tailed Shearwaters; 13. Between and within-population variation in mate fidelity in the Great Tit; 14. Monogamy in the Sparrowhawk; 15. Mate fidelity in penguins; 16. Causes and consequences of mate fidelity in Red-billed Gulls; 17. Dispersal, demography, and the persistence of partnerships in Indigo Buntings; Concluding Perspectives; 18. Monogamy and sperm competition in birds; 19. Mate fidelity and divorce in monogamous birds; Author index; Subject index