Pair-bonding in birds and the active role of females: a critical review ofthe empirical evidence

Over the recent years the role of females in maintaining or breaking the pa ir-bond in socially monogamous birds has received growing attention. Here, we review the overall evidence for a direct and predominant role of female behaviour in initiating or preventing divorce and its relevance for the und erstanding of both interspecific and intraspecific variation in divorce rat e in monogamous bird species. The evidence is so far limited to a few speci es. We discuss the relevance of some alternative explanations and confoundi ng factors. We conclude that the possible predominance of females in both i nitiating divorce or limiting its occurrence deserves further consideration . Future studies should favour experimental approaches, such as mate-remova l experiments. (C) 2000 Published by Elsevier Science B.V. All rights reser ved.