Male polyterritoriality and imperfect female choice in the pied flycatcher, Ficedula hypoleuca

Polyterritoriality, the occupation of two spatially separate territories by male birds, has been suggested to enable males to conceal their pairing status. The idea that males deceive females has recently been questioned with arguments that females would easily be able to detect polyterritorial males and that they mate in the second territories because better breeding options are not available close by. We arranged for pied flycatcher (Ficedula hypoleuca) females a choice between neighboring unmated and already-mated males. Females were unable to discriminate against already-mated males, even though their breeding success thereby would have been increased. These results allow rejection of any polygyny models that assume females use male pairing status as a criterion for mate choice. Females would reduce the probability of mating polygynously by choosing dull, yearling males with high song rate, even though in most cases it is difficult to differentiate already-mated and unmated males. In fact, females did not prefer colorful males, opposing a general pattern found in other bird species. However, females did not specifically prefer dull males nor did they respond to slight differences in song rates. The seemingly nonadaptive, imperfect female behavior suggests that the evolution of female selectivity is constrained, allowing deception by males to be successful in the evolutionary "arms race" between the sexes. [Behav Ecol 1990;1:171-177]